Isolator that can support 5 batteries?

[bobburns]

Do not mean to hi-jack - but I am asking if anyone knows of an isolator that can support 5 batteries

I have a 97 turbo diesel Gm Savanna custom Braun Mobility hi-top (10 foot tall with standing room all the way and rear A/C and heat with side condenser mount) with 5 AGM Super Start AGM 31 deep cycle batteries and the isolator I had could not handle the amperage my alternator can put out

It is 250 amp stator with 70 amp non-avalanche diodes used with a Penntex PX-1000 smart charger external regulator.

In other words the internal GM unit is not used and the field is drawn directly from the stator and brushes

It is what is known as a welding setup with a 1.8 inch pulley for full output at idle

With non-avalanche diodes the unit can put out it appears up to 1000 amps - at least that is what my amp meter reads - it pegs at 999 amps

I use a 30 amp pure sine inverter to power microwave, refrigerator and power tools etc and the engine has an automatic PTO circuit that ramps up the engine RPM to 1360 (GM's ECM feature) if the battery draw gets below 12.6 volts

If I run the batteries low - the unit will put out 999 amps and then slowly drop as they charge all the way to cut-off and 80 amps "float" - and the batteries will be fully charged at 13.1 volts. (that is their float for these AGM's) charge rate is 14.4 volts.

It takes about an hour idling the engine to push down to 300 amps from a 12.3 or 12.4 volt level to a charge rate which is 12.9 volts float - about 50 percent full charge and maybe 30 minutes more to finish

The batteries are wired in series and each one allegedly has a smart circuit to stop charging the battery when full

I have never run these so low as to not be able to start the engine - and the previous isolater with wet cell batteries did not work well - it over-charged (boiled) the isolated one - while trying to charge the interior ones. Plus - who like wet cell batteries they stink - and these AGM's are sealed.

In series all hooked together I have had no problems - but I cannot find a multi battery isolator - so does anyone know of one ?/

[markopolo]

How about adding an option to bypass the isolator temporarily using a make-before-break type multi battery switch. You could keep an eye on the amp flow and switch back when it drops below 100.

One problem would be if you forgot and left them joined you could drain the starting batteries. I have this setup in my van and haven't forgotten yet.

The battery switch I use is only rated 300 amps (I think).

[bobburns]

Yes I have that already - I leave it on - because it is in the drivers step well and a pain to cut on and off without opening the door and getting out

With the five batteries I have effectively about 4000 cranking amps available and 5000 cold cranking amps - and since they have effective 1000 min reserve (16 hours) - I really can't run them down to where it won't start since I drive it everyday.

These are the size batteries I have => http://www.oreillyauto.com/site/c/searc ... rd=agm31dt

I can actually run the microwave (a 700 watt version) for about five minutes (like to pop popcorn or warm / cook anything as a personal meal that is frozen) without running the engine but I do not do so usually - so I wanted the isolater for "insurance".

When I run it with the engine idling - about 3 minutes into full power on the microwave the fast idle will kick on and bring the engine up to 1360 RPM and reads 800 amps charging at 14.2 volts

I have 135 watt worth of solar panels and controllers I think I will move from my retired Class C (20 foot Chevy G-30 style) now to this one and forget the isolater idea - because it appears there is no such isolater creature that can do what I need - at a price that would not be as costly as adding another 45 watts worth of solar panel array. Parked in the sun they have held their own pushing about 10 to 12 amps (DC) charging current to keep them charged for what I use on them daily. I have room for one more array.

Instead I think I will mount a second high amp alternator in case something fails - that I can switch over to it - automatically while I repair the first one.

GM already has the dual alternator mount setup built into the AC - PS drivers side cast mounting bracket. You just add a idler pulley and holding plate to mount the second alternator - at least on my engine. When the voltage is high enough the second GM internal regulator will keep the second unit automatically off - or run it at float voltage

[booster]

I must be missing something here. 5 group 31 AGM batteries that are CCA rated not AH, would indicate starting or combo batteries, not deep cycle. probably in the range of 550AH, so if you have 1000+ amps of alternator hitting them you are at C2, which is a very high charge rate. Lifeline says inrush can be C5 without damage, but at high rates you need to very carefully be temp controlled on all batteries, and they will heat very quickly. That brings up the 5 twelve volt batteries in series would be 60 volts, but you say you charge at 14.4. What voltage does the inverter run at? Having 5000CCA is probably a moot point. Do you have wiring big enough to carry it, or a starter that could pull even 1/4 of it? If the batteries are in series, how do you switch them to parallel to get 5000CCA at 12v?

The "welding" alternators I have seen are usually very dirty power, so they would need a very good DC to DC multistep charger. Do you have a 1000 amp DC to DC charger, or just the external regulator? 80 amps is very high to be going to float on 550AH of batteries at nearly 15% (ending amps to capacity ratio). More typically, the manufacturers recommend 1-3% with new batteries being on the lower end. My guess is that the regulator may be switching based on voltage, not current, so it goes to float as soon as it hits absorption voltage, or very soon after. Stopping that early will almost certainly leave your batteries less than full, probably in the 80-85% range.

For 1000 amps of charging, you would need a 600MCM cable off the alternator to the batteries. If you are using a clamp on ammeter, it may be giving a false reading due to noisy power. A 250 amp alternator will overheat extremely quickly at 1000 amps.

This whole thing just makes no sense to me, as to what it is, or what you are trying to achieve. I think some more information could do some good so we can better understand the system and what it is intended to do.

[markopolo]

I'm curious to learn more about the system also.

And, have you sourced the aux alternator bracket (GM part 10244209) http://www.classbforum.com/phpBB2/vi...p=18312#p18312 or will you make it? Your van and my van have the same model engine so I hope you stick around. Not many camper van have that motor it seems.

You might be interested in this fast idle mod: http://www.classbforum.com/phpBB2/vi...hp?f=12&t=2295 . It can give you up to 4 manually controlled idle speeds: 624 RPM (approx), 1070 RPM, 1360 RPM, 1600 RPM. 1070 would be quieter than the 1360 you mentioned and might be adequate for camping needs. I don't know how it would interact with your automated system.

[bobburns]

Originally Posted by booster

If the batteries are in series, how do you switch them to parallel . . . A 250 amp alternator will overheat extremely quickly at 1000 amps.

This whole thing just makes no sense to me, as to what it is, or what you are trying to achieve. I think some more information could do some good so we can better understand the system and what it is intended to do.

My mistake I meant to say wires in parallel

An alternator heats up from either switching the internal regulator or not having enough capacity to charge the battery bank. for more info generally here is link => https://sites.google.com/site/wirewiz/Home/Alternators

My post describes the alternator and smart charging regulator - which is external and large enough in an aluminum finned case of its own to dissipate heat. What you call dirty power is cleaned up by the regulator. In short it allows full output if the battery bank needs it and shuts down lower or off the alternator to mostly no output if the batteries are fully charged. So yes smart regulators do vary amperage output depending the system draw. The GM internal regulator would just overheat - run hot - and fail quickly in a few months. The full system is #2 cable. See http://www.penntexusa.com/Regulators.htm The batteries are smart also - but you will not find that info on the manufacturers site => http://www.eastpennmanufacturing.com/wp ... r-1741.pdf (they make the super start)

It works fine. Wet cell batteries, yes, however would heat up and boil

I am not here to explain the system - I was asking it anyone know of an isolater that could handle five or six batteries

[bobburns]

Originally Posted by markopolo

I'm curious to learn more about the system also.

And, have you sourced the aux alternator bracket (GM part 10244209) http://www.classbforum.com/phpBB2/vi...p=18312#p18312 or will you make it? Your van and my van have the same model engine so I hope you stick around. Not many camper van have that motor it seems.

You might be interested in this fast idle mod: http://www.classbforum.com/phpBB2/vi...hp?f=12&t=2295 . It can give you up to 4 manually controlled idle speeds: 624 RPM (approx), 1070 RPM, 1360 RPM, 1600 RPM. 1070 would be quieter than the 1360 you mentioned and might be adequate for camping needs. I don't know how it would interact with your automated system.

I just made my own bracket - it is just flat steel and some sawing with a jig saw and drilling holes - and one I tapped. Thanks for the link but - the fast idle is controlled by a Penntex fast idle system which triggers the ECM and shuts off with the brake like cruise control => http://www.penntexusa.com/High-Idlers.htm I could change RPM by chaning the pinout - trigger in - of the ECM also.

I have a second External Regulator (Penntex PX-2000 style) I may use for the second alternator, and mechanically shut it off by a switch (no excitation to the rotor) until needed if the main system fails

[booster]

Originally Posted by bobburns

My mistake I meant to say wires in parallel

An alternator heats up from either switching the internal regulator or not having enough capacity to charge the battery bank. for more info generally here is link => https://sites.google.com/site/wirewiz/Home/Alternators

My post describes the alternator and smart charging regulator - which is external and large enough in an aluminum finned case of its own to dissipate heat. What you call dirty power is cleaned up by the regulator. In short it allows full output if the battery bank needs it and shuts down lower or off the alternator to mostly no output if the batteries are fully charged. So yes smart regulators do vary amperage output depending the system draw. The GM internal regulator would just overheat - run hot - and fail quickly in a few months. The full system is #2 cable. See http://www.penntexusa.com/Regulators.htm The batteries are smart also - but you will not find that info on the manufacturers site => http://www.eastpennmanufacturing.com/wp ... r-1741.pdf (they make the super start)

It works fine. Wet cell batteries, yes, however would heat up and boil

I am not here to explain the system - I was asking it anyone know of an isolater that could handle five or six batteries

Not going to get into a mess here, so no, I don't know of an isolator big enough, but then again we don't know how big. If you can't/won't explain the system, that's fine.

But #2 wire is good for 200 amps, not 1000.

The link you show for the regulator shows no hi current wiring, and no shunt, so it can't be measuring amperage, and it can't be cleaning up the power. It controls voltage, not current.

Alternators overheat from undercapacity, as you say, but you are also saying you are pulling 1000 amps from a 250 amp unit, and do it through #2 wire.

Those batteries are no smarter than any other AGM, it appears, nothing in the link to say otherwise. What makes the battery smart?

No more questions here

[markopolo]

I couldn't find any info re: 12v 1000 amp isolators online either. My guess is that typically the voltage is upped to 24v, 36v or 48v etc. as power needs increase. That keeps the wire size manageable.

With the two alternators you could skip the isolator altogether using one alternator for the chassis needs and one for the house needs. One less part to fail.

[bobburns]

Originally Posted by booster

Not going to get into a mess here, so no, I don't know of an isolator big enough, but then again we don't know how big. If you can't/won't explain the system, that's fine.

But #2 wire is good for 200 amps, not 1000.

The link you show for the regulator shows no hi current wiring, and no shunt, so it can't be measuring amperage, and it can't be cleaning up the power. It controls voltage, not current.

Alternators overheat from undercapacity, as you say, but you are also saying you are pulling 1000 amps from a 250 amp unit, and do it through #2 wire.

Those batteries are no smarter than any other AGM, it appears, nothing in the link to say otherwise. What makes the battery smart?

No more questions here

It is quad wound stator, and puts out 190 amps at idle - can spike to 550 amps when driving if needed. It is a special built alternator. I do not know the full curve of the alternator. The shunt for the amp meter is at the ground side of the battery bank, the voltage regulator, is set to float 13.1 and charge 14.2 - it tapers off voltage and amperage as the charge saturation increases. The rating on #2/0 welding cable (which is what I am using off the alternator(s) is 450 amps. It pegs at 999 amps for a short time - maybe two to three minutes. There are over charge protection circuits on the batteries.

[bobburns]

Originally Posted by markopolo

I couldn't find any info re: 12v 1000 amp isolators online either. My guess is that typically the voltage is upped to 24v, 36v or 48v etc. as power needs increase. That keeps the wire size manageable.

With the two alternators you could skip the isolator altogether using one alternator for the chassis needs and one for the house needs. One less part to fail.

I am using the second one as an automatic backup. It has an external regulator I set a few tenths above the primary so it won't cut in unless the first is really under load (edit - actually UNDER I mean

Does your 6.5 Turbo Diesel have an Intercooler ? Did you install one ??

[markopolo]

No intercooler on mine as far as I know. (not a mechanic) I identified all the coolers I could see, radiator, engine oil, transmission fluid, power steering - that's all it has (I think).