GRAUPNER ULTRAMAT 18 Operating Manual page 35

Ni-MH discharge balancing program
N i M H b a l a n c e
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
o f f v o l t =
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
2
START
sec.
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
* * I N F O R M A T I O N * * *
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
B A L A N C E R C O N .
2
sec.
D C H
B L C 2 8 : 3 0
D C H
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
N M - 3 . 0 0 A 0 6 . 7 1 7 V
Ni-MH-Delta-Peak (-∆ ∆ ∆ ∆ ∆ Peak) trigger voltage
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
N i M H d e l t a - p e a k -
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
v o l t = 5 m V / c e l l
+
INC
The discharge balancing program does discharge and balance
up to 6 cells of a battery pack.
The final discharge voltage for the balancer can be set
c u t
within the range 1.20 ... 1.30 V using the INC or DEC
1 . 2 0 V
button.
The individual cells in a battery should be balanced before
+ -
the pack is charged, to avoid the possibility of individual
INC
DEC
cells being overcharged during the charge process. A
battery should always be balanced before being charged
if it has been stored for a considerable period;
connect the balancer plug to the charger to carry this out.
It is also essential that the voltage of each cell in the pack
should be higher than the set balancer final discharge
voltage.
If you wish to obtain maximum battery capacity, the
individual cells should be discharged to 1.20 V a few hours
- but no longer than two hours - before the next charge
process. If the voltage falls below 1.20 V, the battery cells
lose capacity, so the pack must be charged to around
60% capacity before being stored for a protracted period.
0 1 4 2 5
The program discharges the battery pack at a rate of 50
mA ... 5.0 A. Cells with a higher cell voltage are
discharged at an additional current of around 100 mA
(balancing current). The charger terminates the discharge
balance process once all the cells have reached the
balancer final discharge voltage (+0.01 V).
It is possible to adjust the trigger voltage (in mV per cell!) of
the automatic termination circuit for Ni-MH batteries.
However, Ni-MH batteries have a less pronounced voltage
drop than Ni-Cd cells, and a practical range has proved to
-
be 1... 25 mV / cell. If the trigger voltage is set higher, there
DEC
is a danger of overcharging the battery; if set lower, there is
a danger of premature termination.
We recommend that you carry out a series of test charges
to establish the ideal trigger value for your batteries. Start
with 5mV / cell.
35