Dragonfire

iTrader: (1)

Just got one of these gadjets and did some zapping a few days ago.... I found that tightning up the contacts then move the cell a little (rotate back and forth, back and forth, back and forth) to improve the electrical contact. Worked fine.

BTW: As gearless said, the cells that sparked should have less energy put through em so you might wont to do em again just to match em up with your other cells.

TSR6

iTrader: (5)

Gutter - It also depends on the matcher.

Orion & Peak use the Lavco matchers, so the numbers when cycled on CE equipment will be off by quite a bit compared to Orion/Peak labels.

Most matchers who use CE equipment will also vary in their matching procedures. You'll want to closely replicate the proccess they use on the CE matchers if you want to compare label numbers to cycle numbers.

The GFX is also slighly harsher as far as numbers go. They've improved the software and hardware. Still, they should be very close.

PitCrew

When I zap my cells, I just leave them built. Works fine. (side by side configuration. That way you are not heating the cells up, unsoldering, then resoldering.

ZER01

Gutter Ball, you can also use desoldering braid, it'll soak all the solder up off the cell that it can, I'd say +/- 90%. I use it alot to keep my motor tabs clean. You can find it any electronics store including radio shack, it's about $.99-$1.50.

antoniop

Some testing with PC data acquisition.

Test scenario:
GP3300 High Spec pack with 1 year of use (and abuse)

Red Curve - Charge 6 amp after bringing pack down to 0V on a tray
Yellow Curve - Zapped pack at 80V. Charged at 6Amp. Discharge pack before to .9V per cell
Blue curve - Charged at 6.5Amp. Charge as it is. 2 days after zapping

Tests on a GFX at 30A discharge. Trays used were Rayspeed and Trinity Real time.
Mounted saddle packs with long jumper wire and SMC gold bars.

This was the improvement in Average voltage on this particular pack
1,158
1,160
1,168

That's quite an improvement in my book.
The pack was 1.170 when new.
The run time seems to be directly related to the way we discharge the pack before charge. Notice that the highest run time was when the pack was brought down to 0, for a few minutes.

The spike you can see on the red and yellow curves is the point where the GFX measures AIR.

Gutter Ball

Well our Canadian Radio Shacks are no good. The three I went to said they no longer carry resistors (was going to try and convert a computer power supply) and they didn't have solder suckers of any kind Guess I'll have to see what other electronics stores we have around here...

On another note, all the packs that I zapped did show an increase in voltage, decrease in AIR and runtime was up or down on the packs I think I like zapping! I zapped some 2400's last night too, will cycle them tonight to see what numbers I get.

I guess I won't be too concerned with run time. Our outdoor races are only 4 minutes long anyway. Higher voltage and lower AIR.

Later guys. Thanks once again.

XCrash

Hi,

I've had good luck leaving the packs assembled but you have to make sure you have good flat contact between the contacts on the zapper and the batteries. Also cleaning the contacts with a wire brush and cleaning the solder joints with the brush helps considerbly.

Messy globby solder joints are going to be a problem, you can file the solder joint a little to show fresh metal and flatten it out if necessary.

Keep in mind everytime you unsolder and re-solder your battery you are doing damage.

Brian

ghuber

iTrader: (1)

Interesting results, just goes to show re-zapping DOES work. That's why we provide a service to re-zap used cells. The postive effect it produces usually wears off after a few races, mainly due to chemical crystals reforming inside the cell, but still it's a great way to extend the life of your packs.

The first time I used a zapper it scared the sh*t out of me! Shot a few huge sparks into the air, and burnt the hair off my right arm! Then I got wizened up started wearng a full face mask, gloves, and a long-sleeved shirt. Thank god I don't use that type of system any longer!

Oh and just be careful, bad or reversed polarity cells can explode and that can cause serious injury! Also, don't ever touch the contacts without making sure the capacitor is completetly drained! The capacitors in these units store enough energy (even when the unit is unplugged) to electrocute you, no joke!

Jared Kirkwood

Why was your charge amperage changed for the 3rd (blue) cycle? That in its self negates the data in the test.

antoniop

Well, not exactly.

The first curve is a significant image of what the packs did at 6 amps charge after discharging to 0V.
The same goes for the test after zapping.

The curves I got from other tests were very similar. The cells stabilized at each of these steps and didn't improve or got got worse.

That's why the 3rd try was at a higher charge. Following tests have a curve that follows the blue one point by point.
The effect may wear off, but for now after 2 cycles the discharge is a carbon copy of the blue curve.
It happens in all my packs (6).

From the first test I could see that 0V was the ticket to a little more time, zapping was the ticket for a little more AV and 6.5 the best combination I could get from both effects.

I saw somewhere in this topic that someone had made extensive testing with higher amp rates just to confirm the myth that it would give less run time and more punch.

Since I had made all the testing I could at 6 amps, and after zapping the cells stabilized in Voltage and runtime, I decided to have a go at a higher rate.

I must say that IN MY CASE with my 1 year old packs it gave excellent results.

Now I'm testing further with 6.5 with diferent combinations.
Traying to 0V
Traying at 5.4V
...and eventually zapping them again...

What I got from my testing was the clear notion that even with 1 year of use in competition some of these packs (if not all) will show the same values in voltage as the label shows lower IR and (the only thing I can't seem to reverse) a loss in runtime.

When my testing is complete I'll post the xls file with all the measurements in my site, or if the size does not exceed this site limits, i'll upload it here.

ghuber

iTrader: (1)

It is highly unlikely that you will see much further improvement in your cells due to zapping.. but you must understand the chemistry of a Ni-MH cell as well as what the changes that occur when zapping occurs.

Most information about Ni-MH cells and battery zapping is common knowledge amongs people who design these cells. With that said, let me put forth some information that was created by others which may help you guys understand the theory behind zapping and Ni-MH cells. Please keep in mind that at this point no one is absolutely certain why zapping works. At this time the majority of theories are based upon a bunch of conjecture, which seems to make some sort of sense.

First lets have a lesson in Ni-MH battery chemistry - The Ni/H2 cell was an adaptation of the NiCd cell that used the NiOOH electrode coupled to a H2 fuel-cell electrode in a pressurized, sealed battery. In a NiMH cell, the anode is a metal hydride electrode that serves as a solid source of reduced hydrogen that can be oxidized to form protons. The anodic half-reaction is:

MH + OH- = M + H2O + e-

thus the overall cell reaction becomes:

NiOOH + MH = Ni(OH)2 + M

The anodes are comprised of hydrogen storage metals: classic examples of these include Pd and LaNi5, but these are not used in NiMH cells for a variety of reasons (for example the cost of Pd). The anodes used in these cells are complex alloys containing many metals, such as an alloy of V, Ti, Zr, Ni, Cr, Co, and (!) Fe. The underlying chemistry of these alloys and reasons for superior performance are not clearly understood, and the compositions are determined by empirical testing methods.

The NiMH batteries retain many of the advantages of NiCd, including long cycle life, and are signifcantly superior to NiCd's in energy and power density.

The exact mechanism by which zapping works is unknown. What is know, however, is that cells build up crystalline formations, as they are manufactured and later as they are cycled. These crystals cause tiny bridges to form between the plates inside the cell. The more crystal formations the harder it becomes for the cell to absorb and release energy effectively. This is refered to as IR or Internal Resistance. A "Zapper" pretty much explains it's self. It's basically a transformer and huge capacitors that store up a very large charge and then releases it through the cell in a couple microseconds. This tends to shatter the crystals breaking down the IR in the cell and making it more efficient. Commercial zappers are very expensive and can pass as much as 30,000kva through a cell. There are less expensive "maintenance" zappers that put up to 90volts at up to 1kva through a cell to help keep crystals from building up.

In closing, you have to remember that cyrstal formations inside a cell start to reform after a few races. This is the exact reason why your new packs slowly start to loose their punch after 8 or so cycles. The crystals start to form inside the cell, thus increasing IR and making the path for electricity to flow less freely.

Still I'm interested in seeing what kind of results you can conjure up! Test and then post away!