Mh-C9000: R&A vs. Cycle

[Marc999]

Hi folks,

I've been playing around with my c9000 for awhile, using Break-In,Discharge & Charge modes. I currently have some underutilized 'Impact 2900' batteries [doubtful of that label], that had quite low values ~1700-1900 after a Break-in. I've read the instruction manual and apparently should be performing 3 R&A's, followed by another Break-in. That's fine; I'm currently performing 1st run of R&A. Charge rate: ~0.5C = 1400, Disharge rate: ~0.2C = 600.

R&A will take about 12 hrs [including rest]x3 = 36 hrs total, based on my charge/discharge rates. This time estimate doesn't include the manual Discharge after each R&A.

Would I be better off just performing 3 Cycles, to not worry about manually Discharging after each R&A, let alone babysitting to perform the 2nd and 3rd R&A?
I would use Charge at the end of the final Cycle.

I suppose I'm not very clear on the differences between R&A versus Cycle aside from Cycle ending in a discharged state and being able to perform multiple runs.
Would running 3 Cycles have about the same effect as 3 R&A's?

thanks,
Marc

 

[TorchBoy]

Maybe it's just me being cynical, but any battery claiming to be 2900 mAh isn't going to be truthful/accurate anyway, so perhaps you shouldn't be too surprised by an actual result of 1900 mAh.

To answer your question, I think I would just cycle them. You want to perform multiple runs without too much hassle.

 

[clintb]

I'm with TorchBoy. Think about it this way; the best performing, non-LSD, cells are PowerEx 2700, and even those don't test out to the rated capacity. I would take what the break-in gave you, in mAh, and use that as a baseline for the R&A or cycle. Break-in, after-all, is the most truthful method.

 

[Marc999]

Thanks guys, apparently working with these 'Impact 2900' AA cells was fruitless. It was more an exercise in playing around with the c9000.

I ran a Break-in on 4 cells: 1700-1900
1 R&A: 1750-1940
Discharge: ~ same as R&A
3 Cycles: 1760-1950. I noticed the first 2 cycles [cycle history], were available for review, but not the 3rd. Good to know.

So, I'm not seeing a 10% increase after this procedure. I think it's time to part with these cells and get back to my powerex 2700s and eneloops. The good news is, I watched the charger terminate each slot @ 1.47 volts, so at least I know that works.

I'll refer to previous posts regarding watching voltage at the 1/2 way discharge point, to be on the lookout for funky cells.

I'm noticing a large variation in charge/discharge rates from people in this forum. From absolute values for all cells regardless of capacity, to % of cell capacity. I've been using a 50% charge rate [0.5C-1.0C] and 20% discharge rate [0.2C] guideline.

Would I notice much difference in discharged amount, if I jacked up the discharge rate to 0.5C? I suppose I can try it out for fun and note the difference.

Marc

 

[TakeTheActive]

...I've read the instruction manual and apparently should be performing 3 R&A's, followed by another Break-in. That's fine; I'm currently performing 1st run of R&A. Charge rate: ~0.5C = 1400, Disharge rate: ~0.2C = 600...

...Would I be better off just performing 3 Cycles, to not worry about manually Discharging after each R&A, let alone babysitting to perform the 2nd and 3rd R&A?

If your intention is to run 3 R&As regardless, yes.

...I would use Charge at the end of the final Cycle...

Unnecessary. Every function except DISCHARGE ends with a Charge.

...I suppose I'm not very clear on the differences between R&A versus Cycle aside from Cycle ending in a discharged state and being able to perform multiple runs...

See above.

...Would running 3 Cycles have about the same effect as 3 R&A's?

Not if you add the manual DISCHARGE between each REFRESH. That would increase the effective cycle (i.e. Charge/Discharge pairs) count to 5 (2 times total R&As minus 1).

 

[TakeTheActive]

...apparently working with these 'Impact 2900' AA cells was fruitless. It was more an exercise in playing around with the c9000...

View it as a "Learning Exercise" - nothing wrong with that.

...So, I'm not seeing a 10% increase after this procedure. I think it's time to part with these cells and get back to my powerex 2700s and eneloops...

Don't TOSS / recycle them - USE / recycle them in clocks, remotes, thermometers, etc...

...I'm noticing a large variation in charge/discharge rates from people in this forum. From absolute values for all cells regardless of capacity, to % of cell capacity. I've been using a 50% charge rate [0.5C-1.0C] and 20% discharge rate [0.2C] guideline.

Would I notice much difference in discharged amount, if I jacked up the discharge rate to 0.5C? I suppose I can try it out for fun and note the difference.

I attempt to Charge at the higher end of 0.5-1.0C until excessive heat (from rising Internal Resistance) interferes. And, while I Discharge at rates other than 0.2C (i.e. 100mA to cycle all of the chemicals, break up any large crystals, etc...), I use 0.2C for comparisons.

IME, higher Discharge Rates result in lower Capacity readings, especially in older and/or lower quality cells. I believe that this is due to increased Internal Resistance.

Why don't you do a few experiments yourself and see?

 

[Marc999]

TakeTheActive, I wanted to attempt a revival of some powerex 2700s [dated 07-08], that have been more or less storage box queens. I've done a couple of break-ins giving results ranging from 2100-2350.

Since then, I tried your suggestion of charging at 2A and discharging at 100 mah to try and break up those crystals. So I set 5 Cycles on these 4 batteries. This was started last Sunday. The 5 Cycles are complete with results as follows:

Battery 1: 2239, 2160, 2125, 2109
Battery 2: 2168, 2022, 1960, 1917
Battery 3: 2153, 2103, 2061, 2080
Battery 4: 2351, 2316, 2298, 2281

I didn't get the results from Cycle 5, as it doesn't appear to be stored on the mh-c9000 [OHO].
I see a declining capacity with each cycle; what do these results indicate to you? I'd been using eneloops on a regular basis, so I neglected the maha cells for quite awhile.

Anything further I could do to these cells, or is this typical for neglected batts?

thanks,
Marc

 

[45/70]

Marc999, when I have cells that I've tried to revitalize, and they show what you're getting, I attribute it to separator degradation. The high capacity NiMH's have a proportionately thin separator compared to standard NiMH's, and are more easily damaged from non use, abuse, etc.

Most cells that I've tried to restore, that have been idle for long periods, end up with this diagnosis. It's pretty much "use 'em or loose 'em" with NiMH's, particularly the high caps.

Dave

 

[TorchBoy]

I didn't get the results from Cycle 5, as it doesn't appear to be stored on the mh-c9000

Wouldn't those be the figures that appear before pushing the up and down arrows?

[OHO].

YDS.

 

[jayflash]

OK ... please give my slow processing power a clue. What's R&A? In my case it might stand for recharge and abuse!

 

[bcwang]

OK ... please give my slow processing power a clue. What's R&A? In my case it might stand for recharge and abuse!

Refresh and Analyze

 

[45/70]

OK ... please give my slow processing power a clue. What's R&A? In my case it might stand for recharge and abuse!

Refresh and Analyze

Oh, I dunno bc, the way some of us here can attribute more discharges of our cells "analyzing" them than they get in actual use, I kinda like "recharge and abuse"!

Dave

 

[bcwang]

Oh, I dunno bc, the way some of us here can attribute more discharges of our cells "analyzing" them than they get in actual use, I kinda like "recharge and abuse"!

Dave

I fit in that category too. I have so many cells that I don't get to use most of them. So they end up spending more cycles "refreshing" than actually powering something. I still have cells that have only been cycled since bought years ago but never gone in a device, sigh..... I gotta stop buying new batteries but everytime they release something new.....

 

[SilverFox]

You guys crack me up...

Who would buy cells and wear them out testing rather than using them in devices...

Tom

 

[Face]

You guys crack me up...

Who would buy cells and wear them out testing rather than using them in devices...

Tom

bcwang, apparently

 

[jayflash]

Glad I'm not the only one with a few extra cells of various flavors. They're for "emergencies", but I'll bet you knew that.

 

[Marc999]

Well, good news. After the 5 Cycles @ 2000 charge, 100 discharge, I ran a break-in. Cell 1: 2445, Cell 2: 2415, Cell 3: 2342, Cell 4: 2204

Seems like that high charge, low discharge helped breakup some crystals. I can't say the week long Cycling was worth the time, but at least I'll be more adamant about cycling rarely used cells more often. It was a good learning experience anyway to see what happens to back seat betty batteries.

Marc.

 

[bcwang]

bcwang, apparently

Yup, I'm guilty. Anytime I see some new brand of cell at a reasonable price, I pick up a 4 pack. The biggest problem is ordering stuff online and trying to spread out the shipping I just try packs of batteries I never used before. Many times after doing some testing they turn out to be quite poor and then they just sit on the shelf until I decide to test it again to see if they are still ok or not. Many of the cells have aged to a capacity that is considered junk cells already.

I've been able to hold off that habit for a while now, seeing as I have too many cells. I don't have much of the latest batteries and I hope not to buy any unless I someday run out of cells. But this really sounds unlikely....sigh.

 

[TakeTheActive]

Well, good news...

...Seems like that high charge, low discharge helped breakup some crystals. I can't say the week long Cycling was worth the time, but at least I'll be more adamant about cycling rarely used cells more often. It was a good learning experience anyway to see what happens to back seat betty batteries.

:thumbsup:

Powerex 2700mAh AA [dated 07-08] |   #1    #2    #3    #4
---------------------------------+---------------------------
08/25/09 C9000 Break-In          | 2445  2415  2342  2204 mAh
08/21/09 C9000 Cycle5:  2000/ 100|    ?     ?     ?     ? mAh
08/xx/09 C9000 Cycle4:  2000/ 100| 2109  1917  2080  2281 mAh
08/xx/09 C9000 Cycle3:  2000/ 100| 2125  1960  2061  2298 mAh
08/xx/09 C9000 Cycle2:  2000/ 100| 2160  2022  2103  2316 mAh
08/xx/09 C9000 Cycle1:  2000/ 100| 2239  2168  2153  2351 mAh
08/xx/09 C9000 Break-In          |    ?     ?     ?     ? mAh

 

[Marc999]

:thumbsup:

Powerex 2700mAh AA [dated 07-08] |   #1    #2    #3    #4
---------------------------------+---------------------------
08/25/09 C9000 Break-In          | 2445  2415  2342  2204 mAh
08/21/09 C9000 Cycle5:  2000/ 100|    ?     ?     ?     ? mAh
08/xx/09 C9000 Cycle4:  2000/ 100| 2109  1917  2080  2281 mAh
08/xx/09 C9000 Cycle3:  2000/ 100| 2125  1960  2061  2298 mAh
08/xx/09 C9000 Cycle2:  2000/ 100| 2160  2022  2103  2316 mAh
08/xx/09 C9000 Cycle1:  2000/ 100| 2239  2168  2153  2351 mAh
08/xx/09 C9000 Break-In          |    ?     ?     ?     ? mAh

Well, it looks like Cell #3 and #4 have problems. I'm going away on a fishing trip tomorrow so I decided to discharge and charge up the powerex batteries. I Discharged the 4 last night @ default rates; 2 of the 4 banks showed 0 mah upon completion. I'd never seen this before so set them on Charge at default rates this morning. The same 2 banks showed up HIGH. Strange considering the results above, less than a month ago. I let the 2 batteries rest, then tried charging them in the maha-c204w. Same result, red flashing light...won't charge.
The good news is, I've got a dozen eneloops to power my gps, flash light and camera so I'm good to go.

Marc