13500lbs winch - max size battery to fit tray?

Please have a look at my signature.
I'm not exactly new to winching. Probably use it more than most on this forum do.

You need to understand that a 13000 lbs winch does not draw anywhere near 420 amps under low to medium load.

But I can tell you this.
My setup consists of 2 bow1 motors, 2 Varta AGM 80 Ah 800 CCA batteries and all cables not under 70 mm2. I'm very well aware of what kind of amps a winch CAN draw from a battery.

My comment was on occasional winching out of a ditch or something like that. it doesn't draw very high current, so is fine to use until money's there for a bigger battery.

I have had boats, lots of them and work in the marine industry.. battery's play a big part.. charging via solar, wind, alternators/engines, generators etc... understanding battery's themselves is important.. especially when it comes to discharging and recharging.
A standard lead acid starter battery is designed with one purpose, to take a huge hit when starting an engine for a small amount of time and to be recharged quickly.. They say that you should not take more than 25% of its charged capacity otherwise you are diminishing the life of the battery. If you deplete its charge beyond what is recommended 12 times then the battery is junk as it will never hold a decent charge again.
A deep cycle or leisure battery is designed to have up to 75% of its power used before needing to be recharged... but not so good at high drain loads.. More suited for prolonged discharge over time...
Yes there are battery's that are leisure/deep cycle that are also suitable for cranking.
Point being, stock 40 amp jimny battery operating a winch under any load will take more than 25% of its charge in no time at all, damaging it, its just a matter of time before you kill it beyond any recovery.

Many modern battery's have ever thinner lead plates, leading to more premature failures.. many motorbike battery's if left to completely discharge can never be charged again....

Yes i know the 420 amps is only when under max load, but at 80+ amps with zero load im sure the current rapidly rises with a light load.

OK, Thanks for the argument, I can see that you both are very knowledgeable on batteries.

From the manual of the winch:

0kg load = 70 amps
1363kg load = 138 amps
2727kg load = 218 amps
4090kg load = 260 amps
5900kg load = 330 amps

So as Tom says, it will suffice with my current 400a battery, snatch block, etc as is provided i dont try to winch anything other than my own vehicle's weight (max), very occasionally.

If i were to be using it for recovering a heavier vehicle or competition use then i would look at a dual battery setup as Rappey has. This because of problems with sourcing a AGM battery for a jimny, i am strugging to find one small enough to fit into the tray. i would prefer not to have to have a second battery if possible.

When i wound the rope onto the drum i did it with the engine off and on standard battery. it didnt sound like it was struggling at all with pulling the rope in (with me hanging from it). Started the engine fine afterwards as well.

Riccy.

PS - current battery measures 198 high, 118 wide and 230 long if that helps

Ok, it has a 6,6hp motor? Thats 4923,6 watts, and 410 amps... there is no getting away from that !
According to the workshop manual a stock battery is 36 AH/5hr.
It also states "Battery, common causes of failure, Electrical load exceeding generator output, particularly with addition of aftermarket equipment" So thats a limit of 70 amps, and you have to take into account how many amps the vehicle is already using to run !
A £85 bosch battery of 45ah is still only 330 cca. You must have a much bigger battery if yours has 440 cca?
Now to your load/current chart... all ratings are with just one layer on the drum... will you be winching with nearly all the rope payed out? Probably not, and with just 4 layers you have already halved the maximum amount of pulling force available, so what has that done to the current draw of the winch? now its getting much more complicated !
And dont forget, the 650 cca is the "minimum" for the winch....

No need to confuse him anymore than needed. I think most people will agree that theoretical numbers is one thing real life and practical use is another.

Fom what I can read, it sounds to me that Riccy is well aware if his battery's limitations.
No matter what, you don't need a dual battery setup to make decent power to a winch. Just one good battery to get the best out of it.

So instead of overthinking this.. just have a go with the winch