SHARP:
BT-L221 , BT-L221U , BT-L241 , BT-L441 ,
Do not short-circuit the sharp battery.Accidental short-circuiting can occur when a metaillic object such as a coin,clip,or pen causes direct connection of the positive(+) and negative(-) terminals of the bt-l221 battery.(These look like metal strips on the sharp bt-l221).This might happen,for example,wehn you carry a spare camcorder battery in your pocket or purse.Short-circuiting the terminals may damage the battery or the connecing object.
Keep the sharp bt-l221 battery contacts clean: Clean your battery's metal contacts every couple of months with a cloth moistened with rubbing alcohol. This keeps the transfer of power from your BTL221 battery pack more efficient.
If a replacement bt-l221 battery is being used for the first time or if the sharp bt-l221 battery has not been used for a prolonged period.it may be necessary to connect the sharp bt-l221 battery charger and then disconnect and reconnect it to start the charging.