[NSRCA-dist7] LiPo cell configuration

[James Oddino]

TP does have a 10s1p 5000 V2.  I borrowed one and flew a few flights  
on it, but it was before I had the CellPro.  It's performance was very  
good but it did seem to have balance issues on the TP 1010/210.  I'm  
going to be out of it for the next two weeks but I'll try to test it  
again when I get back.  Perhaps the CellPro will keep it in better  
balance.

Jim


On Sep 17, 2008, at 9:04 PM, Scott wrote:

> Hey Electric Guys,
>
> I'd be interested in what LiPo battery configuration you are using..  
> 5S2P, 5S4P, 5S1P... other. Why?.. read on. I believe the less "P"  
> you have in the battery the easier to balance and possibly the  
> longer life you will get due to better cell balancing before  
> charging. I have recently converted to a new cell by TP, some of you  
> saw this at the Hollister contest. The 5S2P, 5200 pack, is working  
> great. Jim Oddino and I checked the internal cell resistance, which  
> was around 3milli-ohms (if I recall correctly). This battery puts  
> out 156A burst, the older 5s4p, 5300 pack put out 109A burst. My  
> thinking is this, the lower "P" pack you have the easier to keep the  
> battery in balance. If you have a 4p pack, any one of the 4p cells  
> can degrade over time, causing the 4p 'bank' to not supply as much  
> sustained current - causing the whole battery to be weaker. Jim and  
> I played with a Cellpro 10S charger, and I think we concluded that  
> it would be difficult for any charger to determine if any one cell  
> in a 4p bank was going bad (you can only monitor the bank IR, not  
> the individual cell within the bank). However, if you had a 1p 10S  
> pack, you could easily tell if the cell was gaining resistance as it  
> aged. On a 2p pack, the resistance CHANGE may not show up as easily  
> as a 1p pack but much easier than a 4p pack. We are trying to  
> determine here when a 5S pack is getting weak (yes, we can see as we  
> fly - but if we could determine as it happens, perhaps we can  
> correct this by charging differently). Jim O mentions he has not  
> seen a battery with as low of internal resistance readings as the  
> new TP pack, which equates to more power, less heat in use, and I  
> hope longer life. I will mention here that my 5300, 5s4p packs have  
> lasted 2-3 years and many, many flights, but they are getting old..  
> and the new packs may last 3-4 years.. they are also around $250  
> each.. a reduction in price from the 5s4p packs. I believe even  
> newer technology will soon show us a 10s1p pack from TP - and some  
> may have this now from other manufacturers.
>
> I'd be interested in your opinions on this topic.
>
> Scott
>
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