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sedonakevin
08-26-2005, 07:07 AM
Hi all,
I've been looking at chargers and many say they will charge 1-4 cells,
how do you charge , for example, a battery pack that is 3S2P, isn't that a pack made up of 6 cells? I did notice the Astroflight 109 charger will charge from 1 to 9 cells, is that what I need to charge larger battery packs, or is it easier to connect 2 or more smaller packs? thanks for the help

Kevin

Geoff_Gino
08-26-2005, 01:12 PM
Hi Kevin

All chargers look at the cells in the S part of the battery description. i.e. 3S2P will be seen by the charger as a 3 cell pack even though there are 6 cells in total.
Two of these cells in series will be 6 cells to the charger so the Astroflight 109 will be able to charge 3 packs made up of 3S2P batteries connected in series.

Geoff

Geoff_Gino
08-26-2005, 01:35 PM
Hi Kevin

Geoff again. Perhaps the easiest way of remembering the cell count and configuration for LiPo's is this:- a single LiPo cell delivers 3,7 volts at a given current, now connect another cell in series to this for 7,4 volt, and another in series to those for 11,1 volt. All the cells must be of the same capacity (i.e. the amount of amps it can deliver). The P in the battery description is the number of cells connected in parallel, this is done to increase the capacity of the pack. Please feel free to PM me if you would like more info.

Geoff

Matt Kirsch
08-26-2005, 06:42 PM
I'll go ya one better. Here's the mnemonic I suggest to people:

Sells (cells) in Series.
Packs in Parallel.

The pack's voltage is determined by the number of cells in series. This is the setting you use for cell count on the charger.
The pack's capacity is determined by the number of packs in parallel. This is the setting you use for charge rate on the charger.

For example, take a 3S2P pack of 2000mAh cells. There are six cells total, arranged in two separate packs, each having three cells connected in series. The two separate packs are combined in paralllel (+ to +, and - to -) to combine their capacity. The final pack has a nominal voltage of 11.1V and a capacity of 4000mAh.