Let's build a LiPo battery pack...

So reading through another thread (Read it HERE), I see where one can buy the LiPo cells, the balance charger wiring harness, and some details about how to assemble the LiPo cells into a pack fit for a heli...

My next question is, "How do I calculate the overall mAH of the collected cells in the pack?" I am guessing it is going to be straight up addition. For example, if I were to get 3 - 740 mAH cells and slap them together into a 3S (3 cells in Series)pack, would the overall mAH rating be 2200mAH (actually 2220). Similarly, using 850 mAH cells would produce a 2450mAH pack?

If this is the case, you could build the 2450mAH packs for around $15...

Now I need to go home and actually MEASURE to see if any of these configuations will actually fin in my Belt CP v2 and also compare the weight to the original LiPo.

If anyone has any insight, please share!

I may be wrong about this, and I probably am, but I think if you connect batts in series you increase the voltage and the capacity will stay the same. ( two 11.1, 2200 mAh packs in series would yield 22.2 v, 2200 mAh)

If you connect batts in parallel you keep same voltage and increase the capacity. (two 7.4v, 2200 mAh in parallel would yield 7.4v, 4400 mAh)

Someone else please chime in. I don't want to mislead anyone

Donnie D

Good call, DD!

I forgot my basic high school chemistry / physics. You are right, the voltage adds but the amps remain the same when in series. In parallel, the voltage remains and the amp add up...

No wonder it seemed so cheap to make a battery pack...

I found another link for the single LiPo battery cells, more in tune with the mAH that we need for some of out helis...

http://www.batteriesamerica.com/newpage8.htm

Cells are still to expensive to make your own but still a good option if you can diagnose a single bad cell and replace it rather than scrapping the two good cells...

You can also remove bad cell with bought battery pack. Just look which cell is bad and desolder it from circuit board. Of course some wires will need to be re soldered too