12v Extension leads

Depends on the current draw. How many amps does the gear draw?

There is a useful calculator here:

http://www.energymatters.com.au/climate-data/cable-sizing-calculator.php

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There is no limit to the length, but for a given current the wire diameter needs to increase as the length increases. Losses in the cable mean losses to the delivered volts to the appliance which should be limited to no more than 0.5 volts. The wire also needs to be big enough to not overheat and cause damage.

Not hard to calculate the necessary cable size if the length and load is known but if we assume your maximum current is 10 Amps and the length of the cable pair is 10m then a cable size of 8 AWG would serve OK.

If you were to increase the length to say 20m then you would need a cable of twice that size which would be 6 AWG.

I've got the same HWS. I'd be a little cautious of using the car battery directly - once the pump came on/ off as it's meant to and after having a full battery (just driven 300km's) the battery was dead flat within 5 minutes. That sounds like a problem somewhere with the Joolca, granted, but it left me having to charge a V8's battery for an hour from a jump-starter module for enough cranking power.

I now have a RAPS system that I use exclusively for the HWS. I see Anaconda at the moment has a 40Ah Lithium battery pack, with Ciggie, Anderson, USB etc ports as well, going for $599 and it only weighs 6.5kg. For all the other various things this could be used for, I am going to get one of these and, again, have the HWS using this power so it's separate from the cars main battery.

I don't have a dual system, so perhaps this isn't an issue. I prefer the portability of these battery packs myself.

I bought a 5 tonne 12 V electric/hydraulic jack to jack my car (I have sever respiratory problems and have trouble jacking a car if needed), The lead on the jack was long enough to reach all the wheels on my Pajero, but not to reach the caravan axle, so I bought a 12 V extension lead from Ebay. I selected on which was supposed to be rated for 15 amps (they didn't say over what length though) and it jacked the caravan fine. Then I used it to run the air compressor and it blew the fuse in the plug. When I pulled the fuse out, it was only a 5 amp fuse, so I had to then go out and find some of the old style glass fuses and fit a 15 amp fuse into the plug. All good now

Anything like this, I make them up using Anderson plugs plus using reasonable size wire, e.g. to run a compressor.

Hi Marsa
If you have not got the gear to make up a 12v. extension lead a phone call to this Person will put you right.
andersonconnect.com.au

If you are going to the trouble of making up an extension lead you may as well male it as heavy duty as you can to cover future loads.

We power our Tvan from batteries in the tow vehicle. Water pump, led lights, radio & a sirocco fan, plus an inverter to power my laptop.
The cable is 13mm2 (6B&S) & almost 10 metres long. Works OK, but still gets significant voltage drop when charging the laptop (7amps) - the voltmeter in the Tvan drops to around 12v whilst the one near the batteries still reads over 13v. (mind you there is probably 2 or 3 metres of original Tvan wiring after the extension cable which is lighter than the extension cable). Not an issue for us as we have plenty of battery & solar. 10 metres of 6B&S twin cable is not insubstantial & fairly heavy weight wise but is a good compromise for us. Going for lighter cable and/or greater length will see more voltage drop but if it gives you enough at the pump end to run the pump & you can easily re-charge that may suit you. .... but I reckon 10metres of 6B&S twin core with an andersen plug each end will be more versatile in the long run.

You're right Cuppa,
My heavey duty extension is used for suitcase solar panels, compressor to reach all wheels, power to a campfire light on a tripod .
Cheers