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Old 06-20-2018, 03:57 PM   #11 (permalink)
Stubby79
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Quote:
Originally Posted by redpoint5 View Post
Not sure how that would work since starting requires several hundred amps. If I remember correctly, the BMS has a decent bit of phantom power draw too. If I'm undersizing the battery, I can't have large phantom loads.
You'd let the BMS control charging, and lighter discharging loads (like the rest of the car). You'd hook the starter wire direct to the battery's terminal. No worries about needing a big BMS, as long as it can handle the charging (and discharging, if used) amps.

Too many charging amps from the alternator for the BMS? Put in some diodes, so the battery can discharge as much as it wants, and a resistor to limit the charge current going to the BMS. Or a PWM current limiting circuit.

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