Solar while the RV is in Storage

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.

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.

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

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...

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.

Sounds fine to me unless the voltage on the battery is dropping significantly. Depending on conditions you could be a week+ with minimal to no solar.... will that be a concern?

My PV system is direct connected to the batteries and has its own shutoff. Of course, I designed and installed the system myself so YMMV.

time2roll wrote:
Sounds fine to me unless the voltage on the battery is dropping significantly. Depending on conditions you could be a week+ with minimal to no solar.... will that be a concern?

Good suggestion, get a digital voltmeter that will read 2 digits and see what is going on. Like 12.68V.

Better get a AC/DC clamp on meter and check the battery drain. So much better than "minor" drain. Reasonable ones are about $80.

Yup, for a more considered answer, you will need to tell us how low the voltage goes.

So, what is float voltage at the end of a sunny day? How low in the morning after a couple of cloudy days?

Also, what controller do you have? Quite a range of quality/capabilities.

Thanks to all for your replies thus far. I know that I need new batteries so I'm trying to figure out what to do so that the new ones will last as long as possible.
At the end of a sunny day after the sun is low in the sky, so that I'm not really getting any more solar gain, my Blue Sky 3000i Solar Boost controller shows 13.0 with the Float and Absorption lights lit up. The next morning before sunrise it was reading 12.1. Nothing was being used in the RV as it was in the storage lot --- no TV. no lights, no heat --- no nothing other than the random draws from the house electronics.
Last night, after a sunny day the controller showed a reading of 13.0 F/Ab. I turned the disconnect switches off on both the house and chassis battery banks. Checked them again this morning prior to sunrise and got a reading on the controller of 12.7/6.
This info seems to tell me that by disconnecting the battery banks, the voltage drops significantly less than when leaving them connected.
Once I install new batteries I'm sure these stats will change. But from what you can see, would I be better off just leaving the batteries connected to the solar panels 24/7, or disconnect the battery bank and just reconnect it one sunny day a week? Which way will extend the life of the new batteries or does it really make a difference ?