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Old 12-16-2017, 02:51 PM   #16 (permalink)
redpoint5
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Quote:
Originally Posted by serialk11r View Post
On a car that comes with a bigger battery/alternator/starter, I would probably put two of those together for 40Ah.

Supposedly some LiFePO4 cells can take charging at maybe 25F but not much below that, if you have cold winters I think it is smarter to run lead acid.
I wouldn't get larger/multiple batteries just to provide enough cranking amps to the starter, or to absorb large alternator currents. The solution to either too much cranking draw from the battery, or too much charging from the alternator would be to run supercaps in parallel to the battery, and placing a high watt, low ohm resistor between the battery and supercap. This would limit draw/charge on the battery, and offload big spikes to the supercap. It would also allow the battery to be moved inside the vehicle using relatively thin gauge wire. Moving the battery inside the cabin would help regulate temperature, and make it more convenient to disconnect and put on a charger if you wanted to run an alternator kill switch.

Here's a poorly done video I made explaining the battery/resistor/supercap concept.

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Last edited by redpoint5; 12-16-2017 at 02:57 PM..
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