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How Auto Current Mode works
Dual PowerLab 8x2
’s Auto Current Mode (indicated by the charge rate Ax.0C) precisely
monitors individual cell fuel levels (cell voltages) in a LiPo, Li-Ion or A123 pack. If Dual
PowerLab 8x2 determines it is charging too fast, it slows down. Likewise, if it is charging
too slow, it speeds up. Dual PowerLab 8x2 adjusts charge current at one minute
intervals throughout the charge cycle.
When charging starts, it takes a short time for Dual PowerLab 8x2 to determine the
correct parameters, so it may “hunt” for up to 30 minutes before it settles on the optimum
current. This is normal, and doesn’t harm the pack. The longer the charge, the more
accurate the calculation.
The plot below shows how Auto Current Mode adju
sts the charger’s current when
charging a 2.1AH pack at 1.0C Auto. Initially, charge current is 500mA (this starting
current is defined in the User Preset and is adjustable). Within a few minutes, Dual
PowerLab 8x2 increases the current, and it eventually reaches 1.0C (1.9A in this
example). This is slightly under the ideal 1.0C charge rate of 2.1A for this pack. Fuel rate
Auto charging is intentionally calculated to be slightly conservative. Current drops as the
pack reaches full charge (the charger changes to constant voltage mode). When charge
current drops to about 0.05C, the pack is fully charged. If the cells are balanced,
charging terminates. Termination settings are also controlled by the User Preset
parameters.
With the 1.0C Auto Current Mode, a fully discharged pack is charged to its nominal
capacity in about 60 to 80 minutes, depending on the state of imbalance. Auto Current
Mode takes into account a pack’s starting charge level, so topping off a 50% discharged
pack takes only about 30 minutes.
If you find that Auto Current Mode is not properly calculating the ideal charge rate for a
pack, that pack probably require a custom fuel table. See
for details.
IMPORTANT:
Auto mode bases its calculations on the “actual” capacity of the
battery pack which may not be the same thing as pack’s “labeled” capacity.
Over time, the same preset may charge the same battery pack at lower and
lower charge currents. This is because the actual capacity of the pack will
decrease over time. This is normal.
Summary of Contents for Dual PowerLab 8x2
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