A Different Perspective on Automotive Alternator Direct DC Charging

[OFFGriddnPat]

We must be measuring amps differently. You guys must be talking about taking an amp reading off the alt, which would be 95 amps in 12 volts, which would read from my 24 volt wired system 190 amps. 95 amps here would put that little 6.5 in the dirt.

There's no way a 6.5hp engine will handle 2 alternators, unless the load was extremely light on both alts- some where around 15-20 amps for a 24v system. The 16hp yes, and you would be puttin' a good grunt load on it.

Something I should have mentioned yesterday- L16 batteries are NOT like your car or deep cycle marine batteries. They like to be boiled, and equalized fairly often. That's the key to their longevity. They are not prone to "plate corrosion" like what you may be used to.

When I speak of amps on this thread I stated it's referenced off of my 24V solar system via Trimetric.  

Example:

I have 1kw of solar panels on the house. 10 SR100 seimens that are rated a little over 5 amps each.  If my system was wired for 12V, the Trimetric (wired off the shunt) would show about 50 amps full sun.
Since my I have a 24V system, my Trimetric reads 25 amps full sun. Actually peak off of them is 29 amps.

SO when I say my DC alt chargers are putting out 95 amps by running the 6.5hp and the 16hp together, (24V system reference) on my Trimetric meter- if my battery bank were wired in 12 volts it would read 190 amps.  If my battery bank and inverter was wired for 48 volts, it would read 47.5 amps.

Hence when I say my 6.5hp DC alt charger is putting out 40 amps, you may be thinking 40 amps in 12V. No- it would be 80 amps in 12V wired solar system.

I don't know if I'm being clear here, but that is what I mean when I reference a 24V wired system- 24V inverter and batt bank.

[mobile_bob]

Pat

i for one followed what you stated from the start

90amps on a 24 volt system, ok so everyone is on the same page

on my system i can pull about 8kwatts with 2.88 kwatts (28.8vdc @ 100amps) from one 555 alternator and still draw
nearly 5kwatts from the ST7.5 head both running at the same time, or

i can pull near the full 7.5 from the ST head running alone with the 555 alternator shut down.

either way the fuel used works out to very close to 10kw/hrs per gallon consumed.

i can also shut down the ST head, reduce the engine speed to 1300rpm and decrease the fuel consumption another 5% running
the 555 at the same ouput of 2.88 kwatts (28.8vdc @ 100amps)

i cannot get even close with reostat control, because as the batteries recharge the voltage will climb and things start to get hot
in a hurry, unless i am will to keep a fairly close eye on things and adjust as needed.

the balmar (and hehr controllers i test with) can make those fine adjustments thousands of times per second, and keep the voltage
spot on what i am asking for, maintain the specific load as seen by the engine, and also tailor the charge as things warm up which protects
the alternator and the battery bank.

also once i have the refer compressor system working, when the clutch kicks in i can also use the same signal source to trigger the balmar to
50% output so that i have additional available hp to drive the compressor with.  yes i could do this by hand, but the balmar does it seamlessly.

these controllers are surprisingly robust, reliable and trouble free,  if one smokes it is because i hooked it up wrong.

for me it makes perfect sense, and i just can't accomplish all the things i want done, without the use of a programmable controller.

i just don't want to manage things or babysit a system when for a couple hundred bucks a small box of electronics can and does do a much
better job than me.

in closing, yes i will have a small engine drive alternator that is reostat controlled, however its use will be relegated to quick charging a car/truck battery for the most part and used as a backup to the main system should something happen that takes it offline for a while.

for me, i see at least 3 differing gensets, a small, a medium and a large one, that way i can match the generator to the loads prevalent during
specific times of the year.

bob g

[Lloyd]

OK- I don't follow you guys. I'm a little slow at times, plus I have a wall open here in the shop to the rain and cold, from getting my newest Hardinge CNC machine in so bare with me.

My whole point of posting here is when I saw comments telling a guy who was trying to build a charger for his system with a 2 hp engine, to look at regulators, etc, is off the mark.  2 or 2.5 hp for an alternator system is indeed a trickle charger.

How in the world is "95 amps off the alternator in 4 hrs that means the alt is only producing 23 amps".   Only producing 23 amps measured by an amp meter on a 24v system? How do you determine that? (I have 95 amps continuous... CONTINUOUS.)

Won't even boil? I've got the little 6.5 running with the bank over 29v gassing and boiling as we speak.

That 95 amps on my system is the equivalent of roughly 3.8kw of the Semiens PV panels I currently own. I wish I had 3.8kw of panels.

Now I don't mean to be disrespectful, or flame anyone. I know my system is limited for certain, but not even close to what you guys say it's doing.

My goal ultimate here is to produce the best fuel efficient DC charging system.

Hi Pat,

No flames here, at least I don't see any, hell I don't even smell smoke.

We need to start by getting on the same page.

watts=volts X amps

95 amps X 24v = 2280 watts

amps = watts / volts

3800 watts /  24 volts = 158 amps


lloyd

Pat,

Here is the math again, you're conversing with three members that know power generation, about five times over your head.

And just for the RECORD, I am a TROJAN bat dealer.

So far to date, I can't understand a single point you are trying to make, bc as soon as someone questions your statement, you go oh I meant this or that.

If you want to have a good discussion you at least need to present the fact, based on the math, and proper understanding of how and where the power is coming from and going too.

Lloyd

[Lloyd]

Something I should have mentioned yesterday- L16 batteries are NOT like your car or deep cycle marine batteries. They like to be boiled, and equalized fairly often. That's the key to their longevity. They are not prone to "plate corrosion" like what you may be used to.

This is a completely wrong statement....period!!!!!

Go to the Trojan website and read their battery charge regime. Their battery fac, and their trouble shooting. They specifically state that constant overcharging will shorten the life of the bat, due to grid plate corrosion.

Remember I am a TROJAN DEALER, and I have had numerous conversations with their engineers.

If your going to blow smoke blow it some other direction.

And just for the record, the Idaho backwoods solar site sells a dc gen kit exactly as you describe yours, are you their manufacturer??

They also have a fac on their website about battery care and charge regime.. and state also that constant overcharging will cause grid plate corrosion.

Lloyd

[OFFGriddnPat]

Well I have not changed one point I've made incase you care to read. Right from the start Lloyd.

So you and I can just disagree.

5 times over my head?  I think your head is five times to big to accept the fact someone may have something to show you that differs from your "Vast Knowledge".

Perfect example- you stated my 31volts equalizing for one hour causes plate corrosion on L16's.  If you're a dealer I suggest you go read.

I could prove anything I write and show my results, but I see it's pointless here. I've got a shop to run and a living to make.

[OFFGriddnPat]

My last comment Lloydd...

If you think the L16 data I've written is damaging, I suggest you call the guys at Backwoods and question there instructions, which is what I've followed and has served me well for years, and them as well with their own systems. I imagine or they would not suggest it if it caused the damage you claim!

I do not manufacture their charger, and mine is modified to what they sell.

I'm done here so you can rest.

[LowGear]

"Math is Hard."

Barbie Doll

[Lloyd]

http://www.trojanbattery.com/Tech-Support/BatteryMaintenance.aspx

3.4. Charging and Equalizing

3.4.1. Charging
Proper charging is imperative to maximize battery performance. Both under- or overcharging
batteries can significantly reduce the life of the battery. For proper charging, refer
to the instructions that came with your equipment. Most chargers are automatic and preprogrammed.
Some chargers allow the user to set the voltage and current values. Refer
to Table 4 for charging guide lines. Refer to Diagram 4 for Trojan's recommended flooded/
wet charging guidelines, Diagram 5 for Trojan's recommended gel charging guidelines and
Diagram 6 for Trojan's recommended AGM charging guidelines.
• Make sure the charger is set to the appropriate program for flooded/wet, gel or
AGM, depending on the type of battery you are charging
• Batteries should be fully charged after each use
• Lead-acid batteries (flooded/wet, gel and AGM) do not have a memory effect
and therefore do not need to be fully discharged before recharging
• Charge only in well-ventilated areas
• Check electrolyte level to make sure plates are covered with water before
charging (flooded/wet batteries only)
• Check that all vent caps are secured properly on the battery before charging
• Flooded/wet batteries will gas (bubble) towards the end of charge to ensure the
electrolyte is properly mixed
• Never charge a frozen battery
• Avoid charging at temperatures above 120°F (49°C


Equalizing (Flooded batteries only)       
   
   


Equalizing is an overcharge performed on flooded lead acid batteries after they have been fully charged. It reverses the buildup of negative chemical effects like stratification, a condition where acid concentration is greater at the bottom of the battery than at the top. Equalizing also helps to remove sulfate crystals that might have built up on the plates. If left unchecked, this condition, called sulfation, will reduce the overall capacity of the battery.

Many experts recommend that batteries be equalized periodically, ranging anywhere from once a month to once or twice per year. However, Trojan only recommends equalizing when low or wide ranging specific gravity (+/- .015) are detected after fully charging a battery.

Step by Step Equalizing:

1. Verify the battery(s) are flooded type.

2. Remove all loads from the batteries.

3. Connect battery charger.

4. Set charger for the equalizing voltage (See Table 2 in the Charging section).

5. Start charging batteries.

6. Batteries will begin gassing and bubbling vigorously.

7. Take specific gravity readings every hour.

8. Equalization is complete when specific gravity values no longer rise during the gassing stage.

NOTE: Many chargers do not have an equalization setting so this procedure can't be carried out.

3.4.2. Equalizing (flooded/wet batteries ONLY)
Equalizing is an overcharge performed on flooded/wet batteries after they have been fully
charged. Trojan recommends equalizing only when batteries have low specific gravity, below
1.250 or wide ranging specific gravity, 0.030, after fully charging a battery. Gel or AGM
batteries should never be equalized.
• Confirm that the batteries are flooded/wet
• Check electrolyte level to make sure plates are covered with water before charging
• Check that all vent caps are secured properly on the battery before charging
• Set charger to equalizing mode
• The batteries will gas (bubble) during the equalization process
• Measure the specific gravity every hour. Discontinue the equalization charge when the
gravity no longer rises

[Lloyd]

The point of all this madness is.

12 Trojan L16's is quite an investment average retail price of $375.00 X 12 = $4,500. dollars.

This bank's return on investment is wholly dependent on a proper charge regime, which must be temp. compensated, as well as voltage and current controlled, and sized to charge effeciently.

It's been proven by thousands of installations off-grid that the most efficient way  is to use a charge cycle regime. 1. The bats receive better care, from the controlled charge. and 2. The engine/generator run at peek performance, charging at the least fuel to charge amps produced. 3. less run-time, wear and tear and maintenance cost for the engine/generator.

The industry standard in off-grid Telco sites, have all changed to this regime...why bc of the return on investment.

Final point an under sized, uncontrolled system will never be able to make the same return on investment, as a matter of fact the cheap under performing setup, will in the end, be a loss instead of return.

lloyd

[Henry W]

OFFGriddnPat,
mobile_bob and Lloyd have been working with DC charging for years and they know what they are talking about. They are very respected here and on other forums. I understand you are new here but I find it very offensive for you to step in and argue with them on this topic. Why don't you work the info they presented to you. Take six months or a year to work it if you have to. You can learn lots by having humility.

Henry

[Carlb]

Really not a good way to join a forum.

[Shipo]

I really don't get it .... these two gentlemen are hard core in DC..."Been there don't that"...and he keep  pushing...just started with a wrong foot...

[OFFGriddnPat]

No problems guys. I understand loyalty amongst friends.

I'm going to move on from your forum here, but I wish leave you with a few thoughts.

I tried to explain from the beginning of this thread what I do with these DC auto alts, for a different perspective to consider.  I mentioned the size of my systems and the limitations of my DC chargers, and that my Trace Inverter handles float charges -with my PV Panels.  And that Backwoods Solar recommends 31volts at one hour for equalization for systems such as mine. Which served me well for my first expensive battery bank starting 13 years ago.

The whole reason I posted this thread was because of statements like this:

You could get your entire 95A out of the 6.5 engine by installing both alternators on it, and still have room to spare... . 

I've read that notion few times on the net here and there, and on this forum with not a peep out of the 3 experts that I've been told are 5 times over my head.

You may think I'm ignorant, have no math skills, and I'm here to cause trouble, but that statement above speaks volumes of actual experience building generators. It ain't gonna work worth squat in the real world, and yes IMO.

So I've read some very reasonable responses- Thank you Bob, But I've been jumped on with some very unreasonable statements, so I tried to further clarify my position respectfully, and then I'm told "my charger can't possibly put out that kind of power", moving on to "that kind of power is damaging my battery bank etc." Moving on to "I change my story."

There it is. I came here to share my experiences, and see if I could perfect my DC Systems, with something better.

Instead of saying, "you can't possibly be doing that", why not say, "If he is, how is he doing it?  How is that possible?"

Instead of saying, "What you're doing is wrong! Based on all of my knowledge", why not say, "well if he did that- how is it that his results turned out differently?"

Keep an open mind guys, and learn.  That's what I do and it's served me well all of my life.

Pat

[mobile_bob]

Pat

you have to understand that for me at least, as i suspect the same with others, we have seen bold claims made by newbies before

bold assertions require bold proof!

also please understand that i for one simply go up in flames when i see yet another guy going on about a little delco running the world.
(i am not saying you have done this, else i would have dumped a ton of rock on your head straight up)

over here we have countless jokers selling delco's modified with neo mags, claiming everything from running your house to a village
for 300 bucks and often less.  we see them advertised for windgen's, gas driven gensets, and all sorts of other crap.

to date there have been very few satisfied customers, and tons of burnt up cheap delco's, dead batteries and folks coming back looking for
the right way to do things.

just like the 200 mpg carb exists (and yes it does, i have seen the book, the tech drawings, and the patent) both it and the delco while technically possible just aren't practical for the vast majority of folks.

just because something can be done is no measure for it should be done.

sometimes taking the cheap way out turns out to be the most expensive route possible, at least that has been my experience in life.

when someone comes forward claiming he can run his whole house, his complete three phase machine shop, all on a chinese clone engine
driving a chinese clone delco 10dn,  and does so for years without problems, well i am left to think a couple of things

1. the guy lives in a one room cabin, and
2. he runs his machines a few minutes per day, or
3. he is full of crap?

there are three rules of sales and i think it applies here as well

you can have what you want
you can have it when you want it
you can get it for cheap

you can have any two but not all three?

bob g

[Ronmar]

We must be measuring amps differently. You guys must be talking about taking an amp reading off the alt, which would be 95 amps in 12 volts, which would read from my 24 volt wired system 190 amps. 95 amps here would put that little 6.5 in the dirt.

There's no way a 6.5hp engine will handle 2 alternators, unless the load was extremely light on both alts- some where around 15-20 amps for a 24v system. The 16hp yes, and you would be puttin' a good grunt load on it.

Really?  There is NO way a 6.5HP will handle 95A@24V?  Have you ever tried it?

I guess I am a glutton for punishment so I will go around once more.
Pat, here are the facts, and just because you do not believe them dosn't make them any less so.
1. Watts are Watts regardless of the source.
2. Sustainable power generation requires 2HP per KW of electrical load.  Look at any generator set, a 5KW set has a 10HP engine, and that is the way it has been since prettymuch humans started turning torque into electrons...
3. I thought we were talking about 24V here, 12V never came into the picture till YOU brought it here.  But since you did, lets go there... Your statement IRT 12V shows that you obviously do not understand this concept. 24V@95amps is 2280 WATTS!.  Now here is one for you to get your brain around if you can. 12V@190A is the exact same ammount of energy, 2280WATTS!.   It would be nearly the same load on your engine to generate it. 12V being less efficient than 24 in the same alternator, would require a little more torque, but within your engines capability.  Even following the old 30A per HP for 12V alternators(I think that is a little conservative), your 6.5 should still be good for 195A out of a 12V alternator.
4.  If your 6.5HP engine is turning at an RPM where it can make it's rated 6.5HP, it should be capable of sustaining either 24V@95A or 12V@190A...

Best of luck to you, save your pennies for fuel and that new battery bank...

I am most definitely dun!