Lithium polymer (LiPo) battery cells are increasingly popular and are used extensively in remote control models, particularly aeroplanes. LiPo cells produce 3.7 volts and have a capacity of 2,100 mAh (milliamp hours), if in good condition, which is approximately three times more than a nickel-based rechargeable battery. If you want to test the condition of your LiPo battery pack then use a multimeter and you can test the voltage and mAh.
Charge your LiPo battery pack in the usual way until fully charged. Remove the battery pack from the charger once charged.
Look on the label on the LiPo battery pack. You need to find out the output voltage and mAh rating. The voltage figure is always a multiple of 3.7 and the mAh always a multiple of 2,100. For example, a LiPo battery pack using three cells has a voltage of 11.1 and mAh of 6,300. The figures on the label are the figures you can expect to get when you test the battery using the multimeter.
Set the multimeter to read voltage. Check the two terminals on the battery pack to determine which is positive and which is negative. They are labelled "+" and "-" respectively.
Place the metal sensor attached to the end of the red wire that extends from the multimeter onto the positive LiPo battery terminal. Place the metal sensor attached to the end of the black wire extending from the multimeter onto the negative battery terminal.
Read the voltage output on the multimeter display. It reads the same as on the battery pack label. If the voltage is more than five per cent less then it's likely the battery is losing charge quickly as you have only just charged it.
Set the multimeter to measure mAh. Place the two sensors on the battery terminals as before. Read the mAh on the multimeter display. It is the same as the label on the LiPo battery. If the mAh is more than five per cent below the figure on the label it's likely you have a problem with your battery pack as it should not lose energy after just getting charged.
Leave the LiPo battery overnight. Do not use it as you need to see if it loses charge while not in use. A good battery pack has the same readings the next day.
Repeat the voltage and mAh test using the multimeter in the same way as before. The readings are identical, if the LiPo battery pack is in good condition. If either the voltage or the mAh readings have reduced by more than 5 per cent then you need to consider getting your LiPo pack refurbished or replaced as you will find it gradually gets worse.