Thread: Jump start points outside battery box

Totally agree with the Anderson plug next to the seat. I use a 175 A plug which fits very neatly.
But there is a problem with 'normal' jumper leads often being too short to go from the centre of the defender to the 'donor' battery. Or vice versa if starting another vehicle.
My fix has been heavier cable (welding leads) to anderson plugs front, centre and back. Added a switching relay and large fuse. Powers a winch front and back (used to winch out backwards or for a winch on a trailer). And can jumpstart - or be jumpstarted - from front, centre or back.
Works a treat.

Telling any one to use an under rated fitting to do any job is just about criminal. You have a potential of up to 700CCA in most heavy duty off road 4x4 batteries that you some how think is fine to pass through a 50amp fitting. Even accounting for "leave it to charge awhile before cranking" can NOT guaranty that the disabled vehicle does not have a dead cell or two in its battery and will pull an insane amount of amps to try and start the dud. Always remember you must protect YOUR vehicle first and foremost before worrying about the lame duck. You are of no help if in trying to help you break your own truck. That goes for ANY type of assist, be it a jump start to a tow or even a recovery (winching).

The smart approach is to look for the amp rating of your jump cables (most tend to be around the 400A mark) so this is what we need the fittings on both ends to be able to handle. Now IF you can't find a 400A plug/socket/Fittings and can only find say 350A types, then down rate the cable to 350A and FUSE it for THAT. A nice big FAT HRC (High Rupture Capacity) type fuse or Circuit Breaker (marine types get up-to around that much) on your end of the hook up. We aren't concerned about the lame duck, its already lame, what we want is to not add to the situation and burn your truck down to the ground all for the want of a few correct fittings.

You can run multiple jump hook up points say to front or rear, so long as its protected correctly. I would also suggest a Single Pole Battery switch on this cable run right before the Fuse/CB which can then run to a set of HD bus bars (again from a marine shop) so as to allow for as many points as your heart desires around your truck. The switch is more for your own safety if you have an accident so this way you wont have a live high amp fitting arcing out in side all that mangled metal/aluminum.


Edit: Links.
HRC Fuse Block:Blue Sea Systems, Fuse Block, DC, Class T, 225 - 400 Amp

Fuse to suit:Blue Sea Systems, DC, Class T Fuses, 20,000 Amp Interrupt Capacity

Now don't let the 20 000 amp interrupt scare you. That's a MAX FAULT current rating that it can withstand. Every time a fault current is produce it has a MASSIVE spike for the first few milliseconds. That's what its referring too. These are available from 200-400Amp continuous use fuses. Perfect for Jump Starting and indeed winching.

Originally Posted by Hugh42732

... Same as found on our farm tractors / harvester, which provides power to fuel trailer pump when refuelling. I'd be happier with an insulating barrier betwixt the posts to obviate clamps rotating / shorting. Or further apart. An isolated or removable link if you park in dodgy neighbourhoods!

Originally Posted by gruntfuttock

Hello everyone,
i am a bit over the idea of getting my wife to get out and pull apart the seat every time I need to jump-start some one. (Yes i know i can just drive past like everyone else, but i’m Not like that). Ive been thinking is there anyway some kind of connection could be put outside the battery box. ? Anyone got any ideas?

I was thinking of something like large bolts and I inserting a nut into a piece of nylon round stock to stop the risk of shortage on the positive side but unsure as to what would be a strong enough insulator, or even if it is possible?

Just throwing an idea up, and seeing if it comes down with some fruit, or gets blasted away.

Thanks

my New Disco has started battery in rear cargo area. there are 2 OE points in engine bay to click on jump starter cables. as an aside, my transportable large LFP battery pack (200aH AGM equivalent) I use as my 2nd battery has Anderson 175A connectors as well as usual 50A rated... used for camping..run fridge lights etc. there are even larger Anderson connectors I believe

I have a set of ARB jumper leads that come with monster clamps and a 175 amp Anderson plug on the other end. The kit includes a short lead with cable lugs on one end and Anderson plug on the other end. I have the + cable wired to the dead side of an ARB winch isolating solenoid, so it is "dead" when connecting. The short lead is just loose under the bonnet, but could be permanently mounted if required.

Have to agree about using small plugs and BS cable though!

Originally Posted by Gibs

Telling any one to use an under rated fitting to do any job is just about criminal.

Hi Gibs and sorry to be so abrupt, but you REALLY have no idea what you are talking about.

I have to be honest, I only got a few lines into your reply and gave up.

If a person carries out a JUMP START correctly, there is no need for anything bigger than 6B&S ( 13.5mm2 ) Jumper cables, connected through 50 amp Anderson plugs, with a 50 amp auto resetting circuit breaker, mounted inside the Defer battery compartment.

Try reading the info at this link.

On-Line auto electrical info

Hi again Gibs and I have just fully read your reply.

Mate, you really need to get an education in this field before you make statements like yours.

For a starter, ( pardon the pun ) you are obviously of the OPINION that jump starting a vehicle is similar to winching.

The cable needed for a 400 amp winch operation needs to be at least 5x thicker than the cable needed for a 400 amp jump start.

The reason is that one is based on a CONTINUOUS load while the other is virtually an INSTANTANEOUS load of just a few seconds.

6B&S cabling will easily and SAFELY handle 400 amps for a few seconds, and if supplied through a 50 amp auto resetting circuit breaker, the circuit breaker will not trip during the jump start.

I have some massive jump leads on about 6 m of cable (probably B&S 0000 or about 140 mm2). Yes some overkill. Most commercially purchased jump leads even the heavy duty ones don’t go much above 35mm2 or around B&S or AWG 2. For jump staring over a couple of meters and for a short sharp crank a B&S 6 will do. Mind you I have a B&S 6 running from front to back to connect aux battery in rear compartment of a D2 to the alternator up front. Fused to 50 Amp on 50 Amp Anderson connectors. I’d chance a jump on that setup from the aux to the starting battery.

Any more is really for heavy continuous currents over minutes not 1or 2 sec max as per a jump start.