my way of testing all of my laptop pull batterys,
there are two mods in this setup,
one mod is to charge the battery and the other mod is to disscharge under load (xml LED)
charger mod allows me to choose the way i want to charge my batterys, its adjustable constant voltage/current stepdown module up to 5A, so most power supply would do.
the disscharge mod is just an easy way for measuring the voltage of the battery under load, my way is to take volt reading after one min load, then i get an idea about the battery condition.
update:
the first two batterys i try to charge was already mostly charged, but then i try to charge a 3.5V battery and got wrong reading from the ammeter.
apparently, it was wrong to connect the power source of the ammeter with the same (parallel) power source of the charger, need an independent power to the ammeter.
this is how to do it properly:
