Thanks Guys,

Getting my head around this now it's a bit clearer.

I'm wondering if this was ever working correctly as I'm sure the LM317 used is in constant voltage mode. That would explain why I am getting such a small change from the adc count?

Counts are typically 985 on one side, 961 on the other, giving me a count difference of 24 representing the voltage drop. The charger at the moment has a 1amp max output which I will be changing later to 5 amp using a LM338. Going from 300mA trickle to 1000mA charge at the moment only changes the count difference to 22, a change of 2 which doesn't seem right.

I'm on a different computer to the one I program on, so I will load the code and schematic for all to see. The original link to this project is now dead, it had all the details plus the hex code.

My coding style may not suit all but it usually gets the job done for me.

Rob