2011 GU8 ST 3.0 CRD, ARB Bullbar with IPF spotties, scrub bars and side steps, Snorkel, Dual Battery system, Waeco fridge, Turbo Timer, ARB Roof Rack with 5 IPF spotties across the front, Custom full Leather Bucket seats, DPchip, 3" Taipan exhaust, ARE Intercooler & scoop, Autron EGT/Boost and dual volt gauges, ARB front locker.
MEGOMONSTER (7th January 2014)
Finished reading one of Collyn Rivers' books on camper trailers and 12V wiring and immediately shortened my Fridge cable to bring the voltage drop back to an acceptable 0.11V. I was going to change the cable to 8B&S, but shortening my currently installed 6mm Auto wire was sufficient.
To explain - My fridge cable is 6mm auto cable (4mm2 of copper conductor), and I had 5 meters of twin flex running from the Aux battery to the fridge plug in the cargo area. This included a rolled up spare length of 2m tucked away in the rear quarter panel in case I ever changed my mind and wanted the fridge on the other side of the cargo area. My fridge cable is earthed back to the Aux battery, which effectively meant this was a 10m long circuit. By cutting off the spare 2m of twin flex, I effectively made it a 6m circuit.
I also have a single strip LED light running from the same circuit. Therefore total load when my 40 litre fridge compressor is running at full speed (~4 Amps) and the LED strip is on (0.3 Amps) is 4.3A. Lets call it 4.5A for roundings sake.
Therefore according to the equation to work out Voltage drop, 6m (conductor length) x 4.5A (load) x 0.17 (an ISO standard) = 0.459. 0.459 divided by the conductor area of 4mm2 = 0.11475. Apparently a voltage drop of anywhere from 0.1V to 0.15V is acceptable.
Prior to shortening my cable my voltage drop would have been around 0.19V, a little too high.
My joins are all soldered and the fridge plug is an Anderson plug. Theoretically there is probably some voltage loss in there somewhere too, but I'm not going to bother counting it as I think it would be pretty minor.
Anyway, thought some might find this an interesting exercise for their own vehicles.
Last edited by FNQGU; 8th January 2014 at 02:42 PM.
Between Patrols ATM. Had a beaut GU with 6.5 Chev TD. Next is a GU ute with a 4.5 litre Cummins conversion and a camper on the back.
Finally got the rear door diner from DCM customs on the troll, looks fantastic and when we went to port Campbell for a day trip I had a few admiring glances
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Pics brother...
Yeah, lower the better or you are effectively reducing usable capacity of your battery by whatever your voltage drop is.
Between Patrols ATM. Had a beaut GU with 6.5 Chev TD. Next is a GU ute with a 4.5 litre Cummins conversion and a camper on the back.
Got the turbo and inter cooler on just need to get it tuned now, it also has a very low whistle when she is on boost.
Last edited by Stropp; 11th January 2014 at 11:48 AM.
2003 gu3 td42tdi sold 😞 bloody gvm towing crap. Bt50 3500kg gvm.
Cleaned out all of the crap from two kids, two dogs and a wife after travelling from Albury to Innisfail and then on to Darwin, there was enough food hidden in places you thought you could never store stuff to have a three course meal.
PS Chey ran sweet as for 7400 km.
6.5 Chevy, roof rack, uhf, Spotties, dual batteries, ARB Bullbar, 12, 000lb winch, (unfortunately not Warn) Safari snorkel, Dieselgas conversion, 2in lift, engine watchdog fitted, boost/EGT guages, front elokka fitted, rear power supply mods, turbo timer, dual wheel carrier rear bar.
BigRAWesty (10th January 2014), Stropp (9th January 2014), Woof (11th January 2014)