|Forum topic by David||posted 06-02-2011 05:05 PM||897 views||0 times favorited||2 replies|
06-02-2011 05:05 PM
In response to http://lumberjocks.com/topics/27462 , I was blocked so I figured I’d just start a new forum topic…
NiCd battery chargers like the ones Dewalt uses charge with a constant current, and detect end of charge by watching the cell voltage and stopping the charge when it droops slightly (-dV). This is why they can charge a range of pack voltages with one charger and do it fairly quickly. Connecting directly to a car battery will not offer this protection. The reason I haven’t done this is because I know it can damage the battery.
I don’t know exactly how they charge lithium packs with the same charger, but I’m guessing the charger can detect if it’s a lithium pack and adjusts the charge profile accordingly. Anyone know what chemistry Dewalt uses in their lithium packs?
The drill will run just fine, motors are pretty tolerant of differing voltages.
-- Perilous to all of us are the devices of an art deeper than we ourselves possess. --Gandalf the Grey http://davidwahl.org/category/woodworking/