Airstream Forums

Airstream Forums (
-   Electrical - Systems, Generators, Batteries & Solar (
-   -   Curiosity Question: Solar (

Atsushi 09-12-2017 02:08 PM

Curiosity Question: Solar
If solar panels are charging batteries via charge controller, can you or should you plug into shore power? Wouldn't the converter convert AC power into DC and charge the batteries? Wouldn't that be harmful to the batteries to have two sources of charging?

Sorry for my ignorance.

TheGreatleys 09-12-2017 02:17 PM

The solar controller will "see" the voltage that the converter is putting on the system and adjust accordingly. It's designed to moderate the flow of power to the batteries, and it does that by monitoring the voltage of the system. Once the voltage gets high enough, it assumes the batteries are full and shuts off.

The converter has similar logic.

You've got two guys filling the same bucket with separate hoses. Both guys are watching to make sure they don't personally overflow the bucket. No problem.

rmkrum 09-12-2017 02:19 PM

I have solar with an MPPT controller, and currently the old, crappy single-stage convertor. They don't seem to fight each other, but the plan is to swap to a 4-stage converter to get better performance on shore power.

I see from the solar current display that if the converter is running, the MPPT controller basically goes to sleep, and does not push any current into the batteries, based on the voltage it sees. My solar is wired direct to the batteries.


(On Edit: TheGreatleys have the simplest answer for the real situation...)

uncle_bob 09-12-2017 02:34 PM


Simple answer - no it's not a problem.

Of course no thread anywhere would ever be complete without a plug for "Uncle Bob's super battery fixer of all problems" .... very few Bitcoins will get you one delivered real soon now :)

Just as with other chargers, some solar chargers need to be set up to match the type of battery you have. Past that there isn't a lot to hassle with. The size of solar you can fit on an RV will only supply a modest amount of current. Compared to the battery size that gets teamed up with them, that also helps keep you out of trouble. If the two chargers both had similar capacity, then indeed coordination would result in a healthier battery. Regardless of all the hype, there is still a long way to go in the world of RV battery management. That's true no matter which gizmo you buy. There isn't much of a market for $80,000 RV charger / battery combo's.


richw46 09-12-2017 04:19 PM

My solar is factory installed, I have upgraded to a PD-4655 converter. When not on shore power, the solar keeps the batteries charged while in storage. When I am on shore power the solar controller sees this and stops charging unless the switch is in Store, then it switches back to solar. Also, when not on shore and I disconnect the cables, the solar detects this too and stops sending current through the cables. At least, that's what the AS help line told me. I never grounded the cables to see if it shorted out. :)

All times are GMT -6. The time now is 11:00 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.