Overcharging or leaving the battery on the charger after reaching a full charge is not recommended for several reasons, the most serious being it may result in fire. Always put the battery inside a fire resistant battery bag or container to charge.
It should not be possible to overcharge the battery if you are using the charger properly. Leaving the battery plugged into the charger may risk overcharging one or more cells inside the battery causing it to become swollen or otherwise misshaped.
If your battery appears misshaped, swollen, or puffy, - do not attempt to charge or use it. Keep it away from anything flammable and responsibly dispose of the battery as soon as possible. A swollen battery can become dangerous.
If left on the charger after the battery has reached a full charge may permanently damage the battery. Here's why:
The last part of the charge cycle is the balancing stage. During this part of the cycle, the charger is balancing the voltage charge across all three, or four cells* of the battery pack. This may result in the charger "leaving a cell behind" in the charge/balance process - resulting in NOT getting all three green lights if using the B3Pro charger or NOT seeing FUL if using the HotRC charger. And may also permanently damage your battery. It may stop charging, holding a charge, or even cause it to swelling.
If your battery is swollen or misshaped - keep it away from anything flammable until you can responsibly recycle it. Don’t just put your batteries in the regular trash! Google "battery recycle center near me" for a place that you can drop your old and damaged batteries off for recycling.
* The 11.1v Home Original battery is a three cell battery; the 14.8v Home Plus battery is a four cell battery.
CAUTION: The battery should always be allowed to come to room-temperature before charging. Charging a hot or cold battery might delay charging or damage the battery. For best results, charge the battery at temperatures between 50º and 80ºF (10º-30ºC).
The advice given above is general in nature and you are responsible for the safety of your batteries. SwiftPaws is not responsible for any direct, indirect, special, or consequential damages and personal injuries, including that to life, and health, resulting from the customer’s application and use of batteries sold by SwiftPaws.com.