5. Safety Notes for Lithium-Polymer Batteries
Important Product Information
Lithium-polymer batteries are the new generation batteries for RC sport. The energy density is three times higher than that of
Ni-Cd batteries. These new cells are capable of supplying relatively high power in relation to the cell‘s capacity.
Capacity and current:
The given capacity is the capacity guaranteed by the manufacturer at 1C discharge.
Thus a 1200 mAh cell can supply about 1.2 A for about 1 hour. The cell‘s current load is often given as a multiple of the capacity.
Cell
type
Capacity
2C 3C 4C 5C 6C
700 mAh 0,70Ah
1,4A
2,1A
2,8A
3,5A
4,2A
1200 mAh 1,2 Ah
2,4A
3,6A
4,8A
6,0A
7,2A
While many LiPoly cells reach their capacity between 2C and 3C continuous current discharge, the E-Tec and TP-cells can be
discharged at about 4C. However the life and the effi
ciency of the cell depends a lot on the discharge. Many fl ights and extensive
tests have resulted in the following recommendation:
Up to 5C – For maximum capacity and long life
6C – A possible compromise between high discharge currents and durability
7C – possible for short-term use if very high currents are needed.
Whenever possible systematic „easing off the throttle“ should reduce the average current load on the cell.
If you want to convert an existing drive to LiPoly cells you should take particular care to adjust it properly. If necessary the prop,
drive or even the number of cells should be changed.
LiPoly cells can be arranged in series (increased voltage) and parallel (increased capacity so the max.current load is also achie-
ved).
Charging:
Lithium-polymer cells have to be charged in a special manner. Only chargers specifi cally built to do this may be used. When
using chargers which adjust the number of cells and charging current automatically, care must be taken to ensure that incorrect
settings do not overcharge and destroy the cells.
Read the battery‘s and the charger manufacturer‘s instructions carefully before using the batteries as incorrect handling can
cause overheating, fi re, explosion, damage or loss of capacity of the battery. If you do not understand some of the instructions,
contact the dealer where you bought the battery and ask him to explain how to handle it.
These batteries are only intended for use in model making/model sport under normal conditions of use. The manufacturer is not
liable if the battery is used for any purpose other than that described here.
Warning! General Warning
Incorrect handling as described below or in any other way can lead to acid leakage, overheating, fi re and/or explosion!
Only use the battery under the following conditions:
Temperature
range:
Current: Voltage
:
Charging: 0 to +45 degrees C
Charging: Max. 1 CmA
Charging: 4.2 V +/- 0.05 V
Discharging: -20 to +60 degrees C
Discharging: maximum 2 CmA
Storage: 0 to +35 degrees C
Charging
:
Constant current - constant voltage
The battery has been charged slightly by the manufacturer. Charge the battery before fi rst use in accordance with the instruc-
tions.
Even if the battery is rechargeable it has a limited life. Should the battery‘s capacity be reduced after many times of charging
and discharging, dispose of it in compliance with local regulations. To do this, cover the plus and minus poles of the battery with
insulating tape and put the secured battery into a plastic bag which can be sealed. Never throw the battery into the household
waste.
