Be wary of, or careful when using, these dumb adapters. Lithium batteries require protection electronics, in particular ones to shut off the tool when the battery reaches too high a temperature or the cells reach too low a voltage. Most manufacturers put the electronics in the tool, using the connector's other conductors to sense the battery's condition. Since these cheap adapters don't also adapt the sensing electronics and conductors, the electronic safety is substantially or completely disabled. If the battery's user doesn't take as much care as the tool's electronics would have, there is a great increase in the probability of premature, and possibly incindiary, battery failure.