COMMONLY USED TERMS
Commonly used terms
Final charge voltage: the voltage at which the battery's charge limit (capacity limit)
is reached. The charge process switches from a high current to a low maintenance
rate (trickle charge) at this point. From this point on further high current charging
would cause overheating and eventual terminal damage to the pack.
Final discharge voltage: the voltage at which the battery's discharge limit is
reached. The chemical composition of the batteries determines the level of this
voltage. Below this voltage the battery enters the deep discharge zone. Individual
cells within the pack may become reverse polarized in this condition, and this can
cause permanent damage.
A, mA: unit of measurement relating to charge or discharge current.1000 mA = 1 A
Ah, mAh: unit of measurement for the capacity of a battery (Amperes x time unit; h
= hour). If a pack is charged for one hour at a current of 2 A, it has been fed 2 Ah of
energy. It receives the same quantity of charge (2 Ah) if it is charged for 4 hours at
0.5 A, or 15 minutes (=1/4 h) at 8 A.
'C'-rating: Capacity is also referred to as the 'C' rating. Some battery suppliers
recommend charge and discharge currents based on the battery 'C' rating. A
battery's '1C' current is the same number as the battery's rated capacity number, but
noted in mA or amps. A 600mAh battery has a 1C current value of 600mA, and a 3C
current value of (3 x 600mA) 1800mA or 1.8A. The 1C current value for a 3200mAh
battery would be 3200mA (3.2A).
Nominal voltage(V): The nominal voltage of the battery pack can be determined as
-.NiCd or NiMH: multiply the total number of cells in the pack by 1.2. A 8-cell pack
will have a nominal voltage of 9.6 volts (8x1.2).
-.LiPo: multiply the total number of cells in the pack by 3.7. A 3-cell LiPo wired in
series will have a nominal voltage of 11.1 volts (3x3.7).
-.LiIo: multiply the total number of cells in the pack by 3.6. A 2-cell LiIo wired in series
will have a nominal voltage of 7.2 volts (2x3.6).
-.LiFe: multiply the total number of cells in the pack by 3.3. A 4-cell LiIo wired in
series will have a nominal voltage of 13.2 volts (4x3.3).
If the nominal voltage of the battery is not printed on the battery's label, consult your
battery manufacturer or supplier. Do not guess the rated voltage of battery.