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Lithium Batteries; Lithium Charge Program - GRAUPNER ULTRAMAT 10 Operating Manual

Low-cost all-purpose fast charger for ni-cd, ni-mh, li-io and li-po cells.
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As soon as the Delta Peak circuit terminates the charge process,
_ _ _ _ _ _ _ _
E N D
0 . 2 A
the Ultramat 10 emits an audible signal lasting about 10 seconds
_ _ _ _ _ _ _ _
1 3 . 7 3 V
(no audible signal if the buzzer is switched off). The screen dis-
plays the superimposed message „END" at regular intervals. The
bottom line of the screen displays the actual battery voltage.
The unit continues to charge the battery pack at a low trickle char-
INC
DEC
ge current until the battery is disconnected from it. The trickle char-
ge rate varies according to the battery pack connected to the char-
ger, and is calculated automatically. The top line of the screen dis-
plays the value of the trickle charge current.
_ _ _ _ _ _ _ _
5 0 m
2 6 s
You can display the charge time and the charged-in capacity by
_ _ _ _ _ _ _ _
3 4 5 2 m A h
pressing one of the INC / DEC buttons.
If a problem arises, perhaps with premature charge termination, it
is a good idea to check the setting of the safety timer (see page
11). Another possible cause for a premature termination may be
that the set value for Delta Peak sensitivity is incorrect.
_ _ _ _ _ _ _ _
E N D
0 . 2 A
If you suspect this, please check the information supplied by your
battery manufacturer.
_ _ _ _ _ _ _ _
1 3 . 7 3 V
When the charge process is complete you can safely disconnect
MODE
the battery from the charger. Press the MODE button to return to
the original charge menu. Please note that the charge time and the
charged-in capacity are not stored, and are erased when you
_ _ _ _ _ _ _ _
N i
5 . 0 A
press the MODE button.
_ _ _ _ _ _ _ _
1 5 m V / C

10. Lithium batteries

This charge program is only suitable for charging Lithium-Ion batteries with a nominal cell voltage
of 3.6 V and Lithium-Polymer batteries with a nominal cell voltage of 3.7 V.
The main outstanding feature of Lithium batteries is their much higher capacity compared to other
battery types. This is an important advantage, but it is balanced by the requirement to handle the
batteries differently, especially with respect to charging and discharging, if the danger of using
them is to be minimized. There are important basic rules governing the handling of these cells, and
they must be observed at all times. For additional information and safety notes please study the
battery manufacturer's published specifications. The fundamental rule is that Lithium-based
batteries may ONLY be charged using special chargers which are designed
and set for the actual battery type (final charge voltage, capacity).The method
of charging these batteries is different to the one employed with Ni-Cd or Ni-
MH batteries, and is based on a so-called constant current / constant voltage
process. The charge current required varies according to the battery
capacity, and is set automatically by the charger. Lithium batteries are
generally charged at 1 C (1 C charge current = capacity charge current. Example: with a battery
capacity of, say, 1500 mAh the corresponding 1 C charge rate is 1500 mA, or 1.5 A). For this
reason the value which has to be entered on the charger is the battery capacity, rather than the
charge current. Once the battery reaches the final charge voltage appropriate to the specific
battery type, the charger automatically reduces the charge current in order to prevent the final
charge voltage being exceeded. If the battery manufacturer states a charge current lower than 1
C, the capacity charge current must be reduced accordingly.
Problems with mis-handling of batteries:
Overcharging a Lithium-Ion battery involves a very great risk. Overcharging causes „gassing"
22
(gas generation), overheating and even to explosion of the cell. If the final charge voltage of 4.1 V/
cell (Lithium-Ion) or 4.2 V / cell (Lithium-Polymer) is exceeded by more than 1%, the lithium ions in
the cell start to change into metallic lithium. The lithium reacts very violently with water in the
electrolyte, and it is this which can lead to the cell exploding. On the other hand it is also important
that the final charge voltage should not be too low, otherwise the capacity of the Li-Ion battery cell
is significantly reduced. A value of just 0.1 V below the threshold equates to a capacity loss of
around 7%. Deep-discharging any lithium battery results in rapid capacity loss. This effect is
irreversible, so it is vitally important to avoid discharging the battery to a point below 2.5 V / cell.
Caution: the set cell type, cell capacity and cell count (number of cells) must always be correct
for the battery to be charged; there must never be any discrepancy - explosion hazard! If your
battery is fitted with an integral charge mechanism, it must not be connected to this charger.
Charge your Lithium batteries only on a non-flammable base surface.
INC
+
_ _ _ _ _ _ _ _
L i
( P o )
_ _ _ _ _ _ _ _
2 0 0 0 m A h
+
INC
DEC
INC
+
_ _ _ _ _ _ _ _
L i P o ( 3 C )
_ _ _ _ _ _ _ _
1 2 . 3 0 V o
ENTER
C H G
_ _ _ _ _ _ _ _
2 . 0 A
_ _ _ _ _ _ _ _
voltage
1 2 . 6 0 V
current
charge time
INC
DEC
_ _ _ _ _ _ _ _
8 m
_ _ _ _ _ _ _ _
2 3 2 m A h

Lithium charge program

Holding the ENTER button pressed in for about two seconds swit-
DEC
ches the charger from Ni-Cd / Ni-MH charge mode to the Lithium
-
charge program, and back again.
First you must select the Lithium type using the INC / DEC buttons,
while the type (in brackets) flashes in the top line of the screen.
-
For Lithium-Ion batteries select „Li (Io)", for Lithium-Polymer and
Manganese cells select „Li (Po)".
Press the ENTER button to confirm your choice; the bottom line of
the display will now start to flash.
The next step is to set the capacity of the cells you wish to charge.
You can set any value within the range 100 mAh to 9900 mAh in in-
DEC
crements of 100 mAh.
-
The charger automatically calculates a charge current of 1 C from
this.
At this point the Lithium battery pack can be connected to the char-
ger. The display now stops flashing.
Press the ENTER button to move to the Cell Count menu, where
you have to enter the number of cells to be charged.
The charger calculates the cell count automatically from the volta-
ge of the pack, but it is essential that you check the figure, and cor-
rect it using the INC / DEC buttons if necessary.
It is absolutely essential that you set this value correctly,
otherwise the battery pack could explode!!
Now press the ENTER button to start the charge process; the
charge current starts at 0.00 A and rises slowly to the set charge
capacity limit.
Please don't be surprised if the charge current you have set is not
reached, because the charger constantly monitors the battery vol-
tage in order to prevent the cells gassing.
At the end of the charge process the unit automatically reduces the
charge current, so that the battery is reliably charged to 100% of
full capacity.
2 4 s
During the charge process you can display the charge time and
the charged-in capacity by pressing one of the INC / DEC buttons.
23

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