So I inadvertently killed the power...

[old_timer]

So I inadvertently killed the power to my 2012 310DA the day I left for. 2week vacation.  Not sure what to expect when I return.  Still in vacation.  Will year old batteries be dead?  If dead can I simply plug in and let the battery charger recharge them?  If dead does Merc vessel view have to be rebooted?  Ugh!!!

[wingless]

The battery state of charge when power is eventually restored will largely depend on the applied load.

The largest load is frequently on the house bank, from the refrigerator. A 2-3 day run time is common on the house bank.

Proper care and feeding for batteries is for them to not be stored for extended periods at State of Charge below 75% to limit the permanent battery damage of plate sulfation.

It is probable that the discharged batteries will have decreased capacity, but probably acceptable performance.

The typical threshold for end of life is when the battery capacity drops below 50% of the nameplate rating.

[old_timer]

Wingless, i should have been more specific, I had turned off all circuit breakers, and (dc and AC) the only drain, I think, was for the battery charger and bilge pump. But then I popped the circuit breaker to the power to the boat. So the charger was not working and the batteries are just sitting. What do you think? Dead?

Sent from Gbt

[wingless]

Those year old batteries that started fully charged, w/ the only loads applied being infrequent bilge pump operation, the CO detectors and any other small parasitic loads should be fine.

A healthy idle battery has about a 10% self discharge per month.

After 2 weeks w/o trickle charge these should be almost fully charged.

Prior to restoration of power it would be interesting to measure / record / post the DC voltage readings for each battery bank.

[old_timer]

Ok, with voltmeter?

Sent from Gbt

[old_timer]

Wingless, I just got back from vac. I did not turn power on to the boat, in order to measure batteries after 2+weeks without any drain or charging. I knew I had some power when the hatch lifted normally. All four read 12.80/12.90. What a relief!!!! Thanks for the help.

[wingless]

Great news. Thanks for the info and for the update.

[Midnight_Run]

I would check the water level in all batteries if they are lead acid maintenance batteries and fully charge before attempting to start an engine.