Generator Backup Battery

[Photolomy]

The marina decided to work on electric but never let me know, and I only find out once my 12v battery is dead and my boat goes offline. I have been meaning to put a second 12v battery dedicated to the generator, I did put a 2 bank charger in. Anyways, I ran down to AutoZone and bought one of these for $104 (and a $30 gift card back). And that little sucker started the (17kw) generator. Specs say 800A surge, 400A continuous.



Just an FYI.

 

[Boatsb]

As a start battery the new pure lead batteries dont loose charge like standard wet lead acid.

I have group 31 versions that are 2150 CCA short burst just for start use. Best choice for start batteries I've seen.

 

[jim rosenthal]

What brand are pure lead start batteries? That's something l might be interested in.

 

[Boatsb]

Northstar and Optima I believe are now the same company.

I have a single grp 31 starting a 425 hp 5.9 cummins easily.

 

[Photolomy]

This would seem like a market for LiFePo. Imagine 32v LiFePo capable of just starting our engines. They would be tons smaller than the banks we now have. Just high CCA, bot not high AH.

 

[Boatsb]

Maybe as a generator start but they are not designed for high amp draw needed for the mains.

 

[krush]

I have a single grp 31 starting a 425 hp 5.9 cummins easily.

When I upgraded the starter on my 8.3 cummins to gear reduction, the new grp31 $75 truck dealer battery (I think deka) started it no problem.

 

[Boatsb]

It should be able to start off a single group 31. The loss of power when off charge is a big difference with the pure lead AGM batteries. They have a very low loss of charge over time. They also have lower charge resistance.