Graupner Hendheld RC 2.4 GHz No. of channels: 12 33124 Data Sheet

14

 Transmitter power  supply
The 

mx-20 HoTT transmitter has a highly capacitive, 

rechargeable NiMH battery, 4NH-2000 RX RTU (Order 
no. 2498.4FBEC), as standard equipment. (changes 
reserved) However, the standard built-in battery is 
not charged upon delivery of the transmitter. 
When the transmitter is used, its battery voltage 
should be monitored by way of the indicators provided 
in the LCD display. If battery voltage drops below 
the adjustable voltage setting (set via item "Batterie 
warning" in the "Basic Settings" menu, page 226,), 
default value 4.7 V, an audible warning signal will sound 
and the message window shown below will appear in 
the screen 

GRAUBELE

#01

0:22h

Stop
Flug

0:00
0:00

0.0V

10%

4.6V

M

x

x

HoTT

batter y

needs
charging

No later than now, operation must be terminated so the 
battery can be charged again. 

The transmitter's rechargeable NiMH battery can be 
recharged by connecting the charging jack located, 
on the right side of the transmitter, with the included 
charger (order no. 33116.2).
As a rule of thumb for charging time, an completely 

discharged battery will require 12 hours to recharge at a 
current rate equal to one tenth of its specifi ed capacity. 
For the standard transmitter battery and included 
charger, this is a current rate of 200 mA. However, 
you must yourself ensure that the charging process is 
terminated when it should be …
The transmitter must be switched "OFF" during 
the entire charging procedure. Never switch on the 
transmitter when it is connected to the charger. Even 
a brief interruption to charging can cause charging 
voltage to rise to a level that will immediately damage 
the transmitter with over-voltage. Also for this reason, be 
sure all connectors are always plugged in securely and 
have good contact. 

mx-20 HoTT charging jack polarity
The charger cables on the market from other 
manufacturers often have different polarities. Therefore use 
only an original Graupner charger cable, order no. 3022.

 

Charging with automatic chargers
The transmitter's charger jack does come standard 
with reverse polarity protection but nevertheless it can 
be used with suitable chargers for quick charging the 
transmitter's battery.
Set the quick charger unit, according to its manual, for 
a delta peak voltage difference of 5 mV … 20 mV or 
equivalent such that it is adapted for quick charging 
NiMH cells 
First connect the charger cable's banana plugs to 
the charger and only then connect the cable's other 
end into the charging jack on the transmitter. Never 
allow the bare ends of the banana plugs to come 

into contact with one another when the other end of 
the cable is plugged into the transmitter. In order to 
prevent damage to the transmitter, charging current 
should never exceed 1 A. If necessary, limit the 
current at the charger.

To remove the transmitter's battery, fi rst unlatch the 
cover of the battery compartment on the rear side of the 
transmitter housing then remove the cover.

Take out the transmitter's battery then disconnect the 
transmitter battery's connector by carefully pulling on the 
supply line cable. 

Hold the transmitter battery connector 
such that the black or brown cable is 
oriented toward the antenna side and 
the empty jack of the battery connector 
is oriented toward the fl oor side then push the battery 
connector in the direction of the board onto the three pins 
sticking out out of the board inside the transmitter. (The 
battery connector is protected against a reverse polarity 
connection by two slanted edges, see illustration.) 
Place the battery into its compartment and close the 
cover.

Transmitter 
connector polarity