I'm in Mesa. If you'd like to borrow my grid charger/discharger setup, you're welcome to it. You will need to furnish your own bulbs and light fixtures.

Stick testing is warranted once you've established a pack will no longer respond to grid charging/discharging. Given the high mileage and the duration of your IMA light, it's hard to say what your results will be.

I am in the process of developing an as-removed testing methodology that is showing promise on my own packs and spares. It starts with a foundation of a grid charge and deep discharge. Follow with an in-car charge to max SoC, THEN grid charge to top it off (mostly for time savings and potential improvements from the higher charge rate). Then operate it normally. Once you notice a significant deterioration in mileage, excessive recals or an IMA light, do a 12V reset and car-charge to max SoC. Remove pack, disassemble and test sticks at 20A discharge. the difference between good and bad is usually very obvious. They are easily sorted into a "good" group, a "meh" group and a "pure crap" group.

I have tried multiple variations of the stand-alone stick testing scattered about the interwebz and found sticks can pass a variety of bench tests with flying colors including 100A load testing, and they can still go to crap in a mere 2 weeks. What it's coming down to is evaluating the individual cells as they are the principal failure mode. Individual cells are either suffering from higher self-discharge or internal resistance - not to a dramatic degree, but to a degree that causes a consistent deterioration compared to their brethren over time.

Again, given that you're local, I'm more than happy to let you borrow my equipment. I might make you sign a waiver to the effect of, "this stuff was built by an idiot with no consideration for safety. I acknowledge that I am using at my own risk... "

I've only shocked myself a couple times. It hurts. But I was being really stupid.

 

I would love to borrow your setup. I'm going out of town for a few weeks, but after that would be great. Thank you.

 

Will the car be sitting the whole time? Might as well bring the pack over. Pulling the pack is the hardest part. Hooking it up and grid charging/discharging it will take me about 45 minutes... mostly because I check it obsessively.

You'll have a fresh battery ready when you get home.

 

That's awesome Steve. I can't believe you would do that for me!

I'm out of town until Sunday. Right now the pack is still apart. My son is using the iMax B6 to discharge/charge each stick. I showed him how to setup the charger and use your method of discharging 3 times at 1A-.5A-.2A to .1V and then charging to max. He has done 9 so far and 3 of them are suspect. The initial charges only got to 4123mAh, 3244mAh and one that only got to 144mAh. They all took charges up to the 6500-6900mAh after the discharges, so I'm hoping they are much better now.

I figured that with all my travel lately that I could do it the "slow" way with the equipment I have on hand and not have to build a grid charger. Should I finish with the way I have been going or just put it back together on Sunday and bring it to you on Monday?

Thanks again!

 

One thing about the Imax B6 is they will very frequently terminate charges early due to false delta V detection. If you have a genuine SkyRC, this probably isn't the issue, but the $25 Chinese knock-offs that are all over the place (including 14 of them in my house) definitely do. Essentially, if a charge terminates and the stick isn't warm to the touch at 100-120°F, then the charge cycle should be restarted. Sometimes, it helps to set the deltaV cutoff from the default of 4-5mV to 20mV. The best solution is to sh1tcan them and get a Turnigy Reaktor 300W.

when you say "9", do you mean 9 sticks (of 22) or 9 subpacks (of 11)?

The measure isn't how much they can take in charge, but how much they can discharge at high current. The B6 can't test this at all, and as above, its deltaV cut-off detection is flakey at best, which makes the charge numbers questionable.

Your choice. I don't mind doing it at all. Since some work has already been done, I recommend you charge each stick to delta V cutoff at 5A before assy into the pack. Set capacity cut-off to 7150 (1.3X capacity due to efficiency losses) and monitor temp if possible. Once they are comfortably warm to the touch, you can terminate regardless of what it says for capacity. What you should look for in that situation is a cell that is notably different from the rest... ±10-15°F... probably a problem and may mean that stick is suspect.

This will cut the initial grid charge time to probably 5-8 hours and I can have confidence the pack is reasonably top balanced. And you can top off all the sticks at 50W way faster than you can discharge them all at 5W with the B6.

Steve

 

Hi, can you help me to set up the right parameters to put in b6 charger for charge and discharge 2006 civic hybrid battery? I got the full pack already disasembled, i am tryin to figure out the right parameters to do do it in teh right way y aprecciate any help you can provide me; thanks in advance