Basic knowledge about lithium polymer batteries
What is lithium polymer battery?
1 lithium polymer batteries, (commonly short for LiPo, LIP, Li-poly ), is a rechargeable lithium-ion battery. lithium polymer batteri apply a polymer electrolyte instead of liquid electrolyte, which makes it less powerful when there is leak or explosion. LiPo cells are now widely used in drone, mobile phones MP4 and other portable electronics.
How to select from lithium polymer battery and lithium ion battery?
As far as end user is concerned, lithium polymer battery(LIP) is essentially much better then lithium-ion battery (LIB). LIP has higher energy density then LIB, what’s more LIP is much safer then LIB, LIB can easily make explosion when short cut or over charged etc, while LIP has no such problem, LIP will simply Expand and blow and no explosion for most of the time.For New devices like Bluetooth or some medical device that require unique design of shape, LIP can be of great value, there is curved batteries and super thin battery cells among LIP manufacturer.
What is a 3s 5s lithium polymer li po?
Battery pack that contain 3 or 5 cells connected in series, they are called 3s or 5s LiPo batteries. A 3S lithium polymer battery 11.1 v(12V), and a 5S battery rated voltage 18.5 volts. but we know a single cell capacity is limited, so people will use more cell to parallel and get more capacity(also call Ah or mah). So 3s2p is 6 cell in total, suppose each cell 3.7v 2500mah a 3s2p pack is 11.1v 5000mah in total. Depending on different applications. Some lithium polymer batteries required an extra PCBA(lithium polymer bms). while some without PCB, just leave balance wire for lithium polymer battery pack.
What does the 10C means for lithium polymer cells? What is C rate anyway?
People use C Rate to define a discharge rate. Most lithium polymer battery specifications description something like “10C to 20C”. This means that 10C is the nominal discharge rate and 20C is the maximum discharge rate.It’s common to use mah to define battery storage capacity. A battery with a 2000 mAh capacity can deliver 2 Ampere ( usually short for 2000 mA/2A, 2A=2000 ma) for 1 hour. to make it more clear, it can also send power in 200 mA for 10 hours. The battery capacity, together with the LiPo battery’s discharge rate will define its maximum current output (Ampere, A).A 3S 2000 maH 10C LiPo pack will get you this: 2000 mAh x 10C = 20.000 mAh discharge rate 20.000 mAh / 1000 = 20 A constant discharge rate.So if your projects requires constant discharging rate higher then 20A, you will need to choose another battery pack, always check with the motor description or product description when you select the battery cells.