HELP!!! Coach batteries not recognized by inverter

I agree with Fred- quite often these coaches use 24 volt inverters. I disagree with Fred about the alternators costing $450 though- I believe 270 amp oil cooled alternators are the smallest Prevost used, with builders either adding a second, or installing larger.

They make 24 and 12 volt Inverter/chargers. WHICH do you have??? I will bet a 24 volt Inverter/charger. Your problem and solution depends on which you have. Doug

My guess is the starter and inverter are on the 24 volt system.

My next guess is the inverter is only connected to 12 volts at the coach batteries. Also lets hope there is a 100 amp fuse (give or take) for the merge switch, so that if I am right, and the coach battery for the inverter where wired wrong, then it will trip the fuse, not put 24 volts to a battery bank incorrectly wired for 12 volts.

My guess is the inverter and it's 4 batteries are in one bank, and anoter bank is for the 12 volt system that only runs the house lights, pump, aqua hot and inside fans.

I am also guessing that the engine has two alternators, one for the 24 volt starter batteries, and now it also runs the inverter battery bank, and also a 12 volt system for the headlights, some controls, running lights, and small loads. IT should also be charging the 12 volt battery bank.

There might be a 24 volt to 12 volt converter, but it would have been easier to install a second alternator back in 85, so they did it that way back then.

If your inverter has a remote control system, check the input voltage in the system. If it reads low voltage when not merged, see if it says 12.8 input. Then switch it on with the merge switch, if it reads 24 volts input, then you are applying 24 volts to a 12 volt battery bank, don't do it for very long, the battery will overheat and might explode. (30 seconds should be OK).

If this is what you found (inverter needs 24 volts input, but only has 12 volts input) you can change the inverter battery from 2 or 4 in parrelle to in series so that you get 24 volts output. Not all 4 in series *unless they are 6 volt with only 3 cell caps on each battery) if you have 12 volt battery, then two in series makes 24 volts. If 6 volt for each battery, then 4 in series makes 24 volts.

Sounds like you need to have the guy who installed the batteries look at it again. Probably just need to change around a couple of wires to get it back to normal. He might not have guessed the inverter has a 24 volt input to it, and wired all the batteries to 12 volts instead of some to 12 and some to 24 volts.

But I might have all this wrong, so it will take a mechanic putting hands on it, looking at the inverter input volt rating, and everything else to make sure it is right. It really sounds like you will need a electrician on the site.

I would also causion you about driving it or running the engine to much. IF the 24 volt alternator is connected to a battery wired for 12 volts, those batteries can overheat, and possibly explode. Or you might melt down a $450 130 amp 24 volt alternator. And it is possible that Leese Nivell is no longer in business, so getting a new alternator might be difficult, rebuilding is possible though.

Fred.

moved from technology corner

MtLaw wrote:


The house batteries were replaced this year. The guy who did it for me is very bright and handy and believes the coach worked properly after he was done w/ the new coach battery installation.

I know nothing whatsoever about batteries, but EVERYTHING about tracking down the source of a problem that arises immediately after a self-described "expert" works on something. (This from almost thirty years of marriage to such an expert ;) )

Regardless of what your helper "believes", the coach doesn't now do what it did before he got his hands on it. He's the only person that knows what he did to cause the change- he should track back through every step and find out where the mistake came in.

With you watching, I might add...