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Old 07-29-2014, 11:46 AM   #3
BigBo
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Join Date: Aug 2002
Location: RockVegas
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Ronnie, most electric motors are rated in lbs of thrust instead of hp. If possible, try to determine the amperage required at full throttle. For example, I have a 55lb thrust motor that draws @5 amps at low and 40-45 amps at full throttle. So now take a look at your battery and instead of looking at the group number, look at the AH (amp/hour) rating.
So if I have a battery that is rated for 45AH, that battery will only last one hour with my motor at full throttle. The trade off is that the higher the rating, the heavier the battery becomes (more lead plates) and as you probably already know, the price goes up.
The other problem is that lead cell AGM batteries, while a good bang for the buck, do not drain linearly. They get to a certain level and they go dead very quickly. And can only be recharged a given number of cycles.
There are other alternatives, but they get very expensive and when you're talking about getting out on the pond with the boy in a 12' tinnie, are hard to justify.
So, just look into a higher AH rating in a lead cell and go have fun with the boy.

The future ain't what it used to be. --Yogi Berra
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