[sailingdog]

They're likely dead. If you ran them flat and didn't recharge them for several months...with a load on them, it is likely that you killed them.

I'm stupid an lazy, please don't rub it in.

I let my 3 2-year-old Optima batteries run flat in a frozen boat all winter.

Now it seems like they're not holding a charge...can't tell for sure because the boatyard keeps unplugging my extension cord after I leave. But they're dead upon return, even though the do hold a charge for a while as evidenced by cabin lighting after I've been hanging out while the charger has been on for a few hours.

The charger is a good one, a Heart Interface inverter/charger combo, set to AGM appropriately.

Is there anything I can do to resussitate these batteries?

Is it likely that my mistreatment would kill 'em?

3 x $200 , yuck.

 

[sailingdog]

The desulfators and the Algae-X devices all belong to the category of "IF THEY REALLY WORKED EVERYONE WOULD BE USING THEM"... but they don't.