# matching lipo's



## munchi (Sep 22, 2003)

is there a need or is anyone matching lipo's? just wondering since lipo's are not supposed to be discharged. and if they are matching lipo batteries.. has anyone heard if competition electronics will come out with an update for their current matchers and the 4/35 matchers?


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## swtour (Oct 8, 2001)

Munchi,

Not much you can do to "MATCH" lipos in a sealed case... You can charge/discharge them (No lower than 6.0 volts on a 2 cell pack) and compare and/or look for the BEST pack. Most "LIKE" packs are pretty darn equal from what I've seen and been told.

A balanced pack may show a little better than a pack that is out of balance. (I think a balance charger for 4 cell would have been SWEET.)


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## 98Ron (Jun 14, 2004)

I believe I read that SMC was going to be cycling there lipo and labeling them with runtime avg volts and ir, just like sub c's. Perhaps that is what is ment by matching.


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## S. Jerusalem (Feb 21, 2007)

98Ron said:


> I believe I read that SMC was going to be cycling there lipo and labeling them with runtime avg volts and ir, just like sub c's. Perhaps that is what is ment by matching.


They currently are labeling packs. Or more accurately, the box it comes in. Pretty boring read. All the numbers are the same.


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## guver (Jul 31, 2002)

I believe that Vampower and Apogee are matching cells in packs. It is a very good thing. Many others may do it or use cells that are factory tested/labeled. It seemed to be somewhat of a "taboo" subject a year or two ago when I suggested a businness of Lipo matching.


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## munchi (Sep 22, 2003)

*matching*

i wanted to know basically because i have five of the 4/35 matchers and just wanted to know if it does actually happen that lipos get matched.... wondering if ce will update my matcher's so i can match lipo's.


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## pup1970 (Apr 2, 2008)

I can see matching if the cases can be taken apart, or if the cells are loose and they build their own. I don't see where matching could be much advantage since you can over voltage the batteries and charge each cell individually. I can only see runtime as being the matching game. If I am wrong, sorry.


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## munchi (Sep 22, 2003)

*matching lipo*

i honestly do not know enough about lipo's so i was just curious. it seems as if the equipment these days makes circles... it will be in one year and out then back in so... i love that ce has upgrades for all of their equipment so that always helps. just trying to get as much info as i can on lipo batteries.

thanks


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## RPM (Dec 20, 2004)

*Matching lipo cells is redundant.*

Most tracks have a voltage rule of *8.45 volts*.

*Whats the point??*


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## hankster (Jan 1, 1998)

In any multi-cell pack, matching could be an advantage. A 7.4 volt LiPo pack has 2 cells. If one of those cells had a discharge time of 500 seconds and the other cell had a discharge time of 450 seconds, then in that "unmatched" pack you could overdischarge one of the cells if it was run down to the recommend 6 volt cutoff.


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## pup1970 (Apr 2, 2008)

hankster said:


> In any multi-cell pack, matching could be an advantage. A 7.4 volt LiPo pack has 2 cells. If one of those cells had a discharge time of 500 seconds and the other cell had a discharge time of 450 seconds, then in that "unmatched" pack you could overdischarge one of the cells if it was run down to the recommend 6 volt cutoff.


Hank, I understand what you are saying about the runtime difference, but would there be a performance gain for the normal race, short of when the battery falls off?


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## guver (Jul 31, 2002)

The best performance would be the sum total of the two cells , so the unmatched pack could be worse or better. It would just depend on the average voltage of each pack. It is identical to NI matching if done the same way. Much easier though as you only have to find pairs or triple for racing. (maybe racing only allows pairs?)

Not counting when they run out of course. Hopefully racers aren't using them up that close to empty.


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## hankster (Jan 1, 1998)

pup1970 said:


> Hank, I understand what you are saying about the runtime difference, but would there be a performance gain for the normal race, short of when the battery falls off?


 
As long as you use a balancer to completely charge both cells individually, then there should be no performance penalty.


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## guver (Jul 31, 2002)

Trackpower/Flightpower is also matching apparently. The amount of imbalance at the end of the run is a dead giveaway.


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## Danny-SMC (Sep 28, 2001)

Most Lipo manufacturers match the cells by capacity and IR. The cells used in all our packs are matched and we take this step even further by cycling every pack in house to make sure they meet our minimum spec. This means our customers know what they are paying for.


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## guver (Jul 31, 2002)

Thanks, Danny. Would it be correct to think that ONLY capacity need be equal to have a balanced pack when discharged to 3.7 volts?

In otherwords, if the IR and/or voltage were dissimilar , since the cells are in series they would still be in balance at the end of the discharge?


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## Danny-SMC (Sep 28, 2001)

Yes that is correct.


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