User's Manual

9
Safety Notes
Charging
Ni-MH batteries should only be charged using the speci-
fi ed currents, charge times and temperature range, and
should be supervised constantly when on charge. If you
do not have access to a suitable fast charger, i. e. one
which allows you to set the charge current accurately,
then the battery should always be recharged using the
“normal” charge rate of 1/10C; see the example stated
above.
Wherever possible, transmitter batteries should
always be recharged at the 1/10C rate, in order to
avoid differences in cell states. The charge current
must never exceed the maximum permissible value
stated in the transmitter instructions.
Temperature charging
You can use this method if you have access to a suitable
battery charger with temperature cut-off system, fi tted
with a temperature sensor. However, the battery should
always be taken out of the device beforehand.
Cut-off temperature when charging at 1C: maximum 40
… 50°C.
Never charge to a higher temperature than 60°C, •
and ensure that the temperature sensor has good,
reliable contact with the battery. Check that the cor-
rect temperature is displayed, and that the charge
process is terminated at the correct point. For this
reason the temperature sensor should be as small as
possible; if in any doubt, set a cut-off temperature 10
… 15°C lower than stated above.
Note:
Charging to a temperature higher than 45°C causes
a slight reduction in the effective life of the cells.
Never start a new charge process if the battery is •
already or still warm.
Never leave batteries on charge unsupervised.•
Fast charging
The delta peak charge cut-off voltage should be set •
to 10 … 20 mV per cell. Most battery chargers are
set to a fi xed cut-off value of 15 … 20 mV per cell
by default, which makes them suitable for use with
NiCd and Ni-MH batteries. If you are not sure about
this, please refer to the operating instructions sup-
plied with your charger, or ask at your local model
shop whether your charger is also suitable for Ni-MH
packs. If in any doubt, charge your batteries at half
the stated maximum charge current.
It is always best to charge your batteries immediately •
before you plan to use them, as Ni-MH packs only
deliver their optimum performance directly after
charging, i. e. when still warm (40 to 50°C). These
batteries exhibit a high rate of self-discharge, and
quickly lose 10 … 30% of their capacity over just a
few hours. The internal resistance of Ni-MH cells also
rises enormously when they are cold.
Discharging
All rechargeable batteries sold by Graupner and GM-
Racing are suitable for a maximum continuous current
load of 6C … 13C, according to battery type (refer to the
manufacturer’s specifi cation!). The higher the continuous
current load, the shorter the batteries’ useful life.
Use your battery until its performance falls off, or until •
the low voltage warning is triggered.
Caution:
When stored for a long period, the cell voltage should
not be allowed to fall below 1.2 V. This means that
you may have to recharge the battery before stor-
ing it.
Refl ex charging and charge / discharge (cycle) •
programs shorten the effective life of batteries unnec-
essarily, and are only suitable for checking battery
quality or “reviving” relatively old cells. It also makes
no sense to charge / discharge a battery before using
it - unless you simply wish to check its quality.
Disposal of exhausted dry and rechargeable batter-
ies
The German Battery Order places a legal requirement
on every consumer to return all used and exhausted
dry cells and rechargeable batteries. It is prohibited to
dispose of these items in the ordinary domestic waste.
At no charge to the user, old dry and rechargeable
batteries can be surrendered at local authority collec-
tion points, Graupner retail outlets, and any other shop
where dry and rechargeable batteries of the same type
are sold. You can also send batteries supplied by us to
the following address - with adequate pre-paid postage
- for disposal:
Graupner GmbH & Co. KG
Service: Gebrauchte Batterien (Used batteries)
Henriettenstr. 94 - 96
D-73230 Kirchheim unter Teck
You can make an important contribution to environmen-
tal protection in this way.
Caution:
Damaged batteries may require special packaging be-
fore despatch, as some contain highly toxic materials!!!!!