Minimum Battery Voltage to Start Car?
 

What's the minimum battery voltage to start the R? Or is it amps? I'm not sure if I can measure the amperage of the battery with a voltmeter. My battery may be going bad because it's such a garage queen, but I'd like to know whether I can bother to attempt to start my R the next time, or just charge the battery. I'm getting 12.55 volts fully charged. Are you guys with stock batteries getting higher voltage? My WRX is 12.78 volts, but it has a much bigger battery.

Re: Minimum Battery Voltage to Start Car? (WTypeRogerX)
 

From the Car Battery FAQ below, 12.55v is approx. 90% fully charged.

http://uuhome.de/william.darden/carfaq4.htm

Re: Minimum Battery Voltage to Start Car? (WTypeRogerX)
 

i think it amps and depends on the weather, - why my stock battery died, it showed signs before it dropped to cold temps (lights dimming in/out), it measured at ~ 360cca and would not start the car in cold weather.

Re: Minimum Battery Voltage to Start Car? (WTypeRogerX)
 

I would guess 9 volts would probably start it. 10 volts definatly would.

Re: Minimum Battery Voltage to Start Car? (jond)
 

9-10 volts equals 1 bad cell in your battery.

Voltage does not really matter, it is the AMPS that deliver the power to start the car.

All the stuff inyour house runs on 120volts, but the big stuff, like your blender, furnace, etc draw far more current (amps) at the same voltage. voltage=amps*resistance.

I don't know the exact # for req'd amps in your battery to start your car, but you should be ok w/ 12.5 I think. Check w/ the voltmeter when the car is running across the terminals of the battery- it should be reading 13-14 volts because it is charging.

If not, replace the battery or alternator. (at a shop if you are not sure even on how electricity works) Batteries are like 50 bucks.

Re: Minimum Battery Voltage to Start Car? (WTypeRogerX)
 

how about just enough to get a spark https://honda-tech.com/forums/images...s/emsmilep.gif