Battery cable size

Battery cable size

Author
Discussion

Paulprior

Original Poster:

864 posts

104 months

Monday 16th May 2016
quotequote all
Hi
I changed my battery to see if it helped the very slow turn over when hot, but no change, so i guess i need to check / replace the cables, the main cable from the battery is a very fine cored very flexible cable, is this normal? what spec and size of cable should i be looking for to replace them with?
Also what is recomended for conections, at the battery mine are currently soldered directly into the battery lug
Thanks

Paul

carsy

3,018 posts

164 months

Monday 16th May 2016
quotequote all
Have a read here. Dave replaced his with 50mm cable.

http://www.pistonheads.com/gassing/topic.asp?t=110...

Edited by carsy on Monday 16th May 12:07

Paulprior

Original Poster:

864 posts

104 months

Monday 16th May 2016
quotequote all
Thanks for the very useful link, i just need to find somewhere to supply the cable now, 50mm sounds a good option.

I had also wondered about this hot start mod with the relaY, but dont see that that issue applies to me as mine is just slow turning over

Paul

carsy

3,018 posts

164 months

Paulprior

Original Poster:

864 posts

104 months

Monday 16th May 2016
quotequote all
Thanks for the very useful link, i just need to find somewhere to supply the cable now, 50mm sounds a good option.

I had also wondered about this hot start mod with the relaY, but dont see that that issue applies to me as mine is just slow turning over

Paul

QBee

20,904 posts

143 months

Monday 16th May 2016
quotequote all
With the thicker new cable the theory is you shouldn't need the hot start mod.

mk1fan

10,507 posts

224 months

Monday 16th May 2016
quotequote all
50mm!

Wow.

Using 25mm on my battery relocation.

bobfather

11,171 posts

254 months

Monday 16th May 2016
quotequote all
QBee said:
With the thicker new cable the theory is you shouldn't need the hot start mod.
The hot start mod is an improved power supply to the low current side of the starter solenoid. The starter solenoid and the starter motor are totally independent power supplies so increasing cable size to the motor won't help the solenoid to engage

Paulprior

Original Poster:

864 posts

104 months

Monday 16th May 2016
quotequote all
But if i dont have a problem with the solenoid engaging then the bigger cable should be the answer?

Belle427

8,858 posts

232 months

Monday 16th May 2016
quotequote all
I chose to run that 50 mm cable linked to through some 20 mm flexible electrical conduit. I cable tied the conduit to the heater ducting away from most of the heat at the back of the engine and down the chassis to the starter.
I drilled a new hole in the bulkhead area adjacent to the battery to fix the conduit gland in to, when it was in place i pulled the larger cable through with a smaller one.
Not too bad a job, the lugs for the ends will require crimping with a suitable tool for a belt and braces job. I hired one for a day from my local wholesalers.

FoxTVR430

452 posts

110 months

Tuesday 17th May 2016
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Belle427,
Do you have photos please smile

Belle427

8,858 posts

232 months

Tuesday 17th May 2016
quotequote all
I will take some later, not sure how much you can see now.

David Beer

3,982 posts

266 months

Tuesday 17th May 2016
quotequote all
Fit an additional earth braid from the battery negative to the first bolt on the block. Worked for many people. Halfords sell it

Paulprior

Original Poster:

864 posts

104 months

Tuesday 17th May 2016
quotequote all
So you recomend leaving the original earth and add a braided strap to the block, or replace the original as well?
Does anyone know the hole size for the crimps to fit the solenoid and starter motor, 6mm, 8mm?, just want to get them ordered ready for the weekend
Paul

Paulprior

Original Poster:

864 posts

104 months

Tuesday 17th May 2016
quotequote all
And how about cable length, from reading the threads I guess 3m of red is sufficient, how about the earth braided strap?

David Beer

3,982 posts

266 months

Wednesday 18th May 2016
quotequote all
Paulprior said:
So you recomend leaving the original earth and add a braided strap to the block, or replace the original as well?
Does anyone know the hole size for the crimps to fit the solenoid and starter motor, 6mm, 8mm?, just want to get them ordered ready for the weekend
Paul
Leave as is but add the cable.

Belle427

8,858 posts

232 months

Wednesday 18th May 2016
quotequote all
FoxTVR430 said:
Belle427,
Do you have photos please smile
Not a very good shot but you can see the idea. You can just see the conduit gland next to the heater pipes, its a bit awkward getting hands on that ducting to fasten the ties on it.


Shiersy

17 posts

103 months

Saturday 21st May 2016
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David Beer said:
Fit an additional earth braid from the battery negative to the first bolt on the block. Worked for many people. Halfords sell it
This worked for me , many thanks for the heads up, a bit of a struggle finding a bolt on the block that I could get to, but that's TVR's for you

Paulprior

Original Poster:

864 posts

104 months

Saturday 21st May 2016
quotequote all
How / where did you route the extra earth, i looked at mine today and it comes back and up to under the dash, but i have zero access from the footwell as its behind the fibreglass, i will remove the dash tomorrow to see if i can see where the positive cable goes, reading the threads about fixing a draw wire to use to pull the new one in wont work for me because my positive cable goes up through the underside of the dash through some rubber tubing along with the main harness from the ECU.
Is it not possible to route the cables straight out of the footwell somewhere?

Sardonicus

18,928 posts

220 months

Sunday 22nd May 2016
quotequote all
Paulprior said:
How / where did you route the extra earth, i looked at mine today and it comes back and up to under the dash, but i have zero access from the footwell as its behind the fibreglass, i will remove the dash tomorrow to see if i can see where the positive cable goes, reading the threads about fixing a draw wire to use to pull the new one in wont work for me because my positive cable goes up through the underside of the dash through some rubber tubing along with the main harness from the ECU.
Is it not possible to route the cables straight out of the footwell somewhere?
Thats what I done straight from battery - through corner of footwell with a grommet straight onto the engine block wink you can never have enough grounds/earth returns