A 510 battery that won't fire a connected cartridge has three usual causes: insufficient charge, dirty or oxidized 510 contact, or a faulty cartridge. First, charge the battery fully (most use USB-C or threaded USB chargers). If charged but still not firing, unscrew the cartridge, wipe the 510 thread contact on both the cartridge and the battery with a cotton swab and a drop of iso, and reconnect — buildup at the contact prevents electrical flow. If still not firing, test the battery with a different known-working cartridge to isolate whether the issue is the battery or the cart. Loose 510 cartridges that are screwed in too tight can also depress the spring contact past its travel range; back the cart off a half turn. The /collections/cartridge-510-thread-batteries selection at Angies Boutique stocks replacement batteries across all major form factors, and the staff at 838 N Broadway will diagnose a non-firing setup in person.