Well, the key is whether they move. Small voltage batteries are safe to use for several seconds. By this I mean your typical AA to 9V fire alarm battery. Even on the tweeter.
Using a 9V battery for the woofer at least, they should move in or out, depending on how the battery is placed. + to + produces motion towards the listener. Make sure the crossover is 100% removed from the driver before testing or you’ll be testing the crossover as well.
Honestly it’s a shame more people don’t have Dayton DATS. It’s the best speaker circuit troubleshooter I know.