Adcin charger

I am using adcin to measure the voltage on my 12 v battery, when the battery gets to low i activate my battery charger with a small relay. Now the problem is as soon my charger start charging my battery the adcin now reads 12.6 v which it think my battery is full charge but it is not. I need to find away to isolate my battery and my charger voltages so even when the charger is on the adcin can read the true volts in my battery. Those anyone have a idea or as experienced this before.

Any advice would be appreciated.

Hi Mitch,

sorry for the question, but you need a PIC to charge a lead acid battery?
There are a lot of charging circuits out on the web.
Look at national.com for the datasheet of the LM317, there is also an application circuit as lead acid charger.

Back to your question...
when charged, the battery is full when the terminal voltage is around 14.4V, depending on temperature and charge method.
With 12.6V you will not get your battery fully charged.

Regards,
Ingo