Buck Turgidson
Well-known member
So I left the boat switched on last year and by the time I realised and got back to her the house battery was dead. On the solar controller it showed that it had been cycling between 4 and 8 volts for about a week.
I put the shore power and engine on and re charged whilst I monitored its temperature ready to stop at the first sign of trouble but it took all the amps I could give it . After a couple of hours I took the charge off and monitored the voltage on the terminals . Quickly dropped to 12.5 then over an hour with no load dropped to 12.2.
I decided it was dead but put the shore power charger on at storage mode . Slept on the boat then checked the battery temp and condition in the morning. It looked normal and was cold. So I left it like that.
3 months later:
Got to the boat and turned off the charger and turned on the boat systems plus plugged in a few extra loads(phone and iPad ) so I had a load of 3-4amps.
Battery dropped to 12.35 indicated which is about 12.5 on the terminals it then over the next 2 hours increased to 12.5 indicated and stayed there for the next 2 hours!
Chemistry was clearly happening but I don’t know much about that.
Charged it up overnight using normal bulk float storage values and then went sailing for 30 hours.
The battery appears to be functioning normally and now settles at 12.7 volts
Now clearly this isn’t the same as doing a proper drop test and I did have the engine on after about 12 hours but at that point the volts were good at 12.5 indicated
Arrived and switched everything off yesterday and the battery is sitting at 12.7 with no load .
EDIT: battery is an Odyssey extreme PC1800 FT
I had already bought everything I need to switch to a new lithium except the battery itself and it looks like I can postpone that for now.
I put the shore power and engine on and re charged whilst I monitored its temperature ready to stop at the first sign of trouble but it took all the amps I could give it . After a couple of hours I took the charge off and monitored the voltage on the terminals . Quickly dropped to 12.5 then over an hour with no load dropped to 12.2.
I decided it was dead but put the shore power charger on at storage mode . Slept on the boat then checked the battery temp and condition in the morning. It looked normal and was cold. So I left it like that.
3 months later:
Got to the boat and turned off the charger and turned on the boat systems plus plugged in a few extra loads(phone and iPad ) so I had a load of 3-4amps.
Battery dropped to 12.35 indicated which is about 12.5 on the terminals it then over the next 2 hours increased to 12.5 indicated and stayed there for the next 2 hours!
Chemistry was clearly happening but I don’t know much about that.
Charged it up overnight using normal bulk float storage values and then went sailing for 30 hours.
The battery appears to be functioning normally and now settles at 12.7 volts
Now clearly this isn’t the same as doing a proper drop test and I did have the engine on after about 12 hours but at that point the volts were good at 12.5 indicated
Arrived and switched everything off yesterday and the battery is sitting at 12.7 with no load .
EDIT: battery is an Odyssey extreme PC1800 FT
I had already bought everything I need to switch to a new lithium except the battery itself and it looks like I can postpone that for now.
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