If the charger pops, smokes, or there is a bad odor this is an indication of a bad charger. Discontinue use and replace the charger.
The HotRC charger has a fire resistant case. During a certain phase in the charging cycle it gets very hot - this is normal. But if the charger becomes too hot to hold, unplug it and do not attempt to use it. Replace the charger.
You should always use the charger on a fireproof surface, away from anything flammable. You should not leave the charger unattended when in use. If you need to leave, stop charging and continue the recharge once you're able to be present.
Contact support@swiftpaws.com if your unit is under warranty for a replacement, or purchase a new one on our website here: https://swiftpaws.com/products/upgraded-charger-for-home-or-home-plus (or a compatible one anywhere they're sold)
Always charge the LiPo batter inside a fireproof container such as a fireproof charging bag.