Good day !
Is it unobtanium ? Do you have one ? Looking to learn if other chargers can be used for a plain 20V XR lithium battery pack for tools. I believe there is a thermal contact which I do not know if tells the charger low or high for hot or for cold; and the ID contact, I suppose tells the charger the nominal voltage of the pack, besides balancing series-points and +/-

 

The Dewalt chargers do monitor temperatures, and shut off charging if the battery pack is too hot. This happens often if it is rapid charged over and over in the same day (within a few hours and after heavy use)
I use two different dewalt chargers for the 3Ah and 5Ah batteries. Seems to make no difference which charger is used for which battery, just that charging times may be different..
But, use the proper Dewalt chargers, don't try to jury-rig some other charger for those batteries.
Never seen a schematic for the chargers...

 

Thanks.
Am aware of precautions for charging.
The charger schematic is available on the web; what am after is the battery pack schematic.

 

Good day !
Is it unobtanium ? Do you have one ? Looking to learn if other chargers can be used for a plain 20V XR lithium battery pack for tools. I believe there is a thermal contact which I do not know if tells the charger low or high for hot or for cold; and the ID contact, I suppose tells the charger the nominal voltage of the pack, besides balancing series-points and +/-
View attachment 239955

I have some dewalt batteries that wouldn't charge on a regular charger. I also have the some of the old style '18v' lithium batteries and charger. Keep in mind, 18v and 20v max batteries are the same voltage. I used a battery adapter for new batteries on old tools, to charge 20vmax batteries on the old '18v' charger. It won't balance the batteries the same, but I can't even charge them on a 20v max charger. Also I've had a 20v max battery that was believed to be too low of voltage and wouldn't charge. After charging the battery on the old style charger with a battery adapter, it began taking a charge on new chargers again