Community Forums

grammymidge · 06-30-2022, 04:01 PM

Our 2005 Bounder Diesel has been in storage since the 1st of the year. In storage the coach is plugged into 20 amp service to help to keep the batteries charged. Well the other day hubby went to get the RV prepped for summer travel. What he found was the panel showing the status of the batteries (chassis and house) would not display anything. In troubleshooting he discovered that both main batteries were dead, had swelled up, and would not take a charge. The mains are the AGM type and less than a year old. So, therefore, they should not have gone bad so soon. Can anyone tell me the best way to troubleshoot this issue? Also if you have experienced this, what did you find out was the problem and what was the best way fix to it?

Soppy · 06-30-2022, 04:24 PM

It sounds like the batteries may have overcharged while in storage. To further prevent this from happening , install battery disconnects on the house and chassis batteries. When you are storing the coach , make sure the batteries are fully charged , the disconnect them . AGM batteries will be good for over 6 months without needing to be charge. My 14 yr old AGM batteries sit for 8 months without being charged and measure 12.7 v when I connect them.

grammymidge · 06-30-2022, 04:39 PM

Soppy thanks for the response. In fact our thoughts did center on the batteries being overcharged, but then I have to think this is the first time in over 16 years that this has happened and also why did this happen to the mains and not to the house batteries which are also of the AGM type and are fine. Just some thoughts that have me wondering.

wolfe10 · 06-30-2022, 04:56 PM

What were you using to charge/maintain the chassis and also the house battery banks? And, if a smart charger or smart inverter/charger, was it properly programmed?

grammymidge · 06-30-2022, 11:56 PM

Brett in answer to your question, each winter we store the coach in a large garage on the property and is plugged into shore power at 20 amp service the plug of which is connected to a circuit breaker box not a charger. We have set the power panel for 20 amps. All electronics, appliances, and lights in the coach are shut down. This has been the case each winter for the last 5 years with never a problem of any of the batteries over charging until this year.

Soppy · 07-01-2022, 05:47 AM

Your batteries may have suffered "thermal runaway" and slowly destroyed themselves. This will happen if your charger is not temperature compensated and the batteries start getting warm while being charged. As the temperature of a battery increases the fully charged voltage drops. If your charger keeps a constant charge voltage on the batteries they will produce heat while being charged and will draw more current causing the battery to get hotter. This will continue till the battery boils dry or melts.

grammymidge · 07-01-2022, 02:24 PM

Soppy from the appearance of the batteries your description sounds like this is what happened to them. This is where my and my hubby's inexperience with the way the batteries on the coach charge while on shore power is causing me to ask further questions. Since the only batteries affected by this were the mains and the house batteries were not affected, does this mean the way they are charged while plugged into shore power is different from the way the house batteries are charged? The house batteries have a temperature gauge connected going to the inverter but the mains do not. Is there anywhere I can obtain documentation that explains the process for charging when the coach is hooked up to shore power?

wolfe10 · 07-01-2022, 02:36 PM

Quote:

Originally Posted by grammymidge

Brett in answer to your question, each winter we store the coach in a large garage on the property and is plugged into shore power at 20 amp service the plug of which is connected to a circuit breaker box not a charger. We have set the power panel for 20 amps. All electronics, appliances, and lights in the coach are shut down. This has been the case each winter for the last 5 years with never a problem of any of the batteries over charging until this year.

Sorry, not sure I understand. Exactly what "device" uses the 120 VAC and converts it to 12 VDC.

And, does it charge both HOUSE and CHASSIS batteries? Only your voltmeter knows for sure.

Kid Gloves · 07-01-2022, 03:04 PM

When you installed AGM’s less than a year ago, did they replace FLA’s?

For what length of time have you owned this coach? Previous posts suggest somewhere between 5-16 years and that you are unfamiliar with the battery charging system.

twinboat · 07-01-2022, 03:13 PM

It may be that the chassis batteries are no longer being charged while on shore power.

Replace of charge them and then plug it in to shore power.

If the bi-directional charging is working, the chassis batteries volts should move up to 13 volts or more.

The failure of the solenoid that handles isolating and combining the batteries is much more common then thermal runaways.

grammymidge · 07-01-2022, 04:25 PM

Quote:

Originally Posted by Kid Gloves

When you installed AGM’s less than a year ago, did they replace FLA’s?

For what length of time have you owned this coach? Previous posts suggest somewhere between 5-16 years and that you are unfamiliar with the battery charging system.

Kid Gloves in answer to your questions
- last year the batteries replaced other AGMs
- we purchased the coach new in Feb 2005; therefore we have had it 17 years.
- and no I am not familiar with the charging system. Hubby has been the one to maintain the coach since we purchased it. He seems to think the inverter over charged the batteries yet from what I see from other posts here the inverter does not charge the mains but then again my understanding is the inverter/charger is the only charging device on the coach so what would be charging the mains while on shore power if it isn't the inverter?

I'm at a loss here and to deal with the battery manufacturer I am hoping to gain as much knowledge as I can to obtain warranty replacement if possible.

BC Buck · 07-01-2022, 04:29 PM

Your giving good input and these guys should be able to help.

twinboat · 07-01-2022, 05:10 PM

Your inverter/charger handles charging of all of batteries, the house batteries directly and the chassis batteries thru the bridge or isolation solenoid. Same thing different name.

For the chassis battery to overcharge, the house batteries would have also overcharged, actually they should have overcharged first.

Your chassis batteries probably died a slow death due to not being charged and parasitic loads using it up.