Li+ Battery 36V 20Ah, = 720 Wh , range 50 – 90 KM,
Lithium polymer packs refer to the way the pack is structured, using as a flat pack with multiple layers of the electrodes stacked with insulating film in between and covered in plastic foil. Cylindrical cells have a continuous foil of electrodes coiled and packed into a very thin steel casing.
18650 cells generally are rated at 3.6V and 2.2 Ah, so a pack with cells arranged 10 in series 3.6v x 10 = 36v and 5 of these in parallel would be 2.2 Ah x 5 = 11 Ah with some losses due to impedance in a series, the true capacity of a pack would be slightly lower. Each manufacturer of such cells have their own secrets to the chemical compositions and know-how, that’s where the differences lie.
The capacity of the battery is rated in Watts hours (Wh) which is the nominal voltage multiplied by the Amp hour (V x Ah).
(e.g. 36V x 10Ah = 360Wh). It is therefore essential to know both the V and Ah rating of a battery pack or the Wh directly.
Lithium batteries packs have a battery management system ( BMS ). It is an attached circuit board that performs the function of balancing the cells, short circuit protection, low voltage protection, over charging , limiting the maximum discharge current and temperature control.