VW T4 Forum - VW T5 Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
Hello. First time poster here so be kind. Does anyone know if you can use a 4gauge tinned ofc power wire as the main power lead going from your starter battery to your leisure battery via a split charger? I have a 2005 VW T5 LWB and it already has one installed and run through the van to power the audio system in the back.
If I could use that then it would save me much hassle in threading a new one through.
And then use another power cable to come off the leisure battery to power the audio system rather than run two cables from the starter.
Failing that...know a good auto electrician in the London area?

Thanks all

Lou
 

·
Registered
Joined
·
1,047 Posts
I over specced my wiring for safety and efficiency and have used 16mm2 cable from vehicle to leisure battery. 10mm2 is normal for 120A split charge relays.

I'm not sure what 4 gauge is, but on a quick Google, if I've found the right wire, it seems rated to 150A over 20', so should be better than some of the wire I've seen some use.

Is it protected in a flexible conduit, as you're putting a lot of energy through that with 2 batteries linked? Also, you'll need strip fuses of around no more than 50-80A on each end of the cable, as near to each battery as possible, so very little wire is left unfused.
 

·
Want Electrics? Go Wildebus!
Joined
·
8,166 Posts
Just for clarity ... OFC = Oxygen-Free Copper, which is the standard for any decent copper cable in fact.
4 (AWG) Gauge falls between the metric standards of 16mm2 and 25mm2 cable, so in terms of suitability for a typical split charge cable it would do the job.
Marcus, I would argue your statement that 10mm2 cable is the norm for a 120A VSR Setup? I think 16mm2 is much more common and if running over any kind of length (say battery is located at the back of the van) then 25mm is a better option. 10mm2 is really only used for a lower power B2B which will never deliver over say 40A. The cable has to be able to deliver both current AND minimise Voltage Drop, which is why the thicker cable becomes vital over a longer distance and higher currents.

FWIW, I swapped out my 16mm2 cable that was already fitted for 35mm2 cable to minimize the voltage drop as I can pull higher current with my setup then most installations
 

·
Registered
Joined
·
1,047 Posts
Marcus, I would argue your statement that 10mm2 cable is the norm for a 120A VSR Setup? I think 16mm2 is much more common and if running over any kind of length (say battery is located at the back of the van) then 25mm is a better option. 10mm2 is really only used for a lower power B2B which will never deliver over say 40mm. The cable has to be able to deliver both current AND minimise Voltage Drop, which is why the thicker cable becomes vital over a longer distance and higher currents.

FWIW, I swapped out my 16mm2 cable that was already fitted for 35mm2 cable to minimize the voltage drop as I can pull higher current with my setup then most installations
Yes, sorry, what I meant was the kits on Ebay with the Durite 140A relays will generally come with 5M of 10mm2. I wasn't keen on it being that low so used 16mm2 instead, although my leisure battery is under the drivers' seat, so the run is not too far. I power the fridge and a 12V socket from there with 6mm2, so used the supplied 10mm2 to carry power to the rear distribution panel which only powers USB, pump, 12V socket and lights.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #5
Hi All


Sorry for the delayed reply.


Thanks so much for your help and quick response.


Yes coming from the starter battery its protected in flexible conduit in the engine area and has also been fused with what looks like 32v fuse when it was installed (not by me and not when I've had ownership of the van).


I'll install another split fuse, one that came with the split charger pack before it goes into the split charger itself, to be safe.

My leisure battery is at the front of the van directly behind the drivers seat, so the cable isn't going very far at all.


The end of the cable though, needs to be redone anyway as the end is worn and damaged.


Once I've done that it should be just connecting up the leisure battery and away I go.


Thanks again. I'm sure I'll be on here for more T5 advice.


LouT:
 
1 - 5 of 5 Posts
Top