Voltage drop from alternator to battery...

[Bassfiend229hp]

Anyone got any info on what's an acceptable voltage drop between an alternator and the battery?

I've got 14.7v at the alternator output and 13.7v at the battery positive in the boot ...

[blitzracing]

The voltage will be dependent on the current flowing into the battery when you measured it, so without a current reading as well the voltage drop has little meaning.

[Bassfiend229hp]

...only about 5 amps at the time - which seems high.

[blitzracing]

So 1 volt drop at 5 amps = .2 ohm, so nothing to worry about there then on cable resistance. A 5 amp draw would seem a little high on what should be a fully charged battery- but if its overcharging you will see the battery gassing, and the electrolyte level will drop. If its not dropping, then everything is as it should be.

[Bassfiend229hp]

She had just been started after being sat for a little while so she would have been a tad discharged so I guess was probably just charging and topping off the battery again...?