Battery charging question

[Bala]

Those 4RP1800 4volt 1200AH batteries you have are pretty serious.

Looks like they should last those 9 years you have had them but may now be close to dropping off the table. Hope you get another year out of them.

They are on track per DOD V cycles,

They are still holding well, but yes every day/month/year now is a bonus really.

Time will tell.