Excellent information here. I am currently 6 sticks into my pack and all seems to be progressing just as described here. So far all seemed to have recovered between 6180 and 6301mAH. Two sticks needed two cycles and one needed 3.

One question I have is why is the trickle set at 0.00 for 20.00 minutes. I had two sticks that finished the "charge" cycle at 6180mAH and was wondering if the trickle was set, would this have improved it even more?? Or can I just skip the trickle altogether and just hit stop and save myself twenty minutes.

 

Trickle should have no significant impact on capacity either way.

What is your discharge rate?

HCH2 cells are different than HCH1. They are rated at 5500mAh, and your higher than rated capacities suggest 1 of 2 things (or both).

1) you are immediately discharging after charge. This can produce artificially high results. Typical wait times are 20-60 minutes.
2) you are discharging at extremely low rates (<1A), and this will tell you nothing useful about the sticks.

I recommend you top off all your sticks, reassemble the pack and deep discharge the entire pack to less than 2V using lightbulbs. Assuming you don't have a grid charger, top off all your sticks again at 5.5A to delta V cut-off, reassemble pack and go.

The cycling of sticks is a waste of time especially if you're using low discharge rates. Search "voltage depression" and read my other posts.

 

S Keith,

Thanks for the reply,

So far my discharge rate has been hard to figure out. Discharging at 1.0amp took less than two minutes on all but one stick so far. The sticks were showing between 5.6-6.7 volts at the time of discharge. Mind you they were sitting in the car for a good two weeks or more and the car has been used sparingly before that, so my first thought was they were already pretty much discharged????

So your saying I can just top them up as they are. Put that pack back together and do a deep discharge on the entire pack. Can I use the Super Brain 989 to do that discharge or is there something light bulbs do that the 989 can't?

I will check out your other posts to educate myself a bit more on the subject. Bit out of my league here.

So if I have some sticks that are in bad shape, topping them off and then deep discharging them to around 2volts as you suggest, and then charging to 5.5A should take care of those -vs- cycling them individually. I am all for that idea as it would save time and headache of doing, stick by stick method. I am a bit worried as some of the sticks finished below 3000mAh on the first charge. Discharged again @ 1.0 amp and charged at 5.5Amp and the second go round they finished around 6180mAH. But I hear you about the false readings as well...could have very well been that I did not wait between cycles. 20-30 minutes tops

Thanks for the info...sounds like you have been there and done that.

 

So, you actually have a 989? Hard to find these days.

989 has a lot of deficiencies. Connections are not robust for the kind of use they get when using for hybrid battery stick cycling, and their cooling system is inadequate for 10A discharges of 5.5-6.5Ah sticks.

I directly soldered my leads to the board, and I removed the top cover and use a 1" hole saw to cut holes at both ends of the heat sink, i.e., now the fan can suck in at its end and blow out the other. The fan doesn't even run the whole time on a 10A discharge.

Lastly, the way the 989 reads the loaded voltage vs. the unloaded voltage, so if your sticks have higher internal resistance, they will crap out well before they're actually discharged.

I would concur that they are pretty much discharged. A 1A discharge should take about 5 hours, not two minutes. You likely have 1-2 cells per stick that are depleted and register a cut off.

The safest way is to set charger to .55A and charge for 10 hours (set cut-off to 15mV). You could do a pair that way, but it's still a time consuming process.

If you're in a hurry, charge each stick at 5.5A but monitor temps carefully. A cheap IR temp gun from harbor freight is handy. Don't let any cells get over 120°F and note if any are the hottest or coldest by more than 5-10°F. If you find 1-2 cells are lagging temp-wise, you probably need to charge at a lower rate, .55A for 4 hours or so. You can also strap them together in parallel.

The whole-pack voltage will kill the 989. It can only handle something like 30V (if even that). A light bulb is easy. You can fashion a discharger from a 2x6 and a couple ceramic lamp holders for a few bucks. Wire the holders in series and use 2X 200W bulbs until you get to 120V then switch to 60W and discharge to <2V... lower if you have the patience.

Nothing I am recommending will "fix" anything but voltage depression and imbalance. These things will eventually develop higher internal resistance, cycle-related capacity loss or excessive self-discharge. Nothing can help any of that, but regular grid charging can maintain balance when you're dealing with high-self discharge.

Businesses that operated under "refurbishment" options have all failed UNLESS a large portion of their business is replacement with new sticks and they have a massive selection of sticks from which they can salvage the best 25-33% of what is actually still good in a deteriorated pack.

If you're throwing an IMA light, you likely have no more than 8 sticks (4 pairs) that are performing acceptably. The others likely have 1-2 cells that have excessive self-discharge or high IR, and they will deteriorate in an accelerated fashion even after traditional or deep discharge "refurb" methods.

Head over to Insight Central and read-up on their "deep discharge" thread. It's the highest reward/lowest time option out there.

 

Is it anywhere in michigan I can get this done? I live in the Detroit area.

 

Anywhere in michigan (detroit) I can get this done?

 

I ended up buying a Hitec X1MF which is working really well, after I figured out how to use it. I'm about half way through the sticks I pulled out of my 2003 Civic. I ended up going down to my local hobby store, and this charger looked pretty good. I ended up bumping the limits up to 7500 mAh and 360 minutes, and I am cycling each stick 5 times regardless. I'm seeing an interesting pattern emerge, but I wanted to say that as I've watched this, some of the sticks increase in capacity going through the cycles, and a few decrease. They are ending up very close, which I'm glad to see. I've got the discharge and charge current set to 3.0 amps, but on the discharge it senses something, and cuts it back to about 1.2 amps to start with, and slowly increases to about 1.4 amps at the end of the cycle. I can see that the sticks in the middle of the pack are clearly more worn than the ones at the outer edge as I'm going through these. I'll see if I can paste in a screenshot of the spreadsheet I've set up with colors showing the degree of difference from the average.

Hmmmmmm...............

Looks like I'll have to put a screenshot up somewhere and put in the URL.

I'll work on that. Maybe I'll wait until I'm done with them all.

 

It doesn't sense anything. It's power limited. It's because you bought a toy charger. Those can only discharge at 8W:

http://hitecrcd.com/products/charger...harger/product

There is so much information out there dispelling the myth that this low current cycling is effective. It still boggles my mind that people follow these outdated processes. Just two posts up, and in every post with my signature, I refer you to better methods.

1.4A will tell you absolutely nothing about how the stick will perform at 100A.

If you're doing this because you've noticed an increase in recals or a decrease in performance, without an IMA light, you will likely see some benefit, and it may last a while. Depending on the issue, you'll probably reconsider the effectiveness of this procedure when performance starts to deteriorate again in the next 3-6 months and you'll need to take the car down for another 29 days.

Based on my calculations, you're taking 35 hours to do 5 cycles assuming 6000mAh capacity. 35 * 20 = 700 hours = 29 days assuming your charger never sits idle.

The "pattern" you describe is indicative of bad sticks. The ones that are increasing in capacity are shedding tiny bits of voltage depressed capacity with each cycle. The ones that are deteriorating likely have a damaged cell.

I'd much rather have been done with it in a weekend with either grid charging/discharging or high current testing.

I urge you to do the following so this isn't all for naught...

1. Increase charge current to 6.5A
2. After a SINGLE cycle, repeat the discharge and set to 0.2A and terminate at 3V. This single deep discharge will reclaim more capacity than 4 more cycles.
3. Procure one of these:

http://www.harborfreight.com/100-amp...ter-61747.html

Load test a freshly charged stick 30minutes or more after charging. Apply the load tester for 30 seconds and record the final voltage - do not let them drop below 5.4V. If one hits 5.4V, terminate load and record time.

You will likely identify 3-6 sticks that are weaker than the others.

Good luck,

Steve

 

I've actually got one of those load testers. After I get though these with my toy charger (only 2 to go) I'll run this test on several of them and let you know what I find.

 

You need to run the load test on all of them.