as time (Min) and capacity (mAh). If in the charge mode, a 50-minute
50~80mA trickle charge will begin. After the trickle cycle, the charger will
automatically go into sleep mode. Press the “Start/Stop” button to reset
the charger. There is no trickle cycle after discharging.
14. If the battery is disconnected or a bad connection occurs at any time
during the cycle or before the charger is reset, an “ERR” message will
be displayed.
15. Once the “Stop” button is pressed and the channel is reset, all
settings of the channel and information will be erased except for the
current (Amp) setting.
Notes on Charging Batteries (NiCd and NiMH)
The SuperBrain 977 charger you just purchased is considered a Delta
Peak Charger. You may ask, “What is Delta Peak?” or “What is Delta Peak
Threshold?” Delta is a scientific way of saying, “change in”. As you charge
your battery you may notice that the voltage is consistently climbing. The
977 is constantly monitoring your batteries voltage looking for a peak
voltage. Every battery has a peak voltage, and when the battery reaches its
peak, it will start to drop off a little, or start to lose voltage. This is what the
977 is looking for, that small amount of drop in the peak voltage. This is
what tells the charger that the battery is fully charged.
Peak Threshold Settings (NiCd and NiMH)
While the 977 is capable of selecting the appropriate Peak Threshold,
which is somewhat conservative for NiCd batteries, you can manually set
the peak threshold for each battery. This is the “mV” setting on the 977. If
you set a higher value, this makes the 977 less sensitive, a lower value
more sensitive. If you use too high of a value, you risk over charging your
battery and damage may occur. If you set too low a value, you may under
charge a battery, or get “false peaks”, and it will not be charged to its full
capacity.
“What values should I use?” you ask. The peak threshold setting depends
on the type of battery being charged, and the number of cells in that
battery. For NiMH battery, you want to use a value of 5mV per cell. So for
instance, when charging a 7.2-volt NiMH battery, use a value of 30mV. (7.2
volt batteries have 6 cells in them. 6 cells x 5mV = 30mV) For NiCd
batteries, you can use a value of 7 to 10mV per cell. Just remember too
high a value may cause overcharging and too low value may cause
undercharge.
Charge Rates (NiCd and NiMH)
What about charge rates (amp setting)? For NiCd batteries, you can use a
maximum charge rate of: capacity times 3 for sub-C or larger cells, and
capacity times 2 for AA cells or smaller. For NiMh, use maximum charge
rate of: capacity times 2. For example, a 1500mAh NiCd can be charged at
4.5 Amps (1500mAh x 3 = 4500mAh or 4.5 Amps) For new batteries, a
lower charge rate is better. Capacity ÷ 2 would be appropriate. For
example, a new 3000mAh NiMH would have an initial charge of 1.5 Amps
(3000mAh ÷ 2 = 1500 mAh, or 1.5 Amps).
4
