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Old 06-28-2014, 10:07 AM   #92 (permalink)
serialk11r
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Quote:
Originally Posted by redpoint5 View Post
Have you measured the parasitic drain on your car? The Deka ETX12 only has 10Ah, of which probably only 4Ah is usable before you cause damage to it. It also weighs 12 lbs and costs a minimum of $40. I'd go LiFePO4 instead because it's much lighter, costs the same, and you can use most of the capacity without causing damage. It should last longer too.
Wow, at 70A draw for the starter yes a plain lithium sounds like it's probably good enough, certainly. What I was talking about was smaller capacitors however, for an additional layer of surge protection to the battery. For a car an appropriate quantity would be like a 70F bank, but for a motorcycle you could get away with way less.

I haven't measured my car, no. I'm guessing it's low because I don't have remote control key fob and no anti-theft alarm that I know of. Last year I went to Boston, asked my mom to start the car once in a while, which she didn't, and the car ended up sitting for over 2 months. Started up fine.

Sure the lead acid battery has only 10Ah (actually I think it's 14Ah), but an equivalent LiFePO4 battery would still be about 2x the price. Again, I'm trying to take into consideration the fact that batteries are supposed to be dropping in price. If the cost ratio is the same when this flooded battery dies, then I'm going for a small AGM. If lithium is down to 3x the cost for an honest equal nominal Ah rating, I'll buy that.
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