General Notes On Using The Charger - GRAUPNER ULTRAMAT 14 PLUS Operating Manual

3. General notes on using the charger

Charging batteries
When a battery is charged, a particular quantity of electrical energy is fed into it. The charge
quantity is calculated by multiplying charge current by charge time. The maximum permissible
charge current varies according to the battery type, and can be found in the information provided
by the battery manufacturer.
It is only permissible to charge batteries at rates higher than the standard (slow) current if they are
expressly stated to be rapid-charge capable. The STANDARD CHARGE CURRENT is 1/10 (one
tenth) of the cells' nominal capacity (e.g. for a 1.7 Ah pack the standard charge current is 170 mA).
• Connect the battery to be charged to the charger output sockets using a suitable charge lead (red
= positive terminal, black = negative terminal).
• Be sure to read the information provided by the battery manufacturer regarding charging methods,
and observe the recommended charge currents and charge times. Do not attempt to fast-charge
batteries unless they are expressly stated to be suitable for the high currents which this charger
delivers.
• Please bear in mind that new batteries do not reach their full capacity until they have undergone
several charge / discharge cycles. You should also be aware that the charger may terminate the
charge process prematurely when connected to new packs, and batteries which have been
deep-discharged.
• A Ni-Cd pack will normally be warm at the end of a rapid-charge process, but if you notice that one
cell of the pack is much hotter than the others, this may well indicate a fault in that cell. Such packs
could fail completely without warning, and should not be used again. Dispose of the battery safely,
preferably taking it to a toxic waste disposal centre.
• Ensure that all connectors and terminal clamps make good, sound contact. For example, if there
is a brief interruption due to an intermittent contact, the result is inevitably a malfunction such as
a restart of the charge process, which would result in the pack being massively overcharged.
• A common cause of malfunctions is the use of unsuitable charge leads. Since the charger is
incapable of detecting the difference between a pack's internal resistance, cable resistance and
connector transfer resistance, the first requirement if the charger is to work perfectly is that the
charge lead should be of adequate conductor cross-section and should be not be more than
30 cm long Good-quality connectors (gold-contact types) must be fitted to both ends.
• Charging transmitter batteries
A battery installed in a radio control transmitter can usually be recharged via the integral charge
socket which is fitted to the transmitter itself. Transmitter charge sockets generally include a
diode which prevents reverse current flow. This prevents damage to the transmitter electronics
should the charger be connected with reverse polarity, or if a short-circuit occurs between the
bare ends of the charge lead connectors. However, a transmitter battery protected in this way
can only be charged by the ULTRAMAT 16 if the diode is by-passed. Please read your transmitter
operating instructions for information on how to do this. The stated maximum charge current for
the transmitter battery must never be exceeded. To avoid possible damage to the internal
transmitter components due to overheating and heat build-up, we recommend that the battery
should be removed from the transmitter's battery compartment prior to charging. The transmitter
must be set to „OFF" and left in that state for the whole period of the charge process.
Never switch a radio control transmitter on when it is still connected to the battery charger. The
slightest interruption in the charge process may allow the charge voltage to rise to the point
where it immediately ruins the transmitter.
Never attempt to carry out any battery discharge or battery maintenance programs via the
transmitter's integral charge socket. The charge socket is not suitable for this purpose.
When you set a particular current for charging, the charger only supplies that current if the
value does not exceed the unit's technical capacity. If you set a charge current which the
Charger cannot deliver because it falls outside its technical limits, the unit automatically
reduces the current to the maximum possible value. In this case the screen displays the
charge current which is actually flowing, alternating with the warning message „MAX".
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