Which cells and where from?

[Mash Potato]

Looking at getting some new cells to run in my B44 (when it arrives).

From what I've read so far EP 4200 cells seem to be the best choice due to durability. Is this what you guys are finding, or do you have any other recomendations?

What suppliers do you recomend?

[sosidge]

No point in getting matched cells.

They are available for a little more than £30 a pack unmatched from many UK dealers. No need to look elsewhere.

They seem more reliable than the IB's to me and certainly don't lack anything in performance.

[mark christopher]

just make sure they will be legal for next year after the dimension changes

[JCJC]

Race Place ?

http://www.oople.com/forums/showthread.php?t=5941

[Martin-Barbour]

dimmension changes? cripes.....

[Mash Potato]

[quote=sosidge;70322]No point in getting matched cells.[quote]

Thanks for all the help guys.

I'm just returning to the 1/10th after quite a few years. Previously matched cells were the only way to go, so just interested in that statement.

[Richard Lowe]

Originally Posted by sosidge

No point in getting matched cells.

They are available for a little more than £30 a pack unmatched from many UK dealers. No need to look elsewhere.

Nick at Demon does his best matched EP packs for £35

The last set of EP42's I got from him have been fantastic

[super__dan]

I don't agree this the matching statement. Not wholy from a performance point of view but from durability from ensuring all cells in the pack peak and dump at the same time.

[notlawnomis]

It also depends on what level you race at as well, I've been using the same £20 unmatched packs of IB4200's without any problems for 2 years now.

[Northy]

But Dan, the trouble is the quality of the China cells is so shite, that even if you match them really well, they go out of match very quickly.

Do all the lights go out on your equaliser go out within a few seconds on your super team packs?

G

[sosidge]

Agreed, have had plenty of experience of various grades of matched and unmatched packs.

After a dozen cycles even the best matched packs will be out of match.

Some matchers may be inclined to fiddle the figures a bit, some will cook the cells to get the best numbers, some will use some pretty heavy-handed "voltage enhancement" techniques to get even better ones.

The tolerances between cells are very small as well. As long as your cells are not faulty (normally you will know as soon as you get them if they are not right as the resting voltage will be wrong) you will find very little difference between them.

Years ago among my GP3300s it was the unmatched sets that gave the best numbers on the ProTrak and lasted longer with good performance.

So for me, I will have my cells virgin from the factory, if anyone is going to mistreat them it will be me!

PS my unmatched packs (probably 20 cycles on each one now) open to any analysis against anyone elses super matched packs, just send me your pack and I will do some tests.

[super__dan]

Originally Posted by Northy

But Dan, the trouble is the quality of the China cells is so shite, that even if you match them really well, they go out of match very quickly.

Do all the lights go out on your equaliser go out within a few seconds on your super team packs?

G

They don't after sitting in my box for a week or two but in my mind that is due to the the varying self discharge. If I were to equalise, charge and then immediatly discharge then I would like to think it would be somewhere close.

I've never actually done this though.

Surely matching though (even if buying the cheapest packs) weeds out the very weak cells which are the ones you would get most concerned and over charging/over discharging relative to the rest of the cells in the pack and it's these that would be most dangerous?

[VintageRacer]

An interesting article here:
http://www.nrgdynamics.co.uk/matching.htm

[SlowOne]

Originally Posted by Northy

But Dan, the trouble is the quality of the China cells is so shite, that even if you match them really well, they go out of match very quickly.

Do all the lights go out on your equaliser go out within a few seconds on your super team packs?

G

In the main, the current draw on equalising boards is very low, so even a small difference in capacity at the end of a high-amp discharge will take quite some time to show. Just because the lights don't all go out together, deosn't mean the match is poor, just not perfect. To get the last few mAh out on a low current draw takes a lot of time, so that's why the lights take time to go out.

I've done what Super_Dan says (charge, use, discharge to 4.8v for the (4-cell) pack, then 'tray'), and it does make the lights go out within seconds of each other with a good pack.

I hope I'm allowed to recommend TJ Cells, from whom I have had IB4200 matched packs (no voltage enhancement) that are every bit as good as a well-known 'blue' pack costing more, and claims to be voltage enhanced. I'd recommend a word with TJ about what he has - his cells were fresh and full of voltage on arrival. I'd have thought his GP3700 cells would be right up your street. HTH

[GRIFF55]

Have you tried Niel Oliver on here, he makes good pack at a good price!!
www.Stormforceracing.co.uk
Hope this is ok Jimmy?

[RogerM]

I have to second the recomendation for Stormforce.

I had 3 packs of IB4200s (yes I know, bad timing!!!) from Neil at the weekend and I can honestly say I was as impressed with the performance as the price he charged me ... which was very reasonable, especially when you consider how much effort he put into getting me exactly what I wanted!!!

[Benh]

This is for all those out there as useless as I am am at maintaining and caring for cells.

GP Nimh 3700 are brilliant for people like me as they can be repeaked during the day (when you have left it to the last minute and do not have enough cells ready for the day), left with charge in, never equalised and still get great results from them.

Whereas Intellect 4200's are supposed to be very good, but in my hands, they turned to !@?# pretty quickly.

[Mash Potato]

Fair point, but where can you still get GP Nimh 3700's?

I see these guys list them: http://www.nrgdynamics.co.uk/cells_gp3700.htm

They say they don't have many left though, and it also states this about the cells:

These are old stock and fail to come up to the full 3700mah spec. but still perform as expected

[_JP_]

Can some one shed any light on this dimension change, what about all the Cells we have now????

Starting to get worried now!!

[Robfo]

Basically the IB42's will be taken off the list. The cells can be no more than 43mm tall throughout their lifetime, the IB's exceed this so they're gonna be illegal when the rule is enforced. Don't worry though because the IB42's are pretty much shot after 8 charges anyway so you'll need new packs for maximum performance.