It is so simple,
@TartApple:
Volt (V) = unit of the driving force of the electric current (voltage). Example: 36 or 48 V battery.
Ampere (A) = unit of the electric current, or how much of current flows through the wire (continuously).
Ampere-hour (Ah) = unit of electric charge in the battery. If you have a 16 Ah battery and draw the current of 1 ampere, the battery will discharge after 16 hours.
Watt (W) = unit of power, or the energy spent in a time unit. W = J/s, where Joule is the energy unit. If your motor produces 250 Watts it means it is spending the energy of 250
Joules per second. 1 W is also equal to 1 V * 1 A. So, if your motor produces 250 Watts and the voltage is 36 V, the current flowing from the battery will be 250 / 36 = 6.94 A.
(
750 W is around 1 HP) An average cyclist can produce around 100 W with his or her legs. A professional cyclist can produce 300+ Watts with the muscle power.
Watt-hour (Wh) is the unit of energy stored in the battery. It is exactly equal to 3600 Joules. The battery capacity (amount of the energy stored there) is Volt times Ampere-hour. If your battery is 36 V and the battery charge is 16 Ah, then the battery capacity is 36 * 16 = 576 Wh. The same expressed in Joules is 576 Wh * 3600 = 2,073,600 Joules or 2,073.6 kilojoules (kJ).
Wh is a practical measure of the battery capacity.
Recharge cycles = how many times the battery was charged from minimum safe capacity (e.g. 5%) to 100%.
For the chemistry, please refer to:
en.wikipedia.org
Hope it helps.