Is the behavior of cordless tools as their batteries run down different for nicad vs lithium batteries?
I notice that with a nicad battery in my cordless weed trimmer, the tool gradually slows down as the battery gets low. The same is true of the nicad batteries for my other cordless tools.
With lithium batteries in the weed trimmer, the tool just stops when the battery gets low. When I press the switch again it may run for a short burst and then stop again. When the lithium batteries for the cordless lawn mower get low, the machine just stops. (I haven't used lithum batteries in other cordless tools enough to notice their behavior.)