I leave mine on all the time, several years now, only disconnect if I'm doing some sort of maintenance on the circuit. I find the solar controller does a much better job at charging the batteries than the OEM charge converter but I leave it on for evening charging and in case the day is cloudy. The solar controller I have gives me advanced control of all the voltages for the different phases of charging so I can dial it in for my brand and type of batteries, much better than the charge converter.

I guess you may want to check the solar controller manual but as far as I know, most people leave the solar on as well.

Thanks Ray I’m going to leave it connected than. I have the same controller and monitor you have so all is well.

No reason to disconnect solar. Both the solar charger and the 120v power charger/converter uses voltage to adjust charging. They will both work together charging as well as reducing charging as battery voltage rises.

As Ray mentioned the solar charger is typically more sophisticated than the stock RV charger/converter for battery charging.

My husband installed a solar set-up on our 2000 model Class C motorhome. We found that we need to turn off our solar panels when we are driving. We were driving down the road one day, and our battery light came on. Apparently, solar panels were overcharging the chassis battery. We turned off the solar panels, and the battery light went off immediately. We do not understand the exact issue that would cause this, but if anyone has an idea, we would love to hear your thoughts.

Maybe your solar controller is programmed to output a higher voltage during one of the charging phases that is appropriate for your coach batteries but your vehicle sensors think its too high for the starting battery. Most alternators put out 14.4 volts max but for instance, my solar controller at times will put out as much as 15.2V if its cold out or doing a battery equalization cycle. During absorption I have it set at 14.8V. I believe most lithium types are a 14.6V charging voltage.
If the starter battery circuit sees that voltage maybe it is thinking the alternator is failing and putting out higher than normal voltage.
Just a guess as to what is going on.

I'm curious what the components are for the solar charger. Is the charger programmable and if so what are the values that were set? Most chargers can be set either with custom profiles or generic presets like FLA, AGM, GEL. How many watts of solar do you have? Knowing the model of the charger may help with advice. Perhaps an adjustment in the solar charger could help if it isn't correct.

Does the dash light always come on and right away? If it only came on once Ray has a great theory that the charger had gone into equalization mode which puts a high voltage charge on the battery. That feature can be controlled on some chargers where you do it manually at a time when you are not driving, are in full sun etc. If you shade the solar panels as opposed to turning them off does the dash light go out? Really the solar charger should be optimized for the coaches battery, not the starter battery.

I discontinued the connection between our starter battery and the coach battery. The starter battery and alternator only run the truck. The solar and coach battery only run the coach. There is some loss of charging when we are driving from the alternator but the solar charges the coach battery far better than the alternator and I really didn't want the variable voltages the alternator may provide on my coach battery and our array is large enough to make alternator trickle charging moot.

Is your husband pretty savvy with DC electrical systems? If it doesn't bruise any egos it might be worth having a pro review the system and offer advice. Good luck!

We have gone to solar this last year and have lots to learn. We went to lithium batteries and found that they were changed up to 100% by two or three each day. When we put the batteries were at100% all the time when in storage and after calling the battery manufacturers they said the batteries would last longer stored at 80%. There fore to unplug the charger and let the batteries go down to 50% then charge them back to 100% then unplug them again. The over charging only was a problem when in storage.
Just a thought

Power transfer switch does our work.

Just wondering. If the batteries are charged to 14.4 volts could that much voltage harm any 12v circuits in the rv? Maybe the thermostat or the refrigerator?

Shouldn't be an issue the RV stuff is designed with some overhead voltage room, usually up to at least 16V. An alternator puts out 14.4V, so all the motorhomes are usually charging off that when underway. I've had my system up over 15V routinely when the solar was doing a final equalization mini charge on my lead-acid batteries or when it was cold, and temperature compensation kicked in. Haven't had any problems.

I'm going to start wiring up my first solar system this morning and I had a question about whether people left their solar on even when they're not using the RV and how to wire that up in relation to a disconnect switch. Our trailer will be sitting on a remote property we own most of the time so I'd like to leave it on when we leave one weekend, and hopefully it would be charged up by the time we got back the next weekend.I will be using the Trimetric BMS.

After watching the three videos of Eddie this morning it looks like he wired the solar controller directly to the fuse block before the Blue Sea battery disconnect.so he can shut off the whole trailer and still leave things charging. That's my current plan, just want to make sure it makes sense and is safe to leave the Trimetric hooked up year round even if we're not near the trailer.

Thanks

Travis

As long as the circuits are fused for protection there shouldn't be any harm, people leave trailers plugged on all the time with charge converters running.
I have a separate disconnect for my main RV circuits using a switchable breaker.
Here is how mine is currently setup:

Thanks I appreciate it.