single wire low RPM cut in. Suggestions...

[RJ]

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.

[Tom Reed]

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.

[RJ]

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

[glort]

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.

[XYZER]

Or charge his electric scooter!

[Tom Reed]

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.

[RJ]

looks like a 10si will do the job. Thank you fella's

[SteveU.]

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

[RJ]

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

[SteveU.]

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

[glort]

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





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)

[BruceM]

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. 

[SteveU.]

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

[glort]

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.

[RJ]

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   .

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 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/ 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




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 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.