Solar while the RV is in Storage

[dufferdj]

Need some guidance for how to use solar while in storage. My solar panels are suppling a daily charge, topping off both my house and chassis batteries. Each night my class A has the charge drawn down due to minor drains . That means that my battery charge will rise and fall daily, if only a small amount. If I shut off the battery disconnects that would prevent this fluctuation. Should I leave my batteries "live" so that they will charge during the day and slightly discharge each night or do I flip the disconnect switches to keep the batteries from either increasing or decreasing their charge. Which method should extend the life span of new batteries, or does it really matter? Thanks for sharing your knowledge and opinions.

[CA_Traveler]

For example you have a 1A drain or 24Ah in a day. Even 0.1A is 2.4Ah for a day. Plus battery self discharge. And 0.1A is 72Ah a month.

Maybe your best option is switches off and solar on. Good for a few AZ overcast days and CO winter not so much unless of course you are a snowbird.

[CA_Traveler]

There is NO pat answer to your question. Likely your disconnect switches don't remove all drains. One approach is to completely disconnect the batteries (remove cables, full disconnect switch, etc), rewire the solar to the house bank and add a jumper to the chassis bank.

Because my AGMs have a low self discharge rate I choose for a variety of reasons to install FULL disconnect switches on the batteries and fully charge them once a month. Strange since I have solar??? - stored semi inside with minimum daily solar and other factors involving Monaco's marginal wiring setup - a long story...

[Ed_Gee]

I believe most RV solar charging systems are wired directly to the battery bank, by-passing the disconnect switch.

[Lwiddis]

I cover my TT when out of use and use a 30 watt solar panel mounted on the roof cover and $22 controller from WindyNation to keep the batteries charged. Works great.

[DrewE]

Lead acid batteries self-discharge even if completely unconnected; the rate of this self discharge is dependent on many factors, including the battery construction, its age, and (notably) the ambient temperature.

If you were storing outdoors in subfreezing temperatures, fully charging then disconnecting the batteries is fine. In a warm climate, that's not so good a plan. I'd leave them hooked up to the solar and the rest of the RV in your shoes, assuming that the storage location generally gets enough light to keep them up to snuff. It might also be possible to connect the solar charge connection on the other side of the disconnect switch without much effort so as to have them kept nicely charged without the parasitic loads in the RV discharging them.