Our V3i batteries have a number of safety cutoffs built into them so that they won't fire in unsafe situations, but there are things to be aware of when using or charging your V3i batteries.
Firstly, don't use a battery that's damaged in any way, whether this is to the body of the battery or the connection.
Don't use a charger that is visibly damaged, whether this is to the cabling or either socket.
If using a wall adaptor, make sure that this is 1.5amps or lower, and not a 'fast-charge' adaptor which often comes with mobile phones. You can find our recommended wall adaptor here.
Don't leave the battery charging for extended periods of time (such as overnight) or leave it unattended while charging, and be sure to charge it on an inflammable surface.