proper voltage divider for battery voltage detection

Did you read the article from the link in post#3. Leo..

Wawa: Did you read the article from the link in poast#3. Leo..

yes, that's where I got circuit #1 in the OP :)

I'm just wondering if the R3 in the other circuits do anything.

arusr: Hello,

Maybe mentioned in this thread somewhere already. An virtually unloaded battery often reads higher than expected voltage (compared to when it's working - putting out an adequate amount of current).

Maybe you could use a fet switch or something ... to switch in a divider circuit or whatever - just for the duration of time that you want to take measurements.