This is the 950cca battery I was talking about http://www.exide.com.au/battery-rang...mercial/31-950 (http://www.exide.com.au/battery-range/motorcycle/heavy-commercial/31-950) Length:328 mm Width:172 mm Height:240 mm pretty small just bit larger than n70zzmf @ only 730cca

Anyone that runs a ground lead from battery to block is wastin time and money, use the big enuf cable (at least 35mm square) and u wont have a drama, one from battery to boot floor and other from k frame to block.

Whilst I have optimas in both my vl's they will start off a 12ah bike/jetski style battery. It's all about voltage drop

Quote: Originally Posted by JET-64U [View Post] Anyone that runs a ground lead from battery to block is wastin time and money, use the big enuf cable (at least 35mm square) and u wont have a drama, one from battery to boot floor and other from k frame to block. Considering the number of threads posted on CT with problems after putting the battery in the boot, i don't think it's a waste. If it's all about voltage drop, why are you relying on ****ty joins between bodywork. Thats where the biggest voltage drop is..... Big power cable is useless if the ground connection is sh!t.....

Yeh mate I've only been an auto elec for 10 years And never done battery relocations let alone start systems on 800ton excavators with twin 75l motors, it's on ct it must b right

Quote: Originally Posted by JET-64U [View Post] ......it's on ct it must b right I never mentioned anywhere that my suggestions were based on info from CT. I was stating that there have been plenty of posts on here complaining of poor starting after a battery relocation. Where guys have then ran a ground cable, the problem was fixed. My suggestions were based on 15 years experience in the electrical engineering industry..... I don't doubt that you will get away without a battery to boot cable some of the time......it all depends on the continuity between the 2 connection points in the bay and in the boot......but for the sake of an extra $50 in cable i know what i'd be doing.

Quote: Originally Posted by JET-64U [View Post] Anyone that runs a ground lead from battery to block is wastin time and money, use the big enuf cable (at least 35mm square) and u wont have a drama, one from battery to boot floor and other from k frame to block. 35mm2 cable is pretty small compared to what most people run in these setups.. its like 220amp cable or something I would be running 50mm2 or 70mm2 in my own project. Which is 315 or 400amp cable Unless you are just running under 500amp cca battery I would use the big stuff.

Electrical engineering, woohoo go fix an Ac electrical motor or flick a circuit breaker when somethin doesn't work, another engineer like the ****s I deal with at work everyday, unless ur Vl is a rust bucket ur body of ur car will carry more current than any cable

Maybe u guys should stick an ammeter on ur start lead when cranking and see Wat they actually draw, funny how higher compression turbo diesels etc are lucky to have 10-16mm square cables in them

Just cuz u have a 500+ cca battery doesn't mean that's Wat ur starter draws

I had the same problem. Bought myself an Optima RED Top with 800CCA and problem is sorted. They are pretty pricey tho.

Lulz @ Jet, nothin against you bro n i don't know much about electrical stuff myself but, Monsta has posted quite alot of useful stuff over the years and knows his sh!t so i wouldn't be so quick to bag him like that..he is a big help around here! ..'Can't we all just get along' Some original photos have not been recovered yet.

Deffinately mate, Wat I think is funny is I'm an auto elec by trade, I do this **** all the time on 4 million dollar dump trucks and big diggers, a 793 cat dumptruck comes with 70mm start cables standard with two 11kw starters on it and u guys are sayin to use 50mm, the only thing I would consider using 50 on would a high comp v8 or somethin, any decent 35 mm cable is rated at around 300amp continuous, most older Vl starters are 2.6kw which is high compared most gear reduction Versions, not sure if u need to go back to school but @12v that starter will only draw 216amp, even it initial stall when u will get a spike you still easily do it with 35mm, another thing to consider if anyone intends on doin any proper racing is weight difference, that is all

And I was only trying to help to. Everyone's a genius when it comes to Internet forums

Totally agree with the cable sizing comments. I still think you are under estimating the impact of a poor earth. If the starter is 2.6kW then its internal resistance is somewhere around 0.05 ohm. So if you had a poor connection between the battery & starter that resulted in a resistance across that connection of 0.05 ohm (entirely possible when using the body as a conductor), the voltage divider rule means you are dropping 6v across that join and seeing only 6v at the starter........ No need for a personal attack on the engineer. I design cable systems & switchboards for large industrial plants on a regular basis. Not your pissy 70mm cables but multiple 240mm cables per phase, so although i'm not an auto lecky, i think i'm pretty well qualified to comment on the subject.

My bad I was thinking 35mm2 was only 215amp but that was 25mm2 I only went to 50mm2 cable because I was running it over distance.. plus it was like $3 a meter more so why not. Until I cleaned up my wiring under the dash I had crap earths so I had to run an earth up the front of the car to get a good start, even tho I allready had it earthing at two body points in the boot.