Max Current Drain For Standard 205/309

[boombang 2]

Anyone know how many amps are drawn when the car is starting?

 

i.e. not just the alternator, but fuel pump running too, dash lights etc.

 

I am getting rid of lots of bodged wiring and moving the battery to the boot in the process - just making sure I have accounted for enough of a draw!

 

4 gauge is running as the +ve through the master cut off, which then feeds 8 or 10 in two feeds as main lives to the fusebox, and another run of 4 gauge to a +ve "post" in the original battery position which does fans and starter and a couple of other bits in the engine bay.

 

Reckon I'll have to run another run of 4 gauge to the engine bay to a -ve "post" to then go as main earth to engine + chassis. And will also have another earth by the battery - worth it?

 

This is on an effectively standard 1900 8 valve, standardish compression and standard starter.

 

As its a rallycar is has a couple of extra bits of circuit but no spotlights or anything like that - all negligible bits.

[Rob_the_Sparky 9]

I have no idea what 4 gauage is but I hope it is BIG. Starter currents are in the hundreds of amps, no need to worry about anything else! Alternator current <90 amps and unlikely to be this big unless you have a larger than usual alternator. With the engine running power is drawn from the alternator (apart from tick-over with a high load perhaps) so cranking is what the cable has to be sized for.

 

As you are putting it in the boot I'd put in something at least 50% bigger diameter than the original, preferably more. Try a search, pretty sure there was a discussion about batteries in boots a while ago.

 

Rob

[Rippthrough 98]

I have no idea what 4 gauage is but I hope it is BIG. Starter currents are in the hundreds of amps, no need to worry about anything else! Alternator current <90 amps and unlikely to be this big unless you have a larger than usual alternator. With the engine running power is drawn from the alternator (apart from tick-over with a high load perhaps) so cranking is what the cable has to be sized for.

 

As you are putting it in the boot I'd put in something at least 50% bigger diameter than the original, preferably more. Try a search, pretty sure there was a discussion about batteries in boots a while ago.

 

Rob

 

 

I'd size it for a safe current of at least 500 amps, as the cranking current could be anywhere from 100 past 300 amps depending upon the motor, its age, the weather, battery condition, temperature, engine condition.....

Edited July 19, 2006 by Rippthrough

[boombang 2]

4 gauge is a bit bigger than the standard starter and should be adequate.

 

I found the other topics but nothing about actual cable size - just it says you need BIG cables. This stuff ran my old chavvy stereo (genuinely over 500 WRMS) and never got hot.

[Rippthrough 98]

4 gauge is a bit bigger than the standard starter and should be adequate.

 

I found the other topics but nothing about actual cable size - just it says you need BIG cables. This stuff ran my old chavvy stereo (genuinely over 500 WRMS) and never got hot.

 

 

A starter motor could be drawing 2kw continous though.

[boombang 2]

Surely in that case it would burn out the standard cabling which I believe is 6 gauge?

[Rippthrough 98]

Surely in that case it would burn out the standard cabling which I believe is 6 gauge?

 

 

Check the starter motor model, most are between 1-2kw. Not sure on the exact draw for your unit. If the standard is 6 then I'd say you *should* be OK with 4 guage.

Edited July 19, 2006 by Rippthrough

[Super Josh 4]

The standard GTi starter is around 8 - 900 Watts and the diesel one around 1.8 Kw. 4 gauge doesn't seem butch enough to me, especially considering the long run to the boot. I would be looking at 2 or 0 gauge.

 

 

 

Josh

[jonnie205 1]

i would use a quality 25mm squared cable

 

this is rated for about 350 amps continuous which is important as its peak rating is much greater ( you get about 20secs at peak rating which is perfect for cranking )

 

you have to take into account voltage drop with a long cable run, once routed you can easily need 4m of cable depending on battery location

 

a new starter pulls in the region of 200 amps on cranking