neb:

kryptonjohn:

 

I have a cheap Black&Decker Matrix 18V Li drill. Be interested to know what the charger smarts is,

 

If you can post photos of the charger circuitry, there are enough geeks on here to tell you whether it's got a decent charge controller or not.

The matrix ones I have just terminate the charge, they do not re charge at a later stage if the battery is sitting in them and seem to deplete them slowly if left in the charger and unplugged.