My son (6) and I recently rebuilt a small old cast iron BS engine. (Max rated rpm is ~2800 IIRC) He wants to do "something" with it. So I thought we would build a small 12v battery charger.
Looking for a small(ish) 1 wire alternator that has a low cut in speed. We'll use it to charge a small battery that is hooked to a perhaps (1500w?) inverter for a "proof of concept" project.
A 32 amp Delco 10si would be about right. No need for the 1 wire. Just get the pigtail plug and connect the red wire to the output lug on the alternator. That is how I run mine and the alternator can be turned on or off by pulling the plug.
Thanks Tom,
interestingly before I got to your reply I was considering the old "standard" 10 SI. Wile doing some reading I came across this Brushless 10SI. Might be interesting to give it a try.
http://dixie-electric.com/wp-content/uploads/2017/03/100-012-000.pdf
Forget the generator, power a go Kart with the motor. He'll get much more fun and you'll both get years of fond memories out of it.
Or charge his electric scooter!
I don't see a need for a fancy brushless unit. Just be aware that disconnecting the battery while running can blow the voltage regulator.
looks like a 10si will do the job. Thank you fella's
General Motors DelcoRemy 10SI's were the cats meow in mass production automotive alternators from 1972 until slowly rare to find used, "free". Say the 1990's.
Since you seem to be shopping for new or like new reconditioned why do you not step up your power-input to charge-out efficiency by at least 10%in one of the next generation later double internal fan units? NO. Not the even older than 10SI press-on pulley Chrysler's!
One of the mid-80's and on NipponDenso internal fans units. Off Honda's, Toyota's, Suburu's and others. Ha! Including then Chrysler/Dodge! Nothing more common than a C/D/P minivan externally regulated Denso alternator, used, take-off. External regulator then YOU get to choose you own single, dual, tree phase regulator strategy. And even kinda' sorta US/Canadian domestic.
Now MY favorite is the late 90's and later Ford/Motocraft dual internal fan units. Hinged/swing mounted. or pad mounted. Swap-out pulleys on the most common 17mm very shaft. You get the very low, low speed cut-in, very low rpm charging in an external removable piggyback voltage regulator/brush-holder package. Super long brushes. Easy 200,000 mile brushes/bearing service life (6500 service hours0. EASY to without splitting the cases or even unit dismounting to replace those brushes. OR, convert this unit to external, remote voltage regulation. Only been installed on ~15,000,000 Ford production units.
Oh. Your link shows this suppler to actually be using a 12/15SI unit. Heavier/denser/wider rotor pole unit than any 10SI. Wider lamination stack, with wider(longer) output stator coils. 12/15SI's have improved cooling with the ducted plastic fron fan and case haves at the stator cut outs. Opened up back case side to allow higher charging rates an not heat cook the internal regulator and output diodes.
Ha! All things done better in a smaller package dual internal fan unit.
Your actual amps produced past the units electro/magnetic built in maximum is usually determined by the battery/use loading demand. A vehicle engine had power to burn. Small engine like yours - NOT. That selected higher grade external regulator you should be spending the money on will have an adjustable charge rate setting.
All of these regulators internal, external you just have to learn the use and functions of the extra circuits terminal wires. Have the ability to NOT turn on charging loads until the engine warmed up enough to have stable power/rpm.
"One-wire" means lazy thinking you. Because. Ain't no such animal as a only caring about one-wire. That one-wire still needs a back to the battery return flow good,low resistance circuit leg. I have seen far too many of these disabled by pretty painting putting resistance into the alternator mounting. Seen Many, MANY undercharge batteries without a direct from the battery to the voltage regulator receiving-voltage feed-back wire. One of the two on the Delco 10/12/15/27SI systems.
Easy think: means easy to fail.
tree-farmer Steve unruh
Steve,
Having still not made any purchases. I have been thinking of perhaps skipping 12v and going to 24v lots of options, however not nearly 15,000,000 used.
What do you think?
https://www.ebay.com/sch/i.html?_odkw=24v+alternator&_osacat=177697&_from=R40&_trksid=p2045573.m570.l1312.R1.TR0.TRC2.A0.H0.TRS1&_nkw=24v+alternator&_sacat=177697
Your products links shows much.
Two of the units shown are double intenal fan units. The Denso for a Toyota forklift towards the begiining. And a Delco/Delphi 11SI, 3-4 up from the bottom of the listings. You can see that these are smaller overall for their wattage's than the other shown external front fan units. On these ALL of the cooling air must first be drawn trough the rear case openings cooling first the sensitive power diodes/regulator electronics. Heating that first-pass air. Then this heated air must be drawn past a very narrow internal rotating rotor to stationary stator gap. Lots of turbulence swirling there from the spinning rotor claw poles. Some stator lamination's and rotor cooling and further air heating takes place there in the center. This now reduceflow and further heated air flow finally cooling the front side stator copper winding; the front case bearing. The front bearing running HOT from lack of adequate cooling!! And heat transfered back from belt-to-pulley made heat.
The dual internal fan units do not relies on any rotor/stator gap air flow. Rear rotor fan suck in outside cool air first in the rear center cooling the rear bearing, rear electronics; then passing outward catching the rear stator output coils on the way out.
The front rotor fan sucks in outside cool air first past the front bearing; then out cooling the front side stator output coils.
A double doughnut inside-to-outside air/heat flows.
I cannot tell from you on-line text accent your geographical location. Toyota forklifts are worldwide.
IF you were EU I'd be looking seriously at Bosch(German) or Valeo(French)units. NOT American Delco/Delphi.
IF you were Asian/South America/Africa located then Korean Mando units in addition to the Japanese Denso's.
Use what is most common in your area.
THIS factor far outweighs hair-splitting % idealism's and perfections chasing.
tree-farmer Steve unruh
Regards
As far as 24 Vs 12 Volts go, First thing I'd thing of is what batteries are you going to charge in series for 24V? If you are going to run an inverter, is it 12 or 24V? You would want to match the alt to the Inverter if that is going to be a significant duty of the thing. Otherwise I would think that 12V would be a lot more handy for battery charging than a 24V output.
If this is just for occasional use and proof of concept with the odd use for the inverter, I wouldn't get too fussy over the alt you use.
I have played a lot with the Mitsubishi alts as found on Subarus and a lot of other jap cars. They are the twin fan type steve talks of and in my experience are virtually indestructible. I have run them flat out for hours and the heat coming out of them is surprising but they have never failed. One has to remember that the most sever duty in a stationary setup in free air is never going to come close to the stress the things are under in an engine bay as far as heat goes.
The Mitsubishis can be a 1, 2 or 3 wire setup depending on how much you want to control the things and what you class as a wire. There will obviously be an output and a ground and most have a Field wire. There is also a sense and the 3rd on the plug of the suby alts is for the computer to control the alt rather than it controlling itself. As I understand it, the computer more or less Cycles the alt rather than have it active all the time.
It lets the battery voltage get to say 13 V then kicks in till it's back to 15 or whatever. it then turns off till the low point is reached and kicks in again. This is different to a normal alt/ regulator that is energised all the time and tries to keep the system at a set point even if it is only putting out an amp.
The main thing with the 3 wire alts is to try and save fuel. makers claim the system saves 2% of fuel over the life of the vehicle... whatever that means. Good driving techniques would probably save 20%+ but whatever.
The computer can kick the alt in when it senses the car is over running say when the throttle is closed and the car is doing a certain speed or when the brakes are applied. It can turn the alt off when the vehicle is accelerating to lighten the load on the engine and benifit performance. Computers control the AC like this as well.
Wouldn't be much use in your application but just for interest sake....
I use the field wire for " overboost" if you like. Running it at battery voltage increases output at a fixed RPM. Tends to increase the battery voltage point as well.
The internal fan alts seem to take any punishment I can throw at them. I run loads direct with no battery and run the alts slower than they can make full power. Must load the hell out of them but never had one fail. Run them open circuit and switched in and out as you are not supposed to do and they don't give a fig about that either. Shorted them, reverse connected them, you name it. Can't blow the things up for want of trying.
The alts I get are 80A which is roughly 1 Kw. You can drive 2 at a time as I do on my lister engine but be aware you are going to need the power to do that. These things aren't terribly efficient with the inbuilt regs ( which contrary to popular belief is the problem not the alt design) so you would want about 5 HP to make 1500W. I can drive 2 flat out and my 6HP lister is really working at that.
I would like to know how to wire in an external reg on these things for that reason and so I could pair them up for 24V output. On these, the regs are soldered to the rectifiers which are attached to the stator outputs. The reg is integral to the brushes so not sure how to bypass them
(http://www.3si.org/forum/attachments/f35/239065d1482662502-alternator-ground-problem-ground-stud-broken-3saltstud.jpg)
Anyway, As a simple alt, these things are awesome and if your boy is going to be around it, add the maybe irrelevant bot of safety of having no fan although the belt is still a concern.
I mashed a finger and split the bone in 2 places when I got clipped by the fan on an alt. Belt wasn't a problem but that fan sure gave me some grief. Of course the Quack I went to and said it was just cut and bruised because I could still move it didn't help things. Time I figured something wasn't right a month later and went to a real doc whom xrayed it, there was nothing they could do. Said it had healed itself probably better than what they would have been able to do if they operated at the time. Doc thought I was the toughest guy He'd ever met to put up with it for month. Didn't have the heart to tell him it hurt like hell and I was just too stupid to know any better.
These Mitsubishi alts should be popular and cheap as well. If you can break one, let me know how because I haven't been able to so far! :0)
Glort, the only way I know of to use an external regulator with the integral brush/regulator type design is to butcher the regulator, and bring out the brush leads on some high temp silicone wire. I did this for my '85 MB 300D alternator. How hard this is depends on the regulator/brush assembly design, it was a job for a dremel type carbide burr on mine.
One our members developed a state of the art digital regulator for 12/24v regulation. BobG already showed us years ago that 12V alternators will efficiently put out 24V with the appropriate regulator.
Very good summery recommedation glort.
BruceM is correct any of these internal regulated units can be gutted bypassed to an external regulator.
From your pictures I'd say yours would be done by de-soldering the six shown points on the back of the regulator/brush holder and just lifting the regulator off. Then test-light VOM track down the six terminal point to their curcuits. Probably both bushes would be insulated then with the capability to "A" circuit control.
Back in the mid-last century i had a commercially made up loggers charging system made up of a made-in California, McCullough 2-stroke (chainsaw-power head) and a Motorola small case alternator. This unit had both an external 12VDC and 24 VDC voltage regulator. Switchable depending on what out in the pucker brush piece of equipment needed starting batteris charged. Same mixed fuel as they used in their saws. Fire up the charger. Set to the proper voltage regulator and walk-away to do paying work listening for it to run out of fuel. Equipment crank to start then? No. 'Nother tank of gas-mix, and go again.
Purposed designed 24 alts, in the same case size, have smaller wire to limit the Amps made; then heat made, to prevent overheating the units.
The Delco SI series once turned on can only be turned off by taken back to zero RPM! Just like the old DC generator/control regulator systems.
Why Delco/Delpi later went off the SI system (internal field powering diodes) to have the ability to while spinning, turn-off, load-shed the alternator loading.
Small engine generating it is nice to be able to NOT be engine loading until warmed up enough for stable running.
tree-farmer Steve Unruh
Thanks for the input gents.
I did read somewhere of someone saying with these that he just drilled a 1/2" hole right through the reg then tapped a wire on the brushes and used an external reg that way. I'd like to try and do it more " Professionally"
but whatever works.......
Have to try and find an economical reg that can do 12 or 24V and give it a go. I'd love to get a big leece alt but they are impractically expensive here and while much cheaper in the states, the postage charge is nothing short of an insulting Joke. Not sure wether it's just online sellers taking the piss or US postage is 10X more exy than anywhere else in the world.
If I could couple a pair of the mitsubishi alts together, that would be probably just as good and maybe with the lister I could do 3. Probably do 4 with little trouble with my 12 Hp Lombardini. Series/ parallel would make for some decent amps, 160@24V.
Steve, Years ago I coupled an alt to a little China diesel engine to run some inverters for some work I was doing in the middle of paddocks. I bought a cheap 2 wheeled trolley, had heavy long leads on it and a Digital volt meter so it was all set up and easy to move. I had the batteries mounted in the trailer and could move the gen set away a bit so it was quieter and also had a couple of 12V fog lights on the trolley on telescoping tent poles so it could also illuminate things when we packed up then just be rolled into the trailer. Had a panel to switch the alt in and out and direct couple the field and a small 240V inverter mounted on it as well. Was a nice setup that was very handy and worked well for what I was doing.
Judgemental, disapproving of everything Brother in law came to visit one day when I as cleaning trailer and was going on about what a waste of time and why not buy a generator and be done with it and.....Blah Blah.
Told him this way I could run low loads off batteries for a while without having to run gen the whole time and money was tight, I had everything I needed bar the $12 I spent on the belt and $25 on the hand trolley and it had been working fine. Usual snort of disapproval and inference I was an idiot.
Sister in law and Mrs talked for a while and when it was time to leave, BIL discovers he has left headlights on in car which now won't start. Everyone questions why he had them on in the first place on a fine day which nicely rubs in some more salt.
Can't jump the thing because it's in the driveway and can't turn cars around. He asks about removing battery from wifes car. No good I say, wrong terminals and too much stuffing round, I'll do it the easy way.
I walk up the back, get 12V gen set, and put it on flat battery while he's mumbling it better not blow anything electrical in the car. I shake my head. Sis asks how long will this take? I said about 3 Min. BIL snorts again. After short conversation I tell BIL to start car. He says what will that do? I said start the thing so you can get out of here or course. I had The field going back to full 12V so it was pumping the full 120A that alt did.
He hits the key, thing turns at full cranking speed and fires straight up. I drop Bonnet, take engine away and don't even get thanks as they drive off.
Typical.
But geez having the last laugh and saving his indignant arse was something I still get satisfaction out of remembering.
About a year or so later he has to eat humble pie again. Batteries on his battle ship of a boat have gone flat because someone ( like him) forgot to plug the thing to shore power and fridge has drained start and house batteries because the isolator is wired wrong. He wants to take it out with friends and will take a day for the onboard charger to get the things up to start. Ask's how long my charger would take to get these batteries up to start the the big diesels. I ask battery size, of course he has no idea so assuming they are n200's I say 30 min to hour. He asks if He can borrow charger. I say sure. Next he needs me to bring it to marina because won't fit in his antidote for a mid life crisis sports car toy.
I take it down, make him crawl in the claustrophobic engine room and tell him how to disconnect batteries then reconnect charger. Fire it up, it's working hard but each battery seems to come well up in 15 Min. Meanwhile there are a bunch of friends he was going out with all standing round and saying what a great setup this is and asking lots of questions about it. Reconnect batteries, Thing fires up no probs. Onlookers are really impressed saying they thought he was out of action for the day. Bil makes some comment about all the wires and weight to which someone says, "Well it just saved you from spending a day here instead of out on the water didn't it , I wouldn't care what it looks like if it did that for me." So satisfying to hear...... :0)
Still treats me and the other BIL who is 10X smarter than indignant BIL and I put together like morons, but 2nd BIL and I just laugh with one another now and make him look foolish often as possible.
Which isn't hard.
The entire project has morphed into a monster. ::) What started as a proof of concept leaning (fun) project for my son has turned into a whole house UPS in a matter of days. Sometimes I really hate the internet :D .
Part of the reason for the morph was a real eye opener this past week with the rather robust wind storm in New England. Now, I now longer live in the NE, however my tenant (also a good friend that is baby sitting all my toys up north) and the rest of my family lives up there as well.
Both my friend who is living at my house and one of my brothers has been without power since early Tuesday morning and are still without out power. Estimated time to power is turned back on is Saturday.
My tenant has full use of my http://www.microcogen.info/index.php?topic=2837.0 (http://www.microcogen.info/index.php?topic=2837.0) Kubota D905 generator. It has worked flawlessly but as is often the case was only needed for short periods to bring the Freezers and Fridge back down to temp, run the pump in the well for water and meal times (gas range but microwave etc) the rest of the time the generator would be spinning away at very little load time. Here we have a 8kw generator spinning away for only a fraction of a KW. Wasted fuel.
Recently here in the SE we had aa 24h power outage and I used my small https://www.championpowerequipment.com/product/100158-3100-watt-inverter/ (https://www.championpowerequipment.com/product/100158-3100-watt-inverter/) inverter generator rated 2800w/3100w surge.
It ran the house fine for the basic needs, no central AC but ran the micorwave, coffee maker for the wife etc.
Still found myself running it for short periods and turning it off because it was just idling away putting out 700w or so for the basics. Night time rolled around and it was lights out, turned it off and went pitch black. And to bed we went. I don't sleep well with the generator running at night.
Thought to myself it would be nice to have a giant UPS for the house. But didn't give much more thought to it. Then fast forward to this "Proof of concept" project and the gears have gone from 1st to 5th in a matter of days.
Have decided to build a 12v UPS for the house for when the house is consuming little power which is "MOST" of the time during an outage.
Here is my stab at a basic system to see what you guys think.
This will be in line with my 2800w generator, when the generator gets shut off the UPS will take over.
4 225ah 6v golf cart batteries wired in parallel/series. Giving me 12v 450AH of capacity, of which 50% is usable. So effectively giving me 6h of run time with an average ~400w load. More then enough to get me through the night.
Aims 12v 2500w inverter with built in xfer switch and charger.
http://www.aimscorp.net/2500-watt-low-frequency-pure-sine-inverter-charger-12-vdc-to-120-vac.html
(http://www.aimscorp.net/images/P/picoglf25w12v120almain.jpg)
Gen will feed into inverter via 30a 120v breaker once the generator is shut down the Aims will take over with automatic 15 ms xfer.
Thoughts on voltage: 12/24/48
Read a good rule of thumb is:
1000w or less 12v
2000w 24v
3000w+ 48v
I really tried to convince my self to go to 48v or 24v. I could do 24v with the same batteries but I decided to stick with the 12v simply because it's common and most of the time this would see sub 1kw
Charging, I can still use the engine my son and I rebuilt to charge the battery bank in the event we need to use the power from the genny for house loads
I have a few huge 400a 24v alternators that can be used as a charger I also have several 24 pole PMG generators like those used here http://www.microcogen.info/index.php?topic=2961.0 (http://www.microcogen.info/index.php?topic=2961.0) by SPSInc. for 48v.
12v seemed KISS for a first time around the rodeo.
You guys have A LOT more experience with these type of systems then I do, so I thought I would run it by you first.
If you have to go 4 batteries for capacity, you'll get better service life and capacity out of them by going 24V. Half the current draw so lower losses in the battery and wiring to inverter, and less equalization charging and water added. If you're sticking to 12V for other reasons...then find some larger capacity batteries or individual 2v cells and avoid parallel batteries.
I'd also go 24V.
If you have to run any length of DC wire it can be half the gauge to start with. You are going to be looking at near 200A with 2500W load with 12V. Switches and connectors are pricey and hard to get at that sort of rating. 100A is much cheaper and easier to get.
Other thing is seeing you are going whole hog on this, Why not add some solar panels to the batteries? Normal used roof panels can be had easy and cheap where as 12V Panels here at least are firstly relatively low wattage and secondly stupid expensive on a watt for watt basis with even new roof type panels.
I run a cheap 30 A PWM controller with a bunch of domestic rooftop panels for months and it worked fine with 24V even though the load voltage of the panels as supposed to be 34 and open circuit was 42.
When I tried putting the " 24V" panels through the controller to a 12V battery, all the magic smoke came out as well as a lot of unpleasant sounds.
A few solar panels could mean the only time you ever have to fire the genny was for cooking or larger loads. Few solar panels would be great for those light loads and might supply them completely depending on how many you have which would prevent any cycling of your batteries and extend their life significantly. Would only take 4x 250W panels to supply 1/3rd of your generators capacity and you could probably run the coffee maker and the Microwave individually without the genny and then let it bring the battery's back up to full charge in between uses.
Also be aware that a genny will have to run a LONG time to fully, 100% charge your batteries because the more charge, the greater the charging fall off. With with the solar it would float them at 100% till you used them and then work to bring them right back to 100% and keep them there automatically, silently and fuel free. They may also be working one topping the night drain up in the morning before you are out of the house to fire the genny. Quicker you get that power back in the batteries the better!.
Good point by Glort on PV to finish charge the batteries and save a lot of generator time and noise, plus a big boost in battery life.
For those reasons I always let my PV system finish charging the batteries even on dark winter days...the generator does only the bulk charge.
Thanks for the input fellas.
I was doing some digging around for some ideas and came across this post in a solar forum that I thought was interesting.
http://forum.solar-electric.com/discussion/352587/battery-advice-and-recommendation
This fellow had the same idea I was thinking of doing but he did it 8 years ago. Never used his batteries and now they're dead. In this thread there was a reply that I thought was pretty reasonable:
"Here's a suggestion, get yourself a grid supported inverter charger which has load shaving capabilities, run critical loads off the inverter, during the day use your excess solar production to support or partially support the loads since the inverter would have AC pass through capabilities. In the evening when peak billing occurs, program the inverter to allow battery power to support the grid, when peak billing terminats, grid power will recharge the battery at lower rates. In such a configuration you would actually be getting some payback from the batteries rather than them just sitting there waiting for an outage, of course they will still be available in such an event. Having a strictly backup system has little return and the expenditure for the batteries goes, for the most part, waisted, which is a shame, expanding your array would save you energy during the day, by offsetting grid consumption. Here is an example of a unit which will work for such an application, others are available, Magnum, Outback come to mind but I'm not personally familiar with them, although I understand they're excellent products. https://www.solar-electric.com/schneider-electric-sw-conext-inverter-2524-120.html
Of course I'm making the assumption there is peak billing by including load shaving, but advantage can still be achieved without, in the form of grid support, during the day. Some ideas to ponder.
One could go further by selling back to the grid during the day, if loads are light, but that's a little more involved and of course if it is permitted by the utility."
The idea of load shedding has merit and something that I might consider in the future. My utility has very low off peak rates of .047/kwh , peak is significantly higher. Right now I'm renting a house, but will buy/build within the next 12 months.
However I can start building a system now.
Reason I went with the Aims inverter was it did what I wanted at a reasonable cost ~$500 without a lot of extra bells and whistles. It got my feet wet in the world of inverters and batteries maint. As soon as I started looking at 24v the price went 2x or 2x quickly. That being said I certainly didn't get as far into building the system on paper to include wires and ends so thanks for that tidbit glort.
Bruce can you elaborate on the "big boost in battery life" by allowing the PV to do the finish absorption stage of charging.
Perhaps it's wise to not look for an inverter to do it all but piece it together? In general I like individual components when I build things, however all in one solutions like this Samlex are compelling yet again nealry 3x the price of the aims
https://www.invertersupply.com/index.php?main_page=index&cPath=1304_390_405
Specific samlex:
https://www.invertersupply.com/index.php?main_page=product_info&cPath=1304_390_405&products_id=16982
Appreciate the advice guys.
to save $ by using expensive batteries for load shaving, requires awfully high electric rates. Higher as in 2$ KWh, in order to break even on batteries.
But you do end up with the biggest UPS on the block.
do the math for your rates and battery costs/lifetime, before you buy.
Quote from: mike90045 on November 05, 2017, 11:21:33 AM
to save $ by using expensive batteries for load shaving, requires awfully high electric rates. Higher as in 2$ KWh, in order to break even on batteries.
But you do end up with the biggest UPS on the block.
do the math for your rates and battery costs/lifetime, before you buy.
No doubt.
The load shaving idea isn't intended to replace the battery cost, more to mitigate them. As in the link provided above, the gentleman built a UPS with 16 x Trojan T105 batteries and they never got used.
I'm in the SE now, and we lost power during Irma, although only for a few hours, and the year before that, Mathew. My thought is to possible kill two birds with one stone. I have not run the numbers yet but I certainly can for a purely economical standpoint.
For that matter a generator would suffice. The original purpose of the system was to run the basics in the house for a short period of time, say 6 hours.
Regarding my electric pricing structure, this is how it works - and it's rather unique as far as I can tell.
QuoteThere are THREE main categories of cost incurred by our system by residential and commercial members:
1. Account charge Residential 80¢/day Commercial $1.10/day
This recovers the cost of making service available to each member.
2. Energy charge Residential 4.7¢/kWh Commercial 5.7¢/kWh
This is the energy portion of the power cost.
3. On-Peak charge Residential $12/kW Commercial $14.75/kW
This is the rate for the highest ONE hour of electric use during the On-Peak time frame of the billing period.
If you read up on lead acid battery service and lifespan, you'll see that sulfation is a common cause of early cell death. It happens when batteries are not brought up to 100% of charge and held there long enough to break down the sulfation that always occurs. The longer the battery sits at NOT full charge, the more sulfation you get. Equalization charging (slightly elevated voltage for 4-5 hours) is used to combat this problem, but it uses power(generator or PV), water and eats the positive plates so you don't want to do it more than necessary.
With a PV charger added, the batteries will be kept fully charged at the float voltage most of the time, and thus can have a lifespan closer to the float service life (except when cycled at 50% or less for power outages) ...often twice the normal service life.
Bruce. Yes I read up at battery university. Thank you for the clarification.
The gentleman that built his UPS said the following:
The batteries never got used or cycled as the whole system is only intend for back up power in the event of an natural disaster / earthquake or grid shut down etc.
I maintained the old batteries for the past 8 years, trickle charged them, equalized them when needed and filled them with distilled water when needed.
They still look like new .. but the batteries aren't taking or maintaining a charge anymore. So it's time to replace them.
That is why the thought of load shedding was considered he got zero use out of them, and appeared to maintain them correctly and never got a chance to use them. AGM batteries are an other option. Appear to be about twice the cost of FLA.
Quote from: RJ on November 05, 2017, 01:10:56 PM
3. On-Peak charge Residential $12/kW Commercial $14.75/kW
This is the rate for the highest ONE hour of electric use during the On-Peak time frame of the billing period.
[/quote]
$12 a KW????????????
That would have to be unique all right!
Is that a typo or something?
To me that says you are going to get charged $12 per day, anytime you use power in the peak period?
Can't be right, would you care to explain?
As for the rest of your rates, 4.7C, There is no possible way on this gods green earth you are going to save money on that rate! The cost of the equipment amortized over it's life wouldn't come near that alone.
I got to say, it seems like you are waaaay getting carried away with this. From what I understand you are wanting to have something to see you through occasional outages. You are now talking about all sorts of equipment that will cost big bux and net you a negative return with setting up to offset your power bill at that rate.
I may not be understanding everything correctly but but it seems to me you are going headlong into an expensive, complicated system that will require decent amounts of maintence to have any decent working life.
For your objectives, seems to me all you need is a generator worth a couple of grand and the rest you'd be better off putting into a solar panel system to offset your daily usage.
Batteries, chargers, inverters, panels, controllers, wiring, electrician fees..... It really does seem like you are building a monster that is going to cause you more grief than good.
If you want to go offgrid, then do it and properly. If you want a backup for the grid, seems to me you are going waay overboard and your money could be much better spent on things you and your family will get a lot greater benefit and pleasure out of.
:0)
Glort, no not a typo. I copied pasted it directly from the COOP site. http://www.mcecoop.com/content/rate-structure
The way it works is the electric company take the highest ONE hour load you have during that peak hours for the month. So say you have peak usage of 5 kwh during that peak window in the month of December, you get billed at the rate $12/kwh or $60 plus you normal kwh rate. For simplicity sake say I have 500 kw used in a month. And my max one hour usage during peak hours is 5 kwh. ((500*.047) + (5*12)). (23.50)+(60) = $83.50 for the raw electricity minus any fees. It certainly behooves one to cut usage during peak hours. As of now I have my water heater on a timer and turn off all my AC units.
I agree on complexity. I still want to build a UPS, however I think I will be best served to keep it simple, perhaps instead of 12v go to 24v as you and bruce suggested and run 4 golf cart batteries in series. Interstate 6v golf cart batteries at my local costco are $78 plus tax and $2 battery fee.
That sure is a strange peak billing scheme. You only get billed extra for your highest hour's use...not extra for the total power you use during peak hours.
Billing for demand is common on commercial electric rate tarrifs.
It still seems like it might actually be pretty cheap compared to what we pay here.
What is the peak period?
It would certainly promote changing to gas hot water, clothes dryer, and stove.
I like the sales pitch about how you have a choice...this is not really true for a working class family with both parents working and renting. There aren't enough hours in the day for them to shift to!
Alright settled on a 24v system. with 4x6v golf cart batteries @225 AH. Was thinking 1500w pure sign inverter. Would like to get a good quality unit, and suggestions?
Looked at the Samlex 1500w here:
https://www.invertersupply.com/index.php?main_page=product_info&cPath=1304_390_405&products_id=2137
QuoteHigh efficiency
Can be hard wired
Temperature controlled cooling fan-reduces energy consumption
Low interference
Wide operating DC input range: 21.4 - 33.0 VDC
Commercial grade design suitable for heavy duty loads, long periods of continuous operation & for emergency back up
UPC-Universal Protection Circuit: low voltage, over voltage, over temperature, over load and short circuit
Low idle power draw
Dual GFCI protected AC outlets
Optional remote control (sold separately): Model RC-200
Safety certified to UL standards, FCC compliant
Price $460 ~3.26/w
Same inverter x 2000w is $705 ~2.83/w
At a point more money then that it might be worth looking into the combo units for future upgrade??
At some point I would like to tie solar into it, perhaps 3 or 4 250w panels. That will be added later, perhaps in the spring when there is more sun to deal with. Plus it will give me some time to find some panels locally on CL
Will need to select a 24v alternator.
The ones I have are over kill for the size of the battery bank.
Was thinking of getting perhaps a sterling alternator regulator to give me 4 stage charging (3)
http://www.sterling-power-usa.com/sterlingpoweradvancedalternatorregulators.aspx
Or perhaps pull the regulator out of the alternator and feed it into a solar MPPT charger such as this?
https://www.invertersupply.com/index.php?main_page=product_info&cPath=1304_258_260&products_id=1030
That way when I go solar I can dual purpose it, when the sun isn't shining I can disconnect the solar and hook up the car alternator to charge the bank.
The problem without having solar you have to run the internal combustion engine a long long time for the final 20% of charging of the batteries. If the batteries don't reach 100% full charge several times a week they start to sulfate and then you lose capacity and the batteries can be ruined within a couple of months.
Quote from: RJ on November 08, 2017, 03:19:52 PM
Or perhaps pull the regulator out of the alternator and feed it into a solar MPPT charger such as this?
https://www.invertersupply.com/index.php?main_page=product_info&cPath=1304_258_260&products_id=1030
That way when I go solar I can dual purpose it, when the sun isn't shining I can disconnect the solar and hook up the car alternator to charge the bank.
Right now the site is down so I can't see what you are talking about. As far as taking the reg out of the alternator, I'm guessing that you may be trying to couple it to a grid tie, High volt input inverter which kicks in at 90-120V? If not and it's 24V inverter, much the same thing.
I have tried MPPT inverters with alts and it was not successful for me and I doubt it would be without some sort of electronic regulation additionally.
What happens is an MPPT tries to find the sweet spot of the alt just like it does with panels. It will up and down the amps to try and find where the most watts are. That's what they are designed to do, keep testing the water as it were.
What happens on an engine driven alt is the inverter will pull to it's max capacity which pulls the engine down. I was using a capeable engine for the alt which would turn it at full output constantly with a reasonable margin. IE, it wasn't flat out, maybe 75-80%, but the MPPT's seem pretty sensitive and as soon as the watts drop which will happen with a mechanical governor, the Mppt lightens up and the revs and volts pick up. Seeing there is now more apparent power, The mppt will increase the load again trying to pull the Volts back to it's nominal sweet spot, power drops, inverter backs off and you go into this endless seesaw effect.
I tried caps and base loads and all sorts of things and I could not get it to change which is the logical outcome given the way teh MPPT is designed to work.
I tried the same thing with a petrol generator with AVR and a rectified output, same thing. MPPT inverter had it hunting all over the place and the inverter would drop out in a few seconds due to the variation which it sensed as a fualt condition.
The only ( simple ) way I could see it working would be to have an alt capeable of say 2000W and the inverter only rated to 1500 say. The engine would be the bigger the better with heavy flywheels for better reactive power. ( Less slowing when a heavy load hits) The alt I had was over the Mppt's capability by safe margin and even though the engine could carry full load of the alt, it doesn't take much to get SOME variation and the mppt seemed sensitive to this. Even with solar panels in clear midday sun, I can still see endless variation of at least a 50V range all the time. Usualy not as much as 50V but will certainly move that much regularly but NEVER constant on an output of around 2KW and well over driven on the panel side as well.
If you are talking about a 24V alt and a suitable MPPT inverter going to the batteries, can't see it being any different. MPPT is always going to be ramping up and down increasing the load and backing off and being electronic will be faster than an engine can respond be it mechanically or electronically governed. You'd want a 3208 Cat or a 6V53 jimmy driving a 5Kw alt to be stable enough I reckon, something 100X overkill.
MPPT is a waste for this setup. If you are going for a grid connected unit you probably don't have a choice as all solar inverters I have heard of are MPPT. What you really want in this setup is actually a PWM type controller . One that you can dial up the output and if the input is constant, so will the output without hunting around. MPPT is only really needed for solar panels that may get shaded or clouds etc. where the PWM reduction would be unlikely to be the most efficient. When you have something that going to produce the same power at the same speed for the same load, PWM is every bit as efficient and in this case, most likely the difference between workable and not.
I would expect if you took the reg out of an alt with a Mppt controller attached, it would be even more unworkable. The power curve would be even more all over the shop and the Mppt would go nuts as would the engine govenor trying to keep up with the load that was all over the place. The Govenors simply aren't designed for that and if you were using a small, lightweight petrol engine...... Pffft! Forget it!
I tried that ( at length) with a big electric motor converted to a generator. Set up a C2C conversion with capacitors and 3 phase 100a rectifier to turn the 3 phase supply to single phase and ran that into the grid tie solar inverter.
With a 6HP diesel, even with the 5.5Kw engine that weighed 50Kg, the variation was too much and the inverter would trip out on low input as it dragged the diesel right down.
Next bright idea was to use a bigger diesel, a substantial 12HP that has a lot of grunt and about 3 times oversized for the job. First I set up to get a stable voltage with a mid range load. Revs vary output on this sort of setup. That done, I put on the inverter. It kicked in, fairly gently at first then sensing volts were still in range it ramped up. pretty fast. Even teh big engine with teh big IMAG couldn't keep up, I watched the volts fall on the multimeter then the inverter let go and the volts shot up..... way over the inverters rating ( Way over!) and must have defeated its protection and cooked it. Also lucky it didn't blow the shit out of the 400V rated caps in my face and arc out when my multi-meter literally blew itself off the floor as I saw the last read out at 1280V.
I'm not sure the way around this for you. If you can find a PWM inverter, which I doubt, you may be OK. Other than that, I think you are going to have to go for a setup for the engine generator and another for solar.
Don't mean to sound a killjoy or a bitch but to me this is getting way over the top. Sounds like you have a lot more money and earn a load better than I do but I can't see the economics of it.
You want backup power, fine, go get a Genny and a transfer switch and you are good.
You want to shave that $12 Kw fee every month, I get it. I would too.
Thing is what I'm seeing here is you are going to spend FAR more than you could ever recoup on that. If your high is $60, how many month is your investment and everything else going to take to pay off?
The answer is more than the life of the batteries and most likley everything else as well. And don't forget, those batteries are going to be good for about 500W for 4 hours. If your peak is 4 hours which I'm guessing is a minimum, you are going to save yourself $6 a month. If it's 2 hours and you are backfeeding, every night/ day mind you cause they get you on the highest one...... you will save $12.... a month.
No one likes to fart about with money saving schemes more that I do. Been running veg oil in my vehicle 15 years, back lawn is half covered with solar panels I have been testing and getting ready to put up, have heated the house with veg oil burners and so it goes BUT...... They do save me money. real money. This is a cost. A big one.
If you are happy with that for the price of entertainment/ hobby, that's more than fine but if you are under any illusion it's going to save you money...... it's not. Especially at 4.7 c kwh regardless of the $12 Charge.
If I paid that instead of 30C kwh flat, I woudn't need to screw around with panels.
If you are doing it for blackout protection, as I said, generator and transfer switch and spoil the boy with something nice with the left over money or take the family on a holiday or even a nice weekend away.
If you have more money than you need, then enjoy it because you have well earned it! :0)
Thanks for the input Glort, very much appreciated. It sounds like you have certainly gone though it and then some.
Good info on the alternator trial and errors.
I found a good deal on a Cotek SK2500-124 for $600 new.
These are discontinued and the outfit I contacted was looking to be rid of their last one.
Here is the info from inverter supply:
https://www.invertersupply.com/media/data/ST2500.pdf
The unit has a 30a built in xfer switch and is designed to be hard wired in.
It's a well built unit coming in at 26lbs made in Taiwan.
the batteries will cost me ~$400 bucks.
I figure misc battery hardware, cable fuses, etc $200
So for the basic UPS setup $1200 bucks.
Do you have an experience feeding a solar MPPT charger with a power supply, say a 1000w 48v unit which I happen to have handy.
I will keep my eyes open for a few 250 panels to put in the back yard.
As of now I'm looking at this as a simple emergency backup that will run the basics in the house at night (alarm system, fridge, etc) while the generator is off.
Quote from: RJ on November 10, 2017, 09:09:47 AM
Do you have an experience feeding a solar MPPT charger with a power supply, say a 1000w 48v unit which I happen to have handy.
For those wondering it looks like it can at least be done with a morningstar MPPT controller:
http://support.morningstarcorp.com/faq/
Quote from: RJ on November 10, 2017, 09:09:47 AM
Do you have an experience feeding a solar MPPT charger with a power supply, say a 1000w 48v unit which I happen to have handy.
No, never had thought or occasion to do that although I can't see why it would not work as long as the output from the power supply was well rectified.
Output is not going to bounce around and the inverter should be able to find it's sweetspot and settle. If you have something like a forklift battery charger will be fine.
How you thinking of setting it up? Letting it run off AC at night and then the panels supply the power during the day so the inverter always has an input?
Doing that with an LED light bar ATM for raising seedlings. Fed by a battery charger and a Solar panel. At night the charger supplys current. During the day the output from the panel surpasses the chargers output and the current from the charger drops to zero. Morning and afternoon the panel makes part of the current and the charger the other.
Quote from: RJ on November 10, 2017, 09:09:47 AM
Do you have an experience feeding a solar MPPT charger with a power supply, say a 1000w 48v unit which I happen to have handy.
Morningstar MPPT works to downconvert a battery. Other brands are unknown, and I would be cautious, you may need a ballast resistor to make it work. They generally work because they think they are dealing with a current limited PV panel and rely on raising or lowering the MPPT input voltage to regulate the input power. That may not work with a battery or power supply as a substitute for PV panel
Thank you Mike. So far morning star is the only one that I have found that will confirm this will work.
I have several JFS1000-48 power supplies.
http://us.tdk-lambda.com/ftp/manuals/jfs1000_man.pdf
Adjustable from 36-56v
Coupled with a Tri-Starr MPPT-60 controller it would work well as a battery charger/PV charge controller.
41 amps at 24v is a little high for a 225ah bank. I can also use this to charge off my inverter generator in a pinch.
C/8 charge rate ~ 30 amps
fwiw
battery sulfation is a natural process that happens any time a battery is discharged, sulfate will form on the plates
this sulfation will be reversed during the next charging cycle,
the problem for batteries is this, the allowance of the normal soft sulfate to harden.
generally speaking charging to 100% once every week or 10 days, will revert the sulfate before is starts to crystallize and harden. there is much written on this over the last decade or so, in various forums and on various battery manufactures websites. this is where the "50-80" regime comes from.
charging a battery from 50-80% state of charge allows for a relatively highly effiicient charge, because you can dump a lot of amps into a battery within this window, without excess heating or loss of water.... once you hit 80% and charge up from there you must lower the charge rate and monitor things, to keep temperatures in check, and reduce water usage/loss... the efficiency drops precipitously over 80% the closer you get to full charge.
many systems have successfully used the 50-80 regime, topping off to 100% once every week to 10 days, and then equalized once a month or even longer in some cases.
unless one has a rather large installed capacity of solar/pv panels, or is willing to run long hours with a genset, trying to charge to 100% several times a week over time will be much more costly over the long haul... and it is likely the batteries will not live as long either.
around here, even if i had massive amounts of panels, i can't figure how i could recharge to 100% several times per week, not unless i planned on long generator hours at very low loading?
then again, it has been a very long time since i was part of this debate.
having been in politics for 2.5 years now, i can tell you this...
it has done nothing for my mental capacity! which makes me wonder why there
are so many idiots in DC!
but i digress
hey i still know how to do that! :)
bob g
Bobg's statement of the characteristic inefficiency of lead acid batteries for the last 20% of charge is right on the mark and very well documented by Sandia labs, among others. (AGM batteries are significantly better efficiency but still less so the last 20% of charge.) By the last 5% of charge you are typically at 45-50% efficiency. This is very important to be aware of if running a generator to charge with.
But it is not an issue for PV charging since this is at a much reduced current.
I would argue that the general statement about the need for an excessive size PV array to accommodate full charging is out of date and may confuse newbies. With PV costs now around $0.33 per watt, excess capacity for completing bulk charging earlier in the day should be the rule, not the exception. Check out prices at sunelect.com. Secondly, in most climates, if you have even barely adequate PV to meet typical winter charging needs, and seasonal tilt capability, you already have grossly excessive capacity for the rest of the year.
Topping off the batteries with a good 3 stage controller takes little PV power away from daytime loads and does not increase water use. Most days, your batteries should be in float by noon. I am only adding a bit over 1 gallon of water every 2 years and my batteries are fully charged about 360 days a year.
But you must be smart about your particular batteries and what it takes to extend their service life. If your bulk charge rate is too high for the battery size and type, you will see excessive water use and plate erosion. Where a higher charge rate is necessary, larger capacity batteries at lower DOD or AGMs might serve better.
Thank you Bob and Bruce.
Bruce is this the site you are referring to?
http://sunelec.com/home/ (http://sunelec.com/home/)
Yes. I used to shop at Solarblvd.com but they seem to be in a slump for name brand panels, and I don't trust their various store brands having had problems with them not meeting even 60% of spec.
BobG had a much more detailed explaination on the 50/80 charge scheme on the Lister forum and there he cleared up the issue of using PV.
For racks, I like ground mounted, seasonal tilt capable panels unless risk of theft or space forces roof mounting.
A scale drawing of my latest (5) 250/300W panel rack design is attached. You could cut back on steel sizes if not in a high wind areas like I am. One man could handle the seasonal change. 1" EMT with smashed flat ends are the braces.
The rest is welded up on site. This should be roughly $300 in steel.
Quote from: BruceM on November 15, 2017, 03:16:34 PM
Yes. I used to shop at Solarblvd.com but they seem to be in a slump for name brand panels, and I don't trust their various store brands having had problems with them not meeting even 60% of spec.
BobG had a much more detailed explaination on the 50/80 charge scheme on the Lister forum and there he cleared up the issue of using PV.
For racks, I like ground mounted, seasonal tilt capable panels unless risk of theft or space forces roof mounting.
A scale drawing of my latest (5) 250/300W panel rack design is attached. You could cut back on steel sizes if not in a high wind areas like I am. One man could handle the seasonal change. 1" EMT with smashed flat ends are the braces.
The rest is welded up on site. This should be roughly $300 in steel.
OKay just waned to make sure I had the correct site. I don't see any mono panels listed, but gosh some of those prices are fantastic. He also a great price on the schneider SW4048 at $1400