Cranking batteries for o/b motor??

[Beck]

Hi to all,<br /><br />Just wondering if instead of one standard size cranking battery could I use (2) smaller batteries to crank my O/B?? The rear compartment for the batteries and gas tank would fit two smaller batteries easier with the standard deep-cycle than two full size batteries. If this is possible than what size smaller batteries (cranking amps) or I would just get the largest avaliable.<br /><br />Also if two smaller batteries are ok, which way would be best? (2) 6 volts wired is series or (2) 12 volts wired in parallel?<br /><br />Thanks,<br />Beck

 

[Silvertip]

Re: Cranking batteries for o/b motor??

Cranking amps requirement depends on how big the motor is. Regardless, two starting batteries in parallel (or 6V in series) creates another set of problems. Both batteries don't degrade at the same rate so the weaker one in a parallel setup will always draw the better battery down to the weaker level. A good quality group 22 battery will easily start most outboards and it is far smaller than two of any other type of battery.

 

[Beck]

Re: Cranking batteries for o/b motor??

Upinsmoke,<br /><br />I have a 48 spl that starts with the touch of a key switch. I'm now using a full size 12 volt battery that was used with 3 others to crank a diesel gen. 24 volts system. 3 of the 4 batteries were miswired and I wound up with the 1 good one left. The compartment for the batteries and the gas tank is rather crowded, thus why I was thinking of smaller batteries. I will look in to the size of a group 22 battery. <br /><br />My trolling motor battery is from a bank of ups battery for a computer room. Employer up graded ups system and anounced there were 50 deep cycle there for the taking. (saved them disposal fees) Needless to say they went quick.<br /><br />Beck