CellPro 4S 3 Amp Model
 

Having been given a new but older CellPro 4S 3 amp charger I now need to figure out how to use it to charge individual 18650 cells instead of packs.

I am using 18650 batteries as external power sources for my Trail Cameras that use internal Li-Ion batteries as their primary power source. The 18650 external power configuration is four parallel connected unprotected cells in Protected battery holders. It works very well and greatly extends my cameras time between battery change outs.

Three questions:

I am new to Hobby Chargers and was wondering how I would wire up the holder and charger to charge the individual cells in a parallel connected holder? My initial plan was to use an unprotected 18650 cell holder that connects the cells in parallel and connect the holder to the charger. I didn't see any diagrams for this in the manual.

Could I charge the individual cells in series if using a MACPB7 Node connector pigtail assembly? This would require using individual battery holders so I could easily connect the positive, negative and 3 Node wires.

I have a new Multi4 coming as well so I assume it and the 4S would be wire up identically?

Thank you,
Bill Smith
NE Oklahoma

If you have individual cells, it's much easier to charge them all in parallel. Placing them in series requires that you also wire up a balancer cable. Your charger is set up for that, but the balancer cable is a lot more work. I do have wiring diagrams for balancing cables if desired.

What voltage and milliampere rating do your LiIon cells have? Are they 4.2 Volts at full charge? Just curious.

What kind of battery holder would you be using for the charging purpose? All of them can be charged in parallel at a total charge rate of an ampere or so.

I didn't think I could use the 4S to charge in parallel since it charges through the Balancing wires??

The cells are 3400mAH and they are to be charged to 4.2 volts at 1 amp.

I'd like to get the wiring diagrams for balancing cables.

I want to be all set up for parallel and series charging so I have both bases covered.

Holders
If charging in parallel:
http://www.fasttech.com/products/0/1...ith-lead-wires

If charging in series I guess I would have to use individual single battery holders and connect them to the 4S.
http://www.fasttech.com/products/0/1...ith-lead-wires

Thank you,
Bill

I just thought of something on your batteries. Are you discharging them all in parallel? Or, one at a time?

In either case, you are likely to wind up with different numbers of milliampere hours taken out of each cell. That will be an issue when charging them in series. Your Cellpro charger, when used with the balancing connector will balance all cells during the charging process, but it could take a long long while if your batteries are way out of balance. Like a day or two.

The higher powered Cellpro Powerlab 6 or Powerlab 8 chargers have a much better capability in rebalancing way out of balance cells, but those chargers are not cheap. (I've got two Cellpro Powerlab 8 chargers)

Charging them in parallel eliminates any balance issues during the charging cycle. Your Cellpro 4S charger specifies that it can charge up to a maximum of 4 Amps on from one to four cell battery packs. However, it is not wise to set your charging rate over the maximum charge rate allowed in any one cell. So, with perhaps a 1C maximum charge rate which most Lithium batteries can handle, your maximum charge rate for your cells would be 3.4 Amps. That would apply for charging one, two, three or all four cells. Just be sure to check on the maximum charge rate allowed on your cells.

If you can live with a maximum charge time of around 5 or 6 hours or so, what you all ready have will work just fine. Just charge in parallel.