Twin Battery Question

[Nick V]

I know that my batteries are not the best and will have to replace them before the winter, but noticed something the other day when I had to jump start the truck.

I hadn't used the motor for a week or so and after I changed the fuel filter and had to turn her over a few times, it never had the balls to fire the engine so I had to jump start.

When I connected the jump leads to the battery on the o/s the engine did not turn over any quicker than before, but as soon as I connected to the n/s battery the engine turned over very quickly and fired immediately!!

Does this mean that the o/s one is knackered and the n/s one is doing all the work, or have I missed something and I should only be using the n/s for jump starting?

Cheers, Nick

[nero279]

either battery should be fine for jumpstarting, and it shouldn't make any difference which battery you connect the leads to, there's a nice fat bit of cable connecting bnoth positive terminals anyway, so if the battery you connect to doesn't want to take any power it should go to the other battery anyway.

It could be a loose or dirty terminal on the first battery, or just a poor connection between the terminal and jump lead. The only difference could stem from resistance because of the longer cable run from o/s battery to starter motor compared to n/s battery to starter motor (i think).

[Nick V]

Mmmmm, it don't make sense to me neither, but that's how it was and ll terminals/leads are ok!!! Back to the drawing board!!

Cheers, Nick

[NiftyNev]

Always jump start from battery nearest starter. Less voltage loss this way although it should still start from the other battery. If all the terminals are clean and making good contact the check the earth points on the o/s battery cables.

Nev