Factory solar panel queston

[Diesel-Gypsy]

The 2004 TK3 I recently purchased came equipped with the little solar panel mounted on the AC unit.
I traced the wires directly to the batterys.
The panel was wired directly to the dual 6 volt batteries.
There doesn't seem to be any type of controller in that simple system.
Does anyone familiar with that factory option have any input on this set-up?

I am curious because this constant charge situation was what I beleive to be the root cause of serious battery boil-over in the coach I purchased.

Any thoughts, resolutions?

Thanks,
Rick

[Motor31]

Chances are that it's a small solar trickle charger. It won't likely be able to boil over the battery bank.