Coach battery problem

[Siebrands]

I'm having a coach battery problem. My two coach batteries failed in my 2007 Winnebago Aspect. When I went to replace them,* I learned they were 2 lawnmower batteries, each 12 volts. They worked fine, so I wasn't too concerned. I bought 2 new lawnmower batteries and installed them in parallel,* just as before. They worked fine for a couple of weeks but now they failed again.* I can recharge them,* but I imagine the same thing will happen. They don't seem to recharge when I'm connected to shore power nor when I'm driving.* I'm at a loss to where to look for the cause of this problem. Any suggestions?

[Persistent]

* I can recharge them,* but I imagine the same thing will happen.

First, do recharge them soon. They need to be stored fully charged. Leaving them discharged will kill them fast.

They don't seem to recharge when I'm connected to shore power nor when I'm driving. I'm at a loss to where to look for the cause of this problem. Any suggestions?

Loose or corroded connection.
Check both positive and ground connections.

Both methods of charging don't usually fail at the same time. Usually a fuse, circuit breaker, or relay fail and one method of charging or the other fails.

I am not sure what "lawn mower batteries" are. If they are lawn mower engine start batteries, they will fail quickly. If they are electric lawn mower batteries they may last longer.

However, either way they would likely be too small to work well for you.

"Cold Cranking Amps"
If they have a cold cranking amps rating, they are likely engine start batteries.

"Amp Hour Capacity"
If they have an amp hour capacity rating, they may be deep draw batteries.

How many amp hours are they rated for?

Motor home coach batteries must be "deep draw" batteries. Most have at least 200 amp hour capacity. Some have 400 or more amp hour capacity.

Motor home engine start batteries (chassis) have a "cold cranking amps" rating. See your chassis owner's manual for required capacity.

[Siebrands]

Re: my failed coach batteries, I noticed/heard a continuous clicking outside near my coaches generator. Trying to track it down, it dawned on me that I had been running the generator a few days prior and had noticed a sticky on/off switch. So checking the switch, indeed it was stuck in the off position! Adjusting it, the clicking stopped, and I’m assuming that’s what was draining my coach batteries. I’ll monitor them to see if my observation is correct...and try and tinker with the sticky switch. Thanks for your reply.