[john61ct]

Seems normal.

Depending on charger amps output it could easily take over ten hours to fully charge from 50% depleted.

Aged lowered capacity batts can take much longer.

Even a small healthy bat is 5-7 hours.

100% Full would mean tail amps dropping to say under 5A.

Are those supposed to be quality true deep cycling? Not according to vendors, but trusted objective sources.

 

[john61ct]

Depends on the charger, if it transitions to Float after Full NP.

They say those batts are only rated for maximum 500 cycles at 50% DoD, way less if you've been going deeper.

Not what I would call true deep cycling.

IOW they're shot, replace with better.

IMO the best lead battery value by far is Duracell (actually Deka/East Penn) FLA deep cycle golf cart batteries, 6V, around $90 per @200+AH from BatteriesPlus or Sam's Club

But keep DoD below 50% if you want longevity.