NEWS FLASH

Well I must admitt haveing not opened my case on my 1s LiPo I'm thinking there is just 1 cell in side

I have opened several and I can confirm these are definatly 2 parallel cells:

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as above this is a 1s lipo ( saddle pack )

I think you will find that is in fact a 2S (2 cells in series) LiPo you have there, total voltage out the leads is 7.4V yes

Also I am not guessing as to the configuration of the cell as I have been on the manufacturers site and got the spec from there as I said above.....

Found the battery in the pic on Vapex's HK site [You must be registered and logged in to see this link.] and it is a hard case 1S2P with a balance lead pictured

I agree with the 2cells in parallel for 3.7v.... but we know that all ready, what we are missing is that all cells no matter what type discharge at slightly different rates due to internal resistance differences there for over time you have an imbalance in the cells weather parallel or not, some of you will be able to see this and some wont, this will mean that over time your packs will either false peak because one begins to top out before the other or you will end up sucking the life out of one of the cells over time and drop it below the 3.2v cut off point.(DAMAGE)

On the balance lead there is 3 wires yes, 1 common and 2 live 1 live for each cell, during the balance each cell is monitored separately and individually brought up to the exact same level thus balancing the pack.
A self balance wont ochre with a lipo because of the way the monitoring works so all lipo packs must have some sort of balance capability weather you use it is up to you but eventually the pack will loose its punch, you will still see the 3.7v your looking for but from the highest charged cell.

For anyone who really wants to know, look up lipo charging circuits for paralleled cells with balancing you'll see exactly what im saying.


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Hard to say Marti . . . .
But I have had mine for 18 months now and its doing fine I use the Pro-Trak at CC (constant current) and it carrys on charging till the pack is 4.20v take about 25 to 30 mins to charge.
Pack is 5000mah so charge at 5A

On the balance lead there is 3 wires yes, 1 common and 2 live 1 live for each cell, during the balance each cell is monitored separately and individually brought up to the exact same level thus balancing the pack.

I'll try to ignore for the moment the fact that 2 LiPo Cells in parallel cannot possibly go out of balance as their voltage is what balances them and they are directly connected in parellel so cannot be anything but the same voltage. Now where would you put the 2 "live" wires so that they could magically see the non existant difference between the cells?

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Is there no board in the packs that electrically disconnect the packs so the balance lead and sense circuit will actually work, i find that remarkable, your telling me that the tags from the cells are completely and directly connected together as in your diagram.
I was giving the manufactures alot more credit then they deserve then.
I have some balance circuits here, ill dig them out later and take some photo's of what we use on our equipment, we deal with alot of lithium cells and balance them all no matter what the configuration altho they are in constant use charge cycles so go out of balance alot faster then an RC pack would.

Is there no board in the packs that electrically disconnect the packs so the balance lead and sense circuit will actually work, i find that remarkable, your telling me that the tags from the cells are completely and directly connected together as in your diagram.

Exactly , with the high discharge loads we are asking of the cells it would be impractical if even possible and almost certainly not cost effective to have this sort of sense circuit built in and capable of handling 200+Amp load that the packs are rated at often! Just have a look at the 'soft' LiPo packs for RC planes and such which are the same thing just not shoved into a protective case and see if you can find any balance/protection circuitry.

FYI

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Nice 1 that's kinda made that clear enough