13500lbs winch - max size battery to fit tray?

I know what you mean. My SJ KJA would winch out most things, but as it was striped down for competition it was
only 950 KG so had to hitch the back end to a tree to stop it getting pulled forward.

I suspect its a bit like car speakers - they say 100w, but thats a peak output spec. the RMS reveals around 30w usually. so a 5900kg (13500lbs) winch is probably going to be straining to pull that load with any duration. The manual says to only go for 1 min at a time under heavy load, and as Rappey says, the layers of cable affect the load it can pull drastically.

Pulling a 1300kg jimny out of a bog or such will probably be more like pulling 2500kg (perhaps more?), if its dragging,
the snatch block will halve that to 1250kg if im worried about the battery. i have two snatch blocks so could halve it again even (if it works like that?).

As an electrician, i do have a 'clamp-meter' which can measure current draw through a cable, so i think a little experimenting with that is in order before trying to use it on an outing.

I would be very interested to know what current the winch is drawing ! Did wonder about fitting an ammeter just out of curiosity as some of us guys do love our toys and gadgets! Ive even looked at devices to measure the load in kg/kn on the rope out of curiosity, but omg the price makes it an expensive gadget to have !
We have bought budget chinese winches, so the claims of power consumption and even their max power rating may have to be taken with a pinch of salt !
Even the claimed breaking strain of the "dynema" cannot be proven, unless you can actually measure it.
Yes it does work like that if you keep adding snatch blocks, but then you may exceed the breaking strain of your rope or cable?

As a temporary measure you could carry a 2nd large battery in the boot and for £13 can get some 6m long ,claimed 1000 amps jump leads, then you can be happy that your starter battery will be unaffected ?

after dragging a disco out of a hole i cant ever see you needing to use more than a single line pull !

Its also worth thinking about rolling load as apposed to lifting capacity. In theory a 4000 lbs winch could lift a jimny
off the floor. I have a small portable winch that is only rated at 2000lbs. Its slow but has always got me out
of trouble when on my own. In the blurb that came with it, they stated 2000lbs lifting capacity but 6000lbs
rolling load eg towing a car or boat on the water. Best bit is its portable so can be fixed front or rear.
All for about £50.

I have this battery www.tayna.co.uk/Numax-CXV35MF-P8275.html in a Jimnybits tray and it is too tall and hits the bonnet as standard. I dealt with this by cutting a bit out of the bonnet strengthening structure - not a lot, just enough to give clearance. Otherwise there would have been a few sparks and a bit of a fire! I've also insulated the positive terminal with some rubber.

It is more than enough for my needs and has done a Winch Challenge and numerous heavy off road days with lots of single line pulls with no issues.

As such you would be fine with one of Numax's smaller batteries.

Mine is as good as the day I bought it and is a good 5-6 years old now. It sits for long periods of time unused. Often 2-3 weeks.

I got mine from Tanya batteries and they were good to deal with. The battery arrived dry with the de-ironized water in a container to add if I remember correctly.

I hope this helps.

Kirkynut

Note to self.....if ever offered some de-ionised water by Kirky say "I'm good thanks"


I have a 110ah 800cca battery under the passengers seat......great for electric blankets and electric fan heaters....jump starting cars......and weighing the car down!