Spare battery

[Seashoreman]

I have a new car battery, 55amp (I think). Was wondering, if I charged it and stored it on the boat as a back-up for emergency use would it hold its charge for a season? Have 110amp main and smaller starter on the go which both work well for my use. Just a thought?
(Could do with a bit of ballast on port side, Leisure 23sl. Main locker, batteries, table, beer store, heads and my favourite reclining/ sleeping situations are all on starboard side of boat, I list a little at anchor. I personally find this humourous but wonder if passing serious sailors think I am a little unbalanced?)

 

[sailorman]

I have a new car battery, 55amp (I think). Was wondering, if I charged it and stored it on the boat as a back-up for emergency use would it hold its charge for a season? Have 110amp main and smaller starter on the go which both work well for my use. Just a thought?
(Could do with a bit of ballast on port side, Leisure 23sl. Main locker, batteries, table, beer store, heads and my favourite reclining/ sleeping situations are all on starboard side of boat, I list a little at anchor. I personally find this humourous but wonder if passing serious sailors think I am a little unbalanced?)

you get a set of jump leads & charge off of your existing batteries when under engine

 

[William_H]

As said it would be far better to recharge it occasionally by connecting to either engine or domestic battery. Just leaving it sit there will not help it's long life. Or you could wire it in pernanently in parallel with doemstic battery to kep it charged plus make domestic last longer by reducing discharge %. For me powever I try not to load the boat up with unnecessary stuff. So I would try to ballance the boat by moving essential stuff and leave the battery home. You have one standby battery that should be enough. good luck olewill

 

[vyv_cox]

I left all my batteries disconnected from each other and not charged mid July last year, due to bringing the solar regulator home from Greece for repair. At the end of April this year, i.e. more than nine months, all four batteries showed 12.5 volts plus.

 

[VicS]

you get a set of jump leads & charge off of your existing batteries when under engine

Some fixed wiring with a switch to link it to the existing would be preferable.

There is always a risk with jump leads that a spark when connecting or disconnecting could ignite any hydrogen gas which has been produced.

The probability is low but the consequences of battery exploding less than an arm's length from your face could be very unpleasant.