Questions About Battery Relocation To The Boot

[Atari Boy 11]

I am slowly getting together the parts I need to move the battery to the boot of my 205.

I have got a very nice BMW distribution block and have just ordered a bulkhead conector etc.

 

I plan to use 25mm² cable which is rated up to 170 amps. I want to fuse the battery but am not sure what would be an appropriate fuse capacity.

 

Any ideas?

 

 

Many thanks

 

Jonny

[DrSarty 90 1 Cars]

I would say a 60amp fuse would be plenty.

[Tom Fenton 1,548]

I would say a 60A fuse will blow the first time you try and start the car.

 

Some manufacturers fit a fusible link to achieve protection of the main battery cable. However to be honest it should be routed and clipped so that it can never chafe through the insulation, and hence not need a fuse.

[DrSarty 90 1 Cars]

The fuse is a precaution. The grommeting of any cables is a must.

 

I'd like to see if a 60amp blows, but I doubt it will. Happy to be proved wrong of course.

[Galifrey 1]

The fuse is a precaution. The grommeting of any cables is a must.

 

I'd like to see if a 60amp blows, but I doubt it will. Happy to be proved wrong of course.

 

Starter motor draws 60-150 amps depending on temperature... It will last 1 key turn

 

[DrSarty 90 1 Cars]

Starter motor draws 60-150 amps depending on temperature... It will last 1 key turn

 

Perhaps a high current circuit breaker would be a better idea then? It could also act as an immobilisor and save current drain when the car was parked for extended periods.

 

Remember though that a 60amp fuse doesn't blow the instant it sees 60amps; it needs sustained exposure.

[Galifrey 1]

Perhaps a high current circuit breaker would be a better idea then? It could also act as an immobilisor and save current drain when the car was parked for extended periods.

 

Remember though that a 60amp fuse doesn't blow the instant it sees 60amps; it needs sustained exposure.

 

60-150 amps is free current draw, will be closer to his 175 amps while cranking and potentially much higher on a cold day with thick oil...

 

Come to think of it, maybe 175 amp cable is gonna be getting warm

 

[DrSarty 90 1 Cars]

Come to think of it, maybe 175 amp cable is gonna be getting warm

 

Gonna have to disagree with you Mark.

 

I've worked on 2 of my mate's Beemers and they have cable no larger than 4 gauge (25mm^2) going from the OE rear mounted battery to the straight 6 lump several metres away.

[Galifrey 1]

Gonna have to disagree with you Mark.

 

I've worked on 2 of my mate's Beemers and they have cable no larger than 4 gauge (25mm^2) going from the OE rear mounted battery to the straight 6 lump several metres away.

 

Twas meant to be humour rich.... wooooooosh!

[DrSarty 90 1 Cars]

Twas meant to be humour rich.... wooooooosh!

 

I've been travelling mate. Now back in Kabul.

[Galifrey 1]

I've been travelling mate. Now back in Kabul.

 

 

[Atari Boy 11]

I want to do a proper job and I don’t want to kill myself so all comments welcome.

I am going to use one of THESE for the bulkhead instead of a grommet. I have found an OE clock blanking plate and will mount a master battery cut off switch there instead, as the car is not used every day and it will prevent current drain.

 

So back on topic, what fuse and cable should I use?

 

Thanks chaps

[jackherer 543]

Perhaps a high current circuit breaker would be a better idea then?

 

They're available with high enough ratings but they seem to be extremely expensive.

[Galifrey 1]

I want to do a proper job and I don’t want to kill myself so all comments welcome.

I am going to use one of THESE for the bulkhead instead of a grommet. I have found an OE clock blanking plate and will mount a master battery cut off switch there instead, as the car is not used every day and it will prevent current drain.

 

So back on topic, what fuse and cable should I use?

 

Thanks chaps

 

Those look good, 170amp cable should be fine, no fuse is my recommendation, but run the cable sensibly.

[pablo 0]

maplin do (or did) 100A circuit breakers. you kinda need one each end though to be safe.

Edited December 6, 2009 by pablo

[pugpete1108 62 1 Cars]

i've used a bmw cable on my battery in boot and have not used a fuse (there wasnt one when fitted to the bmw so its good enough for me )

 

well protected through the bulkhead though