E34 starter motor current drain

[ktteoh]

folks, 2 questions:
1. what is the max current drain of the starter motor during cranking?

2. is there a fuse that protects the starter motor circuit - where is it and what is the ampere rating?

[yaofeng]

Can't answer 1 but the starter motor is not fused.

[pingu]

Several hundred amps? More if it's cold (and the engine is hard to crank)?

[Ferret]

At cold on such a big engine, while the starter motor is in stall and voltage applied, it can draw upto 450 ish amps instantaneously.

It IS CATEGORICALLY NOT feasible to use that trunk cable.

[ryan roopnarine]

IIRC the entry in the etk is for "starter, 1.8 kW", so whatever 12 and 1800 is by ohm's law.

[Ferret]

IIRC the entry in the etk is for "starter, 1.8 kW", so whatever 12 and 1800 is by ohm's law.

1.8kW continuous = 150Amps...
However that will spike massively while the motor's stalled.

[bones]

ferrett,i just moved my battery from the engine compartment to under the rear seat.im hearing all kinds of cautions about the 4 guage wire that is allready there being to small to carry the load.the factory used a 2 0t positive cable in the engine compartment and then used a 4 ot to ground the battery to chassis.the circuit cant handle any load greater than the 4 ot ability to ground the circuit.is this correct?.bones

[bmwrp8]

ferrett,i just moved my battery from the engine compartment to under the rear seat.im hearing all kinds of cautions about the 4 guage wire that is allready there being to small to carry the load.the factory used a 2 0t positive cable in the engine compartment and then used a 4 ot to ground the battery to chassis.the circuit cant handle any load greater than the 4 ot ability to ground the circuit.is this correct?.bones

could you post a pix of the battery under the rear seat and what it looks like now on the engine bay?? I'm thinking of doing this also if its not that hard.