ProgressiveRC Multi4 FMA Cellpro User Manual
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Storing packs
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For best results, LiPo and A123 packs should be stored at 50% of capacity. Use the charger’s
LiPo All Brands Storage Charge
preset to prepare LiPo packs for storage, and the
A123 All Cpcty Storage Charge
to prepare A123 packs for storage.
CAUTION: Be sure the storage preset matches the battery chemistry. Using the incor-
rect preset will damage cells.
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LiPo packs charged to 100% should not be cooled below room temperature. Cells at 90% or
less capacity can be cooled below 32ºF (0ºC).
How Auto Current Mode works
The Multi4 Charger’s Auto Current Mode (indicated by the charge rate Ax.0C) precisely moni-
tors individual cell fuel levels (cell voltages) in a LiPo, Li-Ion or A123 pack. If the charger de-
termines it is charging too fast, it slows down. Likewise, if it is charging too slow, it speeds up.
The charger adjusts charge current at one minute intervals throughout the charge cycle.
When charging starts, it takes a short time for the charger 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 adjusts 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, the charger 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 ac-
count a pack’s starting charge level, so topping off a 50% discharged pack takes only about 30
minutes.