Rechargeable Battery Service
PRIMECELL Division ~ CUNARD ASSOCIATES Inc. ~ Proud to be American
What do the technical terms mean ?
Some over simplified but helpful answers are ....
NiCd = Nickel Cadmium rechargeable battery. Single cell = 1.2V empty, 1.44 V full. V= Volts
NiMh = Nickel Metal Hydride rechargeable battery. Single cell = 1.2V empty, 1.45 V full. See frequent questions page about charging NiMh.
Li-Ion = Lithium Ion rechargeable battery. Single cell = 3.6V empty, 4.1 Volts full Li-Ion batteries require a special charging system. Other types of batteries may not be substituted. If your electronic appliance operates from LiIon batteries - it must be replaced with LiIon, Also refer to questions about rebuilding of Li-Ion batteries.
Lithium Polymer rechargeable battery. Single cell = 3.6V Similar to Li-Ion although made flexible or formed in thin sheets to conform to small compartments. These batteries require a special charging system. Other types of batteries cannot be substituted. Also refer to questions about rebuilding of Li-Ion batteries.
SLA = Sealed Lead Acid type rechargeable battery. SLA batteries can be in many different voltages and capacities. Basically they are constructed with 2 volt cells placed in series for higher voltages. Example: a 6 cell SLA battery is referred to as a 12 Volt SLA. In reality a 12 V SLA may be as high as 15 V when full, and as low as 10 Volts when empty. Sealed lead Acid batteries are not rebuildable. They must be replaced.
NDV = Negative Delta Voltage. Full charge detection. When NiCds are quick charged they increase in voltage to approximately 1.55 volts per cell then they start to decrease - this point at which they start to decrease in voltage is referred to as NDV.
PVD = Peak Voltage Detection. Full charge detection. When NiMh cells are quick charged they increase in voltage and peak at a point approximately 1.55 per cell. (No decrease). The point at which they peak and then start to decrease in voltage is referred to as PVD. PVD is the detection method for quick charging NiMh
TCO = Temperature Cut Off. A device used to monitor the temperature of the battery cells. If the value of the TCO (Thermostat) is exceeded, it acts as a switch to "cut off" the charge current, until the temperature is within accepted values.
"Delta T" Full charge detection by using battery cell temperature as a measurement. When NiCd and NiMh cells are quick charged, they increase in temperature in the last 10 % of full capacity. This temperature change can be used to end a charge cycle. It is referred to a "Delta T" The temperature is often measured by the resistance change to a Thermistor that is mounted inside in the battery pack. A safe guard used with "DT" is a measurement of time to fill the battery at the charge rate in use. If the Delta Temperature has not occurred, but the duration of charge time indicates a full capacity - the charge cycle is ended. This is known as Delta Time. If both are used it is called Delta Temperature / Delta Time.
C/10 = Capacity divided by 10 ("C over 10"). If a NiCd or NiMh battery is rated at 600mAh capacity, it may be charged at 60mA current for approximately 16 hours to achieve full capacity. This is referred to as charging at the C over 10 rate. Also referred to as the over night charge rate.
MAh = Milliamp Hours, Used to rate the capacity of rechargeable batteries. A 1000mAh battery can theoretically provide 1000mA for 1 hour. (It is not exactly that simple). It is a term used as relative grading for the amount of energy a cell can retain when fully charged. A similar term is AHr Amp Hours, which is used to grade larger capacities - it is the discharge rate stated as Amps ( equal to 1000 Milliamps)