Recharging depleted AGM battery
Posted: Tue Jun 19, 2018 7:26 pm
Thanks to Jim and this forum I learned a year or so ago that the flooded-cell lead-acid batteries that my Whaler dealer used to replace the batteries on my 2007 235 Conquest with a 250 Verado were incorrect. I was astonished to learn that they didn't use AGM batteries when the Verado owner's manual clearly states that only AGM batteries should be used. I pointed this out to their service manager and his response was along the lines of, "whatever--we wanted to save you money."
So this spring, at great expense, I had the boat serviced at the local Whaler dealer and the batteries replaced with the proper AGM batteries. Since I'd had difficulties with the old flooded-cell lead-acid batteries maintaining a charge, I asked the service manager to check the alternator output on the Verado, and I was assured that it was okay.
I discovered last week that the anchor light had been left on and the starboard (#1) battery was fully depleted. No problem, thought I, I can start the boat off the #2 battery, switch it to the #1 battery, and run it up the ICW for half an hour to recharge #1. No joy.
Then I got my Schumacher battery charger, which has a specific setting for charging large AGM batteries, and, after several days of trying to charge the battery, there's still no joy.
I get a "bad battery" warning on the charger after several hours of attempting to charge, and this after multiple attempts.
So a brief web search informed me that AGM batteries can be difficult to resuscitate if fully depleted. I'm wondering: do I have a bad battery?
It was installed only a month ago. Or am I not recharging the battery properly?
If it's truly a bad battery, I could have the dealer replace it (again), but I'd like to fix this myself if possible since getting to the Whaler dealer service department would involve significant amounts of free time which I do not have.
Any advice would be welcome. It should be fairly obvious to all that I know only enough about electronics to be dangerous.
So this spring, at great expense, I had the boat serviced at the local Whaler dealer and the batteries replaced with the proper AGM batteries. Since I'd had difficulties with the old flooded-cell lead-acid batteries maintaining a charge, I asked the service manager to check the alternator output on the Verado, and I was assured that it was okay.
I discovered last week that the anchor light had been left on and the starboard (#1) battery was fully depleted. No problem, thought I, I can start the boat off the #2 battery, switch it to the #1 battery, and run it up the ICW for half an hour to recharge #1. No joy.
Then I got my Schumacher battery charger, which has a specific setting for charging large AGM batteries, and, after several days of trying to charge the battery, there's still no joy.
I get a "bad battery" warning on the charger after several hours of attempting to charge, and this after multiple attempts.
So a brief web search informed me that AGM batteries can be difficult to resuscitate if fully depleted. I'm wondering: do I have a bad battery?
It was installed only a month ago. Or am I not recharging the battery properly?
If it's truly a bad battery, I could have the dealer replace it (again), but I'd like to fix this myself if possible since getting to the Whaler dealer service department would involve significant amounts of free time which I do not have.
Any advice would be welcome. It should be fairly obvious to all that I know only enough about electronics to be dangerous.