Dewalt 20V max battery won't charge after dropping it - any ideas?

So I dropped my Dewalt 20V max battery (6Ah) from about 4 feet onto concrete. Now when I put it on the charger, the charger just blinks red rapidly and won't charge. Battery looks fine externally, no cracks. Any way to fix this or is it toast?

That rapid red blink usually means a dead cell or internal damage. First, try cleaning the contacts with a little alcohol. If that doesn't work, you might have to crack it open and check the cells. I've revived a few by replacing individual 18650 cells, but you need a spot welder and know what you're doing. Otherwise, just recycle it and buy a new one - batteries are cheaper than a fire.

⚠️ Safety first! If the battery is damaged internally, it could short or catch fire. I'd say don't try to fix it unless you're experienced with li-ion batteries. The BMS (battery management system) might have detected a fault and locked it out. My advice: recycle it properly and get a replacement. Not worth risking your shop.

I've had luck with a 'nudge' trick - sometimes the cells just get misaligned. Try tapping the battery gently on its side a few times, then put it on the charger. If that doesn't work, check voltage with a multimeter. If any cell is below 1V, it's done. But yeah, dropping is bad news for these packs. The Dewalt 6Ah are pricey, so I feel your pain.

Thanks everyone. Tried cleaning contacts - no change. Tapping didn't work either. I think it's dead. Guess I'm ordering a new one. At least it's a good excuse to upgrade to the PowerStack? Thanks for the help!