Thread: Leaking Voltage?

I still have not found a fault, I did however rechecked the Aux Yellow Top and after a week being disconnected it has dropped to about 11.4 volts.
Could this battery be dragging the Main one down when linked?

Hi Rich, and if you do not have anything connected to the Yellow Top, it should not be self discharging. An Optima can hold their charge for up to 12 months.

It sounds like the Optima MIGHT be faulty but before you consider replacing it, if you have a battery charge, take the Optima out of the D3 and charge it.

By taking it out of the D3, nothing other than the battery charger is connected to it so you guaranty nothing else is discharging it.

Once it is charged, see if it holds it’s charge over the next week.

This does not resolve the problem of your cranking battery going flat unless the SC80-LR is also faulty and you can send it to me if you want it checked.

Ok I've had the Yellow Top out of the D3 and on charge for 24hrs.
1 hr after disconnecting it was a 12.2 volts, 2 hrs latter it's at 11.8 volts.
I'll see what the charge is at 12hrs & 24hrs!

So my first thing it looks like is to replace that battery, then see if my problems continue.
But why is my Main battery being dragged down with it?

Thanks for the input guys.

Originally Posted by ~Rich~

But why is my Main battery being dragged down with it?

Because the SC80 is keeping the 2 connected down to a low enough voltage to cause the main battery to get too low, perhaps by design or because its not quite right.

Hi Graeme and the SC80-LR is designed to cut-out at 12.0v so if it’s cutting out at a lower voltage there is a problem with the SC80-LR.

Rich, the other thing to try is disconnect the main cable running from the cranking battery to the SC80-LR. This is easily done by separating the Anderson Power Poles near the SC80-LR.

This will turn the SC80-LR completely off and then see if your cranking battery still goes flat.

Yellow top @ 12hrs = 11.5v
@ 24hrs = 11.4v

Hi Rich and thats a bit strange.

After the initial voltage drop, I would have expected it to drop to around 10.5v, indicating a dropped cell.

It may still have some surface charge, could you try putting a load on it for a few minutes and see if it drops to 10.5v.

Probably worth finding someone with another multimeter and comparing the two. 1/2 volt difference isn't uncommon with the cheap ones.