Showed up with 100w hinged solar panel for brother that abuses batteries.
He had recently added an AGM/parallel to his flooded. He got the AGM due to low self discharge. 11.4v. Would not hook up extension cord for WFCO or smart charger.
"something must be discharging", not kidding, CO/propane + flooded, use a disconnect "no, maybe later".
Painful.
I'd save my money for 100% recharge method.