45
b) Additional information about lithium rechargeable batteries
Modern lithium rechargeable batteries have a significantly higher capacity than NiMH and NiCd bat
-
teries and are also significantly more lightweight. This makes lithium batteries (especially Lithium
Polymer batteries) particularly suitable for use in model making.
However, LiPo batteries require particular care during charge/discharge, operation and handling.
The following sections provide an overview of the potential hazards associated with LiPo batteries
and explain how these hazards can be avoided to ensure a long lifespan for such batteries.
• The casing of many lithium batteries is made of one single thick film, which is very sensitive. Do not
dismantle, drop or insert any objects into lithium batteries. Do not apply mechanical loads or pull on the
battery’s connection cables. This may cause a fire or explosion!
Always observe these instructions when inserting or removing a battery from your model.
•
Ensure that the battery does not overheat during use, recharging, discharging, transport or storage. Do
not place rechargeable batteries next to sources of heat (e.g. a speed controller or motor) or expose
them to direct sunlight. This may cause the battery to overheat, which can cause a fire or explosion!
The temperature of the battery must not 60 °C. (If necessary follow additional manufacturer
specifications for the battery!).
•
If there are any signs of damage or the outer casing starts to swell or expand, discontinue use immedi-
ately. Do not charge it any more. This may cause a fire or explosion!
Exercise caution when handling the damaged battery and use suitable protective gloves. Dispose of the
battery in an environmentally friendly manner.
Never store such batteries in an apartment or in a house/garage. Damaged or swollen lithium batteries
may suddenly catch fire.
•
Always use a compatible charger to charge lithium batteries and/or always use the suitable charging
method. Do not use NiCd, NiMH or lead-acid battery chargers, as these may cause a fire or explosion!
Always select the correct charging method for your rechargeable battery.
•
Always use a balancer (already integrated into the charger, which is included in delivery content) when
charging a lithium battery with more than one cell.
•
The charge rate for LiPo batteries must not exceed 1 C (or the value stated in the battery instructions).
This means that the charging current must not exceed the battery capacity (e.g. battery capacity =
1000 mAh, max. charging current = 1000 mA = 1 A).
•
The discharge current must not exceed the value stated on the battery.
For example, if “20 C” is printed on the LiPo battery, the maximum discharge current is 20 times the bat-
tery’s capacity (e.g. battery capacity = 1000 mAh, max. discharge current = 20 C = 20x 1000 mA = 20 A).
Exceeding the maximum current may cause the battery to overheat or become deformed, which can
lead to a fire or explosion!
However, the printed value (e.g. 20 C) generally does not indicate the continuous current but the maxi-
mum current that the battery can deliver for a short period. The continuous current should not be higher
than one half of the stated value.
•
Do not allow the individual cells of a lithium battery to become fully discharged. Overdischarging of a
lithium battery may destroy the battery or cause permanent damage.
If the model does not have overdischarge protection or a low battery indicator, stop using it before the
battery becomes empty.
