There’s a lot of misleading information on LiPo batteries but it does pay to be cautious.
From new a LiPo battery has a very low internal resistance, which allows it to supply a high level of current but over time Lithium Oxide builds up on the (internal) battery terminals. This build up increases the internal resistance and that creates heat when charging and discharging. At the same time the Lithium Oxide releases Oxygen, which can cause swelling of the battery pack.
During manufacture the batteries are squeezed to eliminate as much air as possible while at the same time increasing battery efficiency. A poor battery often means a poor seal and air still in the casing.
Something important to note: DO NOT store LiPo batteries in a sealed container - oxygen being released is the oxidiser that will feed a fire of a faulty battery.
LiPo batteries should not be stored fully charged. At their full individual cell voltage of 4.2V the batteries degrade. The internal resistance of the battery is the cause of the battery ‘losing’ power over time while at the same time creating even more Lithium Oxide. That is the reason the batteries automatically discharge after a selectable number of days.
LiPo batteries should never be fully discharged, once each cell drops to 3.2V they rarely recover.
DJI’s ‘Intelligent’ batteries monitor each individual cell, ensures each charges to the correct voltage, monitors temperature and discharge rate and logs this data to the flight’s .txt file. Note also that the discharge rate is monitored. If an individual cell’s discharge rate is lower than the others then the other cells are discharging at a higher rate, will increase in temperature and can potentially exceed the cell’s designed discharge rate.
Beware of using non-LiPo battery chargers - they don’t provide the required charging needs of LiPo batteries. Likewise don’t use a fast charger - they reduce the battery lifespan and create additional heat while charging.
Each battery has a design life of approximately 150–250 cycles if maintained correctly.
For safe storage use a fireproof bag or metal box but not sealed.
Never leave a charging LiPo battery unattended, i.e, don’t leave the house empty with a battery charging.
LiPo batteries are very safe if used correctly and handled and stored safely. Remember LiPo batteries can, and must, be carried in the cabin on an aircraft. If they weren’t safe they would have been banned long ago.
If you have a swelling battery within warranty and under 250-cycles, DO NOT charge it - return it to DJI.
