In need of some basics - RC Groups
May 22, 2004, 11:24 PM
Elfi Flyer

# In need of some basics

I am fairly new to LiPoly battery packs, having used NiCads and NiMH's for some time now. I understand the configuration of a LiPoly battery pack is something such as: 3s2p, 1300 mAh. As I understand it, this example would describe a LiPoly pack made up of a total of 6 cells, each cell having 3.7 volts available (when suitably charged). Three of the 6 cells are connected in series, to provide 11.1 volts total for this 3 cell "pack". A second "pack" of 3 cells is also wired in series to provide 11.1 volts. The two packs (3 cells each) are then conneced in parallel, so the finished battery pack will have 11.1 volts available, at a total capacity of 2600 mAh. Not sure if this is correct.

What I have a problem figuring out is a 2s1p configuration. Is this two cells in series, with the two cells also connected in parallel? Don't see how this is possible without shorting out something. Same thing for 3s1p. I would like to see a diagram of these configurations, to better explain them. Pehaps someone could point me in the right direction to some literature, a website, or whatever that would help a newbie learn the wiring arrangements possible for LiPoly battery packs.

RD
Last edited by Doug Sipprell; May 22, 2004 at 11:25 PM. Reason: grammar
 May 23, 2004, 12:27 AM Dismembered Member... RD: You have the first part right. The nomenclature used is XsYp to indicate the pack. It's overkill when there are no parallel cells in the pack. Hence, a 3s1p pack is simply 3 cells in series. Brad
 May 23, 2004, 05:04 AM Registered User If you have a look round the forum you'll find this has been discussed many times. The xS1P terminology is unpleasant and technically incorrect but seems to have stuck. It may work better for you if you think of the xP part as the number of series connected packs which are connected together in parallel. As you correctly said 3S2P is 2 packs of 3 cells in series. 2S1P is simply 1 pack of 2 series-connected cells (obviously since there's only one it isn't really connected in parallel with anything which is why the terminology is rather confusing). Steve
 May 23, 2004, 10:34 AM Registered User It's not too late to lose the 1P. Whenever I talk about a series of 2 or 3 Li cells, I simply use 2S or 3S without the 1P. So far, no one has expressed a problem understanding what I'm talking about. On the other hand, the 1P confuses a lot of people.
 May 23, 2004, 10:47 AM Registered User can someone explain how to gauge what volts to use - meaning do you just look at your motor's max voltage capability and that is it?
May 26, 2004, 11:21 PM
Elfi Flyer

# Edified

Steve, Dave:

Many thanks for the clarification on xSxP. If you happen to recall a specific thread or message in the forum that goes into this in futher detail, let me know. I will try to search past posts to find what I can. Your info, however, has cleared up much of the confusion.

RD