"HIGH" cells with C9000

[OpenGuy]

Under these conditions, it's important to do a full discharge of the cells once in a while, or you will run into memory effect.

Oh I do. Last one was just two days ago.

 

[noisebeam]

Re: Attempting to Rejunvenate 2-Year-Old non-LSD AAAs...

Are you up for an 'Experiment'?

- You'll need something to use AFTER the C9000 finishes it's 100mA DISCHARGE since that's really a pulsed 1000mA DISCHARGE. An incandescent flashlight or a resistor will do - just don't discharge below 0.8VDC under load.

Yes. I am up for an experiment. This is the kind of 'fun' I wanted to have with otherwise near useless batteries. Nothing to lose but two useful slots on the C9000 for what could be a couple weeks. (that could be an issue)

Only part I need to figure out is what I quoted. I don't have any ready made devices that draw a steady power drain and give access to read voltage. I probably do have the parts in shoeboxes, battery holder, old 1.5V bulbs, resistors and a multimeter, but not the desire to fiddle a contraption up - that is real work. But if I did how often do I need to check loaded voltage and below what voltage do I need to get? I read .8V as the lower limit, not upper.

 

[TakeTheActive]

Re: Attempting to Rejunvenate 2-Year-Old non-LSD AAAs...

Yes. I am up for an experiment. This is the kind of 'fun' I wanted to have with otherwise near useless batteries...

Great! :twothumbs

...Only part I need to figure out is what I quoted...

...I probably do have the parts in shoeboxes, battery holder, old 1.5V ,bulbs, resistors and a multimeter... ...how often do I need to check loaded voltage and below what voltage do I need to get?

It's not an EXACT science - they're *CRAP* cells already!

For my AAs, I have a 1 AA Duracell 'Superman' Incandescent flashlight that came FREE with a pack of alkalines. Then, to my wife's utter disappoint, I have a pair of Sears Solar LED Lamps that take 1 AA that never reached the yard. For my AAAs, I have several 1 AAA MP3 players with automatic shutdown.

Look around the house - soldering 2 wires to an AAA battery holder and a 1 cell incandescent lamp isn't all that much work! I usually run these 'Experiments' when I'm sitting at the computer in the den for a few hours. That way I can keep 'glancing over' to check the status.

The reason you need 'more' is because of the way the C9000 discharges. SEARCH for my old (within the year) posts on 'Deep Discharge' and you'll see TEXT TABLES showing how many more mAh I get from my BC-900 @ 100mA AFTER my C9000 @ 100mA shuts down. Then, depending on how much Internal Resistance there is, I get more from the Superman and finally let it run overnight in the Sears LED.

Have fun!

 

[noisebeam]

I just realized that this 'experiment' assumes the c9000 will accept these AAA cells after a deep discharge. Right now it doesn't. I'll report out the impedance test voltages it reports out this evening.

I could use the 401fs to recharge (spec is 200mA for AAA in slow mode) after a deep discharge if the c9000 wont accept them. Or a old dumb charger I probably have in storage somewhere - those give a very low mA charge if they are spec'd to for ~12hr charge time, right? It may be on the back label.

 

[InHisName]

I could use the 401fs to recharge (spec is 200mA for AAA in slow mode) after a deep discharge if the c9000 wont accept them.

I don't have that one but do have a MH C-204F, I know its not as good as the 401, but when I bought that, the 401 wasn't made yet. I have done 5 cycles with bulb and re-charge on 204. I have made 'some' difference but not enough to make them useful yet. Most of the 8 still register HIGH !

I like the idea of experimenting too, just to see what can be done. I expect by summer the last of the 8 will be giving its last dying gasp and will join the others in the recycling bin. But meanwhile maybe I can learn something or two before I toss them.

 

[OpenGuy]

Perhaps it's important to begin the recharge slowly following a deep discharge.

I have this one data point using 4 junk NiMH AA. Following a deep discharge (to about 0.9 to 1.0 volt at very low current) I put the cells in my C9000 and started a 1000 mA recharge, recording the impedance check voltages.

At about 100 mAh charge, I terminated the charge, discharged them again (just using the 100 mA setting on the C9000), and recharged again at 1000 mA. The impedance check voltage of all 4 cells went up by about 0.1 volts.

Only three things happened to these cells between the two impedance check voltages: the partial 1000 mA charge following the deep discharge, the normal 100 mA discharge on the C9000, and the second impedance check. Since I can't imagine either of the latter two being responsible, that leaves only the first and blind bad luck. Since all four cells suffered the same fate concurrently, it's unlikely to be luck.

The impedance check increase appears to be permanent. I've run lots of discharges (partial and complete, but not deep) and recharges on these batteries since then, and there doesn't appear to be any trend in the impedance check voltages.

 

[noisebeam]

Re: Attempting to Rejunvenate 2-Year-Old non-LSD AAAs...

What would be interesting is to:

1. Purchase a new set of AAA Eneloops
2. Run a DISCHARGE @ 200mA on the C9000 and record the Capacities.
3. Run a C9000 BREAK-IN @ 800mAh and record the measured Capacities for each cell.
4. Run through your existing usage routine.
5. Instead of CHARGING the cells in the 401FS, run a DISCHARGE @ 200mA on the C9000 and record the remaining Capacities.
6. CHARGE the cells in the C9000 @ 400mA (0.5C)
7. If the 'Percent of Capacity Remaining' as measured in Step #5 is greater than 10%
   • Extend your usage routine correspondingly and go back to Step #5.
   • Else, use this usage routine as your new 'norm'.
8. Every 10th cycle, add a Deep Discharge after Step #5.
9. Every 30th cycle, after the Deep Discharge, run a BREAK-IN @ 800mAh

Looking forward to reading your results!

1. Done. They are now labeled N1-N4
2. Done: Performed a slot #4 impedance check voltage (IC) before and after the 200ma discharge, all discharges ended at 1.23V and took 196-197min
N1: IC: 1.66V, D200: 589mah, IC: 1.59V
N2: IC: 1.63V, D200: 580mah, IC: 1.65V (slight outlier in cap and IC)
N3: IC: 1.66V, D200: 590mah, IC: 1.62V
N4: IC: 1.60V, D200: 590mah, IC: 1.60V

3. Done. Ran a Burn In set to capacity of 800mah. All discharge portions of BI took 331-334min & ended at 1.46V. Then at least a few hours after BI was done another ICV test, results:
N1: BI800: 801mah, IC: 1.77V
N2: BI800: 785mah, IC: 1.78V (still a slight outlier in capacity)
N3: BI800: 797mah, IC: 1.74V
N4: BI800: 794mah, IC: 1.75V

That is as far as I've gotten. Batteries are now in PBSF lights (N1/N2 in one, N3/N4 in other) and will remain in there for about a month. I don't plan on ever performing deep discharge steps.

I am curious why the Impedance Check Voltages went up by 0.12V+

 

[bob_ninja]

Who has experimented on "fixing" HIGH cells ?

...

Has anyone else been experimenting with "fixing" HIGH batteries. What did you try ? and was it successful or not ?:candle:

C9000 is more sensitive to degraded cells, so don't bother with it. Just use other cheap chargers that are usually less sensitive.

I don't "fix" such cells. Instead, I shift them into the "special junk" set used for 2 specific applications:
- wireless mouse at work
- couple of lights at home

In both cases I don't mind loosing power suddenly and can easily swap in new cell(s). Also they have are fairly low current (especially wireless mouse) so voltage tends to hold up well enough.

They key issue is charging. For this "junk set" I always charge them either in my super slow Sanyo charger @200mA at work when I am present and can check cell temperature to make sure it doesn't miss termination, or at home @1A again checking on them from time to time. In other words, never charge them unattended.

Also forgot to mention, they go into kid toys where risk of loss is VERY high (toys may go away at some point without removing the cells). Again loss of power is not a problem in toys.

So I don't try to fix them. I simply slowly retire them until they are lost or become hopeless.

 

[IlluminatedOne]

I see i am not the only one that spends time trying to get old batteries working again lol. I was feeling a little mad spending time fiddling with some old batteries to get them working again.

I am trying to get some old Nimh AA's that i bought a while ago to stop reading HIGH on the c9000.
I got 4 of the 12 to start taking a charge and have been using them in some older lights and i am still trying to recover the rest when i have the time.

I also recovered some really old Nicad AA's which seem to still hold a charge of around 650-700mah which is pretty good going as they are rated at 800mah.

Also 16x 4ah D cells which i bought super cheap a few years ago, i hadnt been able to check there capacity until i just got a c9000 and used them in that, but as i tested a few of them i was suprised that the first two i tried got 3900mah or so each so now i am going through the rest and seeing which will be worth keeping.

Mainly i was going through all my old batteries and seeing which need to be recycled as i really hate throwing things out it they still have some use in them.
If the C9000 wont charge them i will just put them in another dumb charger and use them in less critical stuff thats low drain like others have mentioned.

 

[Mr Happy]

Cells have to be in really bad shape before the C9000 will refuse to charge them. I've never seen it, and I have run some really crap cells through it.

 

[Lite_me]

Cells have to be in really bad shape before the C9000 will refuse to charge them. I've never seen it, and I have run some really crap cells through it.

Then I must have some real crappy cells then, cause I have several that display "HIGH".

 

[Black Rose]

Cells have to be in really bad shape before the C9000 will refuse to charge them. I've never seen it, and I have run some really crap cells through it.

The ones that I have that the C9000 initially refuses to charge are AA & AAA nicads that have been abused all spring/summer/fall in solar landscape lights.

 

[TakeTheActive]

...I've never seen it, and I have run some really crap cells through it.

Geez, what are you - some kind of 'Rechargeable NiCD/NiMH Cell' Newbie? :nana:

Or maybe you just RECYCLE your *CRAP* cells before they even get to HIGH? :thinking:

I didn't keep good records 'back in the beginning' so I don't exactly know WHEN I bought my ~30-40 Rayovac 1600mAh AAs (for my herd of Furbys for when the grandchildren visit) but I'll guess that it was ~2000-2002 and all I had to MISTREAT them were ROV PS1 and PS3 chargers. In my book, the fact that they lasted this long is amazing.

The WORST cells I ever bought were 4 NEXcell 1800mAh AAs mail-order (12/17/02) - *THREE* CYCLES and they were DEAD! I wasn't as knowledgeable then as I am now *AND* my health had just taken a bad turn , so, I didn't realize the problem until much later . IIRC, I GOOGLE'd them and found a couple of 'hits' of other folks complaining about a 'Bad Batch' - but, it was too late after the fact for me to take any action.

The next WORST cells were the *FREE* ones that came with my La Crosse BC-900 Charger back in 12/06 from Amazon - pretty much *CRAP* from Day 1.

UPDATE: Now that I've added / reviewed my CRAP / HIGH / MODE / TRASH data, the 4 Sakar 2500mAh AAs that came with the Digital Concepts 150mA charger are probably WORSE than the La Crosse cells.

I've had some luck with 45/70's 'Deep Discharge' routine, but, it's really a 'Toss-of-the-Coin' - sometimes it works, sometimes it doesn't; sometimes WHEN it works, it doesn't last. So, unless you're blessed with LOADS of free time, just treat your cells properly from the 'Get-Go' and RECYCLE them when they turn to *CRAP*.

• Have I invested a GREAT DEAL of time in 'attempting' to recover *CRAP* cells? Yes
• Have I learned a GREAT DEAL from these 'Experiments'? - Yes :thumbsup:
• Knowing what I know now, would I do it over again? - Maybe...

________________________________________​

Some 'Data' for other 'Frugal' CPF'ers to compare against:

CRAP File #2:
=============
ROV ENV-Y: 1,2,3,4
ROV MTB  : 1,2,3,4
ROV ANL  : 1,2,3,4,5,6,7,8
ROV ONV-Y: 5,6,7
ROV NONE : A3,A4

HIGH File:
==========
ROV ONN-Y: 1
ROV ONS-Y: 1
Sakar: 3,4

MODE File:
==========
ROV ONV-Y: 1,3,8
ROV NONE : A1,A2

TRASH File:
===========
NEXcell: 1,2,3,4
ROV LNH-Y: 3,4,5,6
ROV ONN-Y: 2
ROV ONS-Y: 2
ROV ONV-Y: 2,4
ROV None : 
Sakar: 1,2

 

[Schermann]

Hey Maha, in yoUr next model issue for the C9000, can you give us the option to set the rejection voltage for the 'HIGH' determination?

This would greatly assist those of us with lots of Energizer AA's that always seem to register 'HIGH' but seem to recharge ok on lesser chargers...

 

[lwknight]

Being frugal is one thing but taking flak from a insubordinate cell is quite another.
They are cheap enough.

 

[czAtlantis]

I tried to drill a small hole in cell and add few drops of distilled water and close the cell by soldering and it works now excellent. Previously I got 2.3V now it is around 1.6V

Of couse it is just "project" and I won't use these cells because there is big chance they will leak but just to let you know it is possible

 

[Schermann]

I accidentally put an Eneloop AAA through the wash cycle with some dirty clothes!

Before it was perfect, now it reads 'HIGH'!

So water ingress seems to have wrecked the AAA putting paid to the suggestions that it's dryness is the cause

 

[Yamabushi]

So water ingress seems to have wrecked the AAA putting paid to the suggestions that it's dryness is the cause

Although crystal growth is the usual culprit, electrolyte dry-out can also cause high impedance. An excerpt from a GP Batteries techcnical paper:

"A common phenomenon to the NiMH battery is that the impedance increases upon cycling due to electrolyte dry-out, especially at the end of the cycle life. During overcharging, gases form and pressure builds up inside the battery;trace amounts of gas escape through the seal or vent hole, leading to moisture loss and separator dry-out."

 

[TakeTheActive]

Although You Posted on Aug 26th, and Not Apr 1st, This *STILL* Sounds Interesting...

I tried to drill a small hole in cell and add few drops of distilled water and close the cell by soldering and it works now excellent. Previously I got 2.3V now it is around 1.6V

Of couse it is just "project" and I won't use these cells because there is big chance they will leak but just to let you know it is possible

Although this was posted on August 26th, and not April 1st, it *STILL* sounds like an interesting / feasible 'Experiment' to add to my 'Round Tuit' List. :thinking:

Anyone who remembers me from my FLURRY of posts a few years ago (when I was spending HOURs per DAY reading the 'Batteries Included' Archives and creating my FAQ) already knows that I have plenty of *CRAP* cells to 'Experiment' with.

Thanks for doing your 'Experiment' *AND* posting your results.:thumbsup: :thanks:

P.S. The *EXTRA* EXCESSIVE FORMATTING *SHOULD* have jogged anyone's memory in case they forgot.

__________________________________________________​

OT Observation: Although I haven't logged onto 'Batteries Included' in quite some time (when I feel that I've finished learning all that I can on one topic, I bury myself in another new topic - currently it's HD Recorders and HTPC), I find it interesting to note that the *SAME* 'Asked-and-Answered' questions from *YEARS* ago continue to be asked today - while STICKYs and SEARCH continue to remain 'Unknown Entities' :shakehead

Thus, I must give credit to the "Old-Timers" (meant with the HIGHEST respect) that continue to patiently ANSWER these *SAME* 'Asked-and-Answered' questions from *YEARS* ago. :twothumbs :goodjob:

 

[Schermann]

Cold cells seem high but 2 mins on a dumb charger get them warm enough not to be rejected by the Powerex. Surely Powerex would 'test' cells for some mins before rejecting them, not!