Thread: SPARE BATTERY (Ne auto sparkys out there)

Originally Posted by Trout

When out hunting I'm a few ks from any help if I have a problem with a flat battery or the alternator stops charging.Its happens twice over the yrs.So I carry a spare battery 750cranks even tho the 4.2tdi has 2 battery's,12v parallel.Battery weighs 22kgs.
Is there a smaller battery with not so many cranks,but capable of helping turning the engine over a few times if needed.Engine normally starts on 1st turn of the key,has been for the last 19 yrs iv own it.Only needs one battery to be flat and engine will not turn.I put 2 new batterys 4 yrs ago,generally they last about 7yrs.But you never know when something goes wrong.
Any info appreciated,thanks.

I hear what you are saying there, but it gets to a point where you go down on diminishing returns. You should be able if your batteries are good and the system is up to par crank the engine with only one battery connected on the short of the wiring harness with the 12v dual battery setups. I have done this a couple of times (the literal twice) although most of my time is with the 24v series connected import versions of this vehicle.

I would get one of the li-ion jump packs - as noted they do fine at what they need to do and do dual use as a emergency power source for cell phones etc as well as being a lot more resistant to being tipped over and spilled etc etc. They don't like being squashed though. I used to cart a lead acid battery in a box, strapped in with Andersen plug jumper leads set up with an isolating switch on it but the portable jump packs are just better now. I used to leave it connected to one side of the 24v setup for about 20mins, then swap it to the other and start as normal and the jump packs will do this just as well.

My experience of the TD42 setups both 12v and 24v, is the starting system is just as prone to issues as the charging side (which is to say they are both pretty bloody reliable and as you've noted the bits connected to them in the batteries are the weaker point in the system). If you have gotten to the point where you are starting to look for hills to park on to roll-start the vehicle you've got bigger issues than battery reliability haha.