# Do You Maintain *CRAP* NiCD/NiMH Cells?



## TakeTheActive (Nov 21, 2009)

**CRAP*:*
- meaning their current Capacity is *LESS THAN 80% of their 'Originally Stated Capacity'* (as per *SilverFox*  ).
.
*NiCD/NiMH Cells:*
- meaning a SUBSTANTIAL (~40% or MORE!) of your total cell inventory.
Basically, I'm looking to see if there's ANYONE besides *ME* READING the CPF 'Batteries Included' Archives *AND* EXPERIMENTING with their *CRAP* (i.e. formerly abused, neglected, overcharged, 5/10/15+ year old etc... *BEFORE* they bought a *'SMART' Charger/Analyzer*) NiCD/NiMH cells.

*IF* you decide to reply to this POLL, please post:
Your (Active *AND* Inactive) CHARGER inventory.
Your (at least approximate) *CRAP* cell inventory (i.e. Manufacturer / Chemistry / Capacity / Age / Number of cells).
Your current MAINTENANCE procedure(s).
Your SUCCESS / FAILURE picture.
Note: I recently  at *PeAK* for a *LACK OF MEMBER PARTICIPATION* in his new thread: *Test for how well batteries suit your charger*. So, *IF* CPF Members are interested in '*INTERACTIVE*' threads like these, you need to *ACTIVELY RESPOND!* :huh: :duh2: oo: :tired: :sleepy:  :shrug:


----------



## TakeTheActive (Nov 21, 2009)

*Chargers: *
*Active*​
Maha MH-C9000 0H0AA
La Crosse BC-900 v33
RadioShack 23-428 Universal Battery Charger (Smart; AAA/AA/C/D/9V)
Rayovac PS23-B
Duracell CEF-23 Mobile Charger
Rayovac PS3 (Smart; AAA/AA/C/D)
Digital Concepts CH-1800 Digital Camera Charger (SAKAR Dumb 150mA Series AA/AAA)
RadioShack 23-418 13 Hour NiCd/NiMH Charger (Timed 140mA Series AA/AAA)
DieHard 93558 7-hour Fast Charger (Timed; AAA/AA/C/D/9V)
*Inactive*​
Sanyo MQN06U
RadioShack 23-250 Universal Battery Pack Conditioner/Charger (Maha MH-C777 clone)
Rayovac PS1
Saft Again and Again (Dumb; AAA/AA/C/D/9V)
GE ??? (Dumb; AAA/AA/C/D/9V)

*Cells: *
*AA - *CRAP**​
_4 La Crosse 2400mAh NiMH (12/xx/2006)
_4 Rayovac 2000mAh NiMH (2004?)
28 Rayovac 1600mAh NiMH (1999-2001?)
_4 Rayovac 1300mAh NiMH (1999-2000?)
_8 RadioShack 1300mAh NiMH (2002-2003?)
_4 Sears DieHard 1300 mAh NiMH (2002-2003?)
*AA*​
12 Sanyo Eneloop 2000mAh LSD NiMH (12/31/08, 05/08/09)
_4 Duracell Duraloop (MIJ) 2000mAh LSD NiMH (11/xx/08)
_6 Duracell Durabrid (MIC) 2000mAh LSD NiMH (09/19/09, 10/24/09)
_8 Kodak 2100mAh LSD NiMH (11/xx/08)
10 RadioShack 2000mAh LSD NiMH (09/xx/2008)
16 Rayovac 2000mAh I-C³ NiMH (2005?)
20 Philips 1400mAh NiMH (2004?) (Sanyo? Lime-green wrapper, no button)
_4 Sanyo 1700mAh NiMH (2002?)
*AAA - *CRAP**​
_4 La Crosse 800mAh NiMH (12/xx/2006)
12 La Crosse 700mAh NiMH (12/xx/2006)
_4 Energizer 700mAh NiMH (2004?)
_4 Rayovac 700mAh NiMH (2004?)
*AAA*​
_2 Sanyo Eneloop 800mAh LSD NiMH (05/08/09)
_8 Duracell Duraloop (MIJ) 800mAh LSD NiMH (09/03/09, 09/19/09)
_4 Duracell Durabrid (MIC) 800mAh LSD NiMH (10/24/09)
_4 Kodak 850mAh LSD NiMH (05/27/09)
32 RadioShack 750mAh LSD NiMH (09/xx/2008)

*D*​
_6 Vinic 6000mAh NiMH (2002?)
_2 RadioShack 4500mAh NiMH (2004?)
_2 Energizer 2500mAh NiMH (2002?)
_2 Energizer 2200mAh NiMH (2000?)
_2 Maxell ???mAh NiCD (1998?)

*C*​
_4 Tysonic 4500mAh NiMH (2002?)
_4 Millennium ???mAh NiCD (1998?)
_3 GE ???mAh NiCD (1994?)

*Maintenance Procedure: *

BRIEF Version (Cell Inventory took a *LONG* time).

I used to COOK my cells, starting with the Saft Again and Again, then the Rayovacs PS1 ("cool" COOK - missed terminations @ 200mA) and PS3 ("Hot" COOK - high internal resistance, missed terminations @ 500mA), and finally with the La Crosse BC-900 running 200/100 REFRESHES.

Today, I track *Impedance Check Voltage* and CAPACITY @ 0.2C with the C9000. When I find cells with an Impedance Check Voltage over 1.60VDC, I attempt to lower it via the *Cell Recovery* techniques listed in my Sig Line LINK (such as the *Deep Discharge Technique*). This process may take 10-20 REPETITIONS, so it's something you do when you're doing something else in the same room and can keep 'checking progress'.

As *PeAK* mentioned in his reply, *Internal Resistance* plays a major role in getting the CAPACITY out of your cells. And, the C9000 makes it EASY to track. Cells that read:
'HIGH' go to remote controls, non-critcal flashlights.
~1.80-2.00VDC go to thermometers, clocks, etc...
<1.80VDC go to non-critical, but high current, devices (i.e. GPS, camera)

I've measured and recorded the current draw of most of my devices and I attempt to utilize MATCHED CELLS with a ~2-3 month "CAPACITY to Power". Then, at either ~90 days, or when the device shuts down, I run a 100mA DISCHARGE on the BC-900, followed by a 0.5C (watching the heat) CHARGE on the C9000 - 25% if the cell's going into storage / rotation, 100% if it's going back into service.

*Success/Failure Results: *

BRIEF Version (Cell Inventory took a *LONG* time).

*45/70's* '*Deep Discharge Technique*' has worked on most cells, dropping usually ~0.1VDC, sometimes more. It's also important to be consistant and pay attention to WHEN you perform the '*Impedance Voltage Check*' - it varies by cell temperature and 'State-of-Charge'. 

A "*Forming Charge*" also plays a major role. I've CYCLEd cells 5-10 times on both the C9000 and BC-900 (0.5-1.0C CHARGE; 0.2C, 50% of CHARGE or 100mA DISCHARGE) and recorded either no improvement or DECREASED CAPACITY. Then, on a whim, I tried a "*Forming Charge*" (or two) and the CAPACITY increased a bit (nothing EARTH-shaking).

...to be continued... WHEW!


----------



## Henk_Lu (Nov 21, 2009)

While I've been using Eneloop type batteries (Panasonic Infinium) for over 3 years now, I'm still completely new to this...

The 2-cell charger provided by Panasonic should be a smart one, but I think it sucks. I often had problems that a light worked for 10 minutes and then switched to Low, once pretty new cells vented and I had trouble opening the Fenix L2D-Q5. In the GPS those cells normally last 12 hours or more, sometimes they died within 2 hours. No cell could be identified as "bad" though. I started "double-charge" them, when the charger has finished, I put them in once more in the other bay, the charger may take another 5 hours to complete. The charger had been replaced by the same model, same result.

So, I recently bought a Titanium 8800 AA/AAA charger, when I have it, I will recycle and test all cells, bad ones will be eliminated and replaced if I can identify them. I guess my procedure could have hurt them over the years, no idea, my knowledge od these things lacks. I hpe that charger qualifys as a smart charger. I'll also start with Li-Ion, but I guess that isn't asked here.

Sorry for the slight off-topic, if it is... :candle:


----------



## PeAK (Nov 21, 2009)

TakeTheActive said:


> Your (Active *AND* Inactive) CHARGER inventory.
> Your (at least approximate) *CRAP* cell inventory (i.e. Manufacturer / Chemistry / Capacity / Age / Number of cells).
> Your current MAINTENANCE procedure(s).
> Your SUCCESS / FAILURE picture.


 Here you go:


Your (Active *AND* Inactive) CHARGER inventory.
*Active:
-*Meijer/Camelion BC-905 *: *smart/negative delta-V/fast/independent channels*
-*Multiple Power" MP-809* : *smart/non-negative deta-V/Slow/independent channels (under evaluation)
-Radio Shack 23-425 : smart/0-dV/medium speed/Two batteries at a time
-Home made variable power supply (2 to 20V). 10 mA constant current source capable of sourcing up to 30 volts.

*Not Active:*
-Panasonic BQ-4B : dumb/slow overnight /two at a time
-Radio Shack 23-427 : dumb/slow overnight/two at a time
Your (at least approximate) *CRAP* cell inventory (i.e. Manufacturer / Chemistry / Capacity / Age / Number of cells).
See this link for my inventory of 47 NiMH cells as of Jan '09. Since then it has expanded with 8 eneloops and 8 no-name Eneloop.


Your current MAINTENANCE procedure(s).
The capacity is over-rated. I'm interested in how long the battery can maintain a voltage so that my Digital camera does not shutdown. So regular "on-resistances" is a key measurement to determine which cells make it to my "non maintained crap pile".
Your SUCCESS / FAILURE picture. 
The chargers all work great with the few NiCads that I did not damage with the dumb chargers. Similarly, I have excellent results/life with older/lower capacity cells less than 1400mA-hr. The worst cells are the large capacity (2200/2400/2600/2650 mA-hr) cells. I'm very happy with the lower capacity path that is being taken with the LSD cells.
Current Charger Evaluation: 
One of the latest promising discoveries that is under evaluation is a "smart charger" that does not use negative delta-V (Multiple Power MP-809). Here are the specs:


Constant 250 mA up to 1.41V
Switch over to trickle charge of 25mA for one hour and stop. 
Update: The above was found to be false as the unit was found to maintain a 100mA charge to beyond 1.8V forever. For now stay away from this charger


----------



## Black Rose (Nov 21, 2009)

My regular use NiMh AA/AAA cells that were CRAP went to the recycling depot this past summer. There was about a dozen of those.

This post isn't really what TTA was looking for, but I answered yes to the poll and am tossing in my 2 lumens, as what I do is very similar to what someone would do with CRAP cells.

First the chargers...

*Active Chargers:*
Maha MH-C9000
Maha MH-C800S

*Occasional Use/Backup:*
Eneloop NC-MDR02NU
Rayovac PS16

*Not Active:*
Sanyo NC-452B (Cadnica AA charger from the mid-80s)

*Not Active (but pulled into service in extreme cases):*
Rayovac PS13 (22 hour timed dumb charger) 
This is the charger that did most of the damage to my older cells, but it still has it's uses (at least until I get a hobby charger)

OK, onto the batteries.

*Inventory:*

All of these cells are used in solar lights over the spring/summer/fall and get beaten up pretty bad.

*NiMh:*
IDC AAA - 4 - 600 mAh - Currently about 55% capacity

*NiCd: *
I haven't had a chance to put these on the C9000 to get capacity numbers, but based on last years results, these guys are in the 30 - 40% capacity range, if not worse.

Unknown AAA - 3 - 350 mAh - 
Unknown AA - 2 - 600 mAh - 
IDC AA - 3 - 600 mAh - 
Paradise AA - 2 - 300 mAh - 
Lumisol AA - 1 - 600 mAh - 
Moonrays AA - 2 - 600 mAh - 
Golden Sun AA - 12 - 600 mAh - 

*What I do with them....*

Last week I pulled 4 600 mAh NiMh AAA cells out of a set of our solar lights to work on in the off season. 
These guys were pretty much empty since the sun decided our back yard was not worthy of it's presence :nana:

I put them on the C9000 to drain them @ 100 mA. Only one had any charge left in it (70 mAh).

Put them in to charge at 200 mA to see how they would do. No HIGH from the Maha, so that was a positive. 3 of the 4 terminated normally, one missed termination. Discharged and repeated charge 2 more times. At this point they are showing 350 mAh capacity. 

I will follow this regime with all of the above listed cells until they show better numbers. 
Once they show progress on the C9000, they get drained and then over to the C800S for a slow condition cycle (if they have enough capacity to handle a 500 mA charge).

For any of the above cells that show HIGH on the Maha chargers, they get a few hours in the Rayovac PS13 dumb charger before they get discharged and a charge is attempted in the C9000 again.

Once I get the hobby charge (Turnigy Accucell 6), the PS13 will most likely be retired.

Why do I do this instead of simply replacing the cells? I'm cheap  

These cells are expensive to replace at retail, web stores that carry equivalent cells have expensive shipping, and the only other place I know that has equivalent cells has a less than stellar rep for cell quality (why replace crap with crap?)

Besides, I have these chargers...may as well use them.


----------



## Lynx_Arc (Nov 21, 2009)

chargers active
rayovac 1 hr
BC900
Duracell Mobile

cells:
12 AA 12AAA duraloops about 4-18 months old
16 AA 12AAA rayovac hybrids 2 1/2 years old
15 AAA nimh greensleeve 550/650 mah 
18 AA nimh greensleeve 1200mah (generic cell phone battery)
15 AA nimh greensleeve 1500-1600mah

I have tested all but the LSD cells for capacity I retest only when I
have what I consider a weak cell on my BC900 and I pull the weak ones and match them
with other weaker ones or toss them when they are 1/2 or less capacity approx.

I have found my rayovac charger the most easiest forgiving charger able to recharge most without a problem even
jump starting cells refused by my bc900 and charging cells my duracell mobile has errors on with no errors. The 
bc900 will charge most cells but will not start charging them if voltage is too low and you have to sometimes set the
charge rate up to 500mah or higher to get it to terminate well. If charging 4 cells at 1000mah sometimes channel 4 doesn't want to complete as fast I have had to pull cells out of it that were marginal. I don't trust the bc900 with damaged or junk cells.

junk cells are good for lots of things. if you rarely use something or have a low drain device you use on occasion that has no standby drain like a small LED light or LED taplight it replaces alkalines and doesn't tie up expensive LSD cells. I worry none about destroying junk cells and if they will run the things I put them in well enough lower capacity only means more recharging. If I find myself recharging more than once every 4-6 months I start using better rechargeables in them. I have a magnetic message thing on my fridge with a clock that is going on 2 years using generic nimh AAAs in it... some of the batteries may be toast but I only had 33 cents in each of them and have recharged them a dozen times already.

compare $1.50-$3.00 for high end nimh cells with 25 cents to $1.25 for low end nimh cells and start accidentally destroying them and it adds up. I tend to toss nimh when they get below 500mah capacity for AA and 300mah for AAA cells as in most things that requires recharging too often and becomes an anoyance instead of a savings. I have a taplight that averages 50ma over the life of the batteries so can run for about 12 hours off 600mah AAs and at times I accidentally leave it on killing the batteries sometimes reducing capacity some. The cheaper junk batteries can sometimes take a tremendous beating that high end nimh would lose considerable capacity. It is also nice if you have a fast charger you can top off low end junk cells in no time vs 2000/800mah AA/AAA cells which take several hours to *protect* them from losing capacity. I have charged some 1200mah nimh in an energizer 15 minute charger in 5 minutes to top them off.... they got hot and I didn't care and 5 months later I recharged them in my 1 hour rayovac charger in 12 minutes. The advantage of fast worryfree recharging with throwaway nimh cells is a plus. You can also put them in stuff and give them away to someone that has a charger instead of giving them no batteries or disposables vs giving them a high end cell.


----------



## n3eg (Nov 21, 2009)

TakeTheActive said:


> **CRAP*:*
> - meaning their current Capacity is *LESS THAN 80% of their 'Originally Stated Capacity'* (as per *SilverFox*  ).
> .
> *NiCD/NiMH Cells:*
> ...




I never maintain crap cells. Actually, the way things are now, anything that's not a "loop" or a "hybrid" is a crap cell.

Active chargers: BC-900, Cadex 7000 series (at work), 3 Eneloop chargers, and one miscellaneous vehicle charger.

Crap cell inventory: I try to maintain that at zero. Crap NiMH cells will never improve. Deep discharge, repeated cycling, etc. usually fails.
Nicads are a different story, where a battery can sit for years and cycle 5 times back to 100%. NiMH is a use it or lose it situation. When it's gone, it's gone for good.

Maintenance: Recycle bin at 79%. So far, no hybrids or "loops" have made it there. I'm down to 4 Duracell 2500s in the regular category, which are headed there for self-discharge REAL soon now.

Success/failure: When I first got the BC-900, I had some junk Eveready 1800s which got real hot. Also, some Nexcell 1200s from the first days of NiMH melted an old trickle charger at 100 mA. No pictures, since these were my camera batteries. Never had problems with Eneloops/Duraloops/Hybrids/Kodaks - and I trickle charge them all the time.


----------



## brted (Nov 21, 2009)

TakeTheActive said:


> Your (Active *AND* Inactive) CHARGER inventory.
> Your (at least approximate) *CRAP* cell inventory (i.e. Manufacturer / Chemistry / Capacity / Age / Number of cells).
> Your current MAINTENANCE procedure(s).
> Your SUCCESS / FAILURE picture.



I bought a MH-C9000 after reading these forums and it is my primary charger. I also have a Maha C-204F which is a good charger, even though it charges in pairs. I recently got the crazy DX universal one-cell charger, which works with NiMH's so I will count it as active also.

Inactive chargers include two Zeikos AA chargers (I got a Zeikos charger free with my Fenix L2D on eBay this year, and the batteries were crap so I asked for new ones and they sent 4 more crap batteries and another charger). Also an Energizer 1-hour charger and a Digipower charger. I may have thrown away my Rayovac Renewal charger. I also have a second C-204F with only one bay working.

The bulk of my batteries were bought in the last year (Eneloop, Duraloop, and some Rayovac 4.0), so they are not crap. After getting the C9000, I culled some batteries but still have a couple of batteries that are over 60%-80% of their nominal capacity. I have enough newer LSD cells that I won't ever need them though.

Maintenance. They mostly sit in the drawer until I need them. I leave them full, which may not be the best thing, but they are ready immediately. The non-LSD cells I will charge every few months when I remember.

Success/failure? I can live with 60% instead of 80%. 60% of a 2700 mAh battery still isn't that bad.


----------



## Vikas Sontakke (Nov 21, 2009)

I am with Lynx. I have RayoVac 1hr, Sanyo MNO5 and recently purchased Thunder AC6 hobby charger. I have some old Panasonic 1600s and 2100s, many 6-7 year old white Singapore Dynacell from MCM-InOne, Infamous Energizer 2500, some Eneloops and some Duraloops. I have lost majority of the Energizers. Surprisingly, all AA Dynacells are still going strong but I have lost few AAA Dynacells. Both Rayovac and Sanyo refuse to charge them.

I have tried to measure capacity using the hobby charger but I have not mastered it yet.

I still remember how some folks here were warning about the Rayovac 1-hr charger but it is still my go to charger after so many years. It is one of the best one in terms of recognizing a full cell. If I recall correctly, it charges at around 1800mA x 4, faster than most of the newer and fancier chargers and very rarely has missed a termination for me.

I had many older Sanyo NiCd but they have all spewed out their electrolyte.

- Vikas


----------



## Eugene (Nov 22, 2009)

I got rid of all my crap chargers but kept the old crap batteries. Those go in the kids toys, the little race cars or trains that take one AA and you find them underneath furniture weeks after they fully discharged the battery.


----------



## qwertyydude (Nov 22, 2009)

I don't care about capacity, I just re-bin them with similar capacity cells, I only care if they can output a stable current. When they can no longer output at least 1c, in my case 2 amps on a dead short then they go in the trash can.


----------



## MarioJP (Nov 23, 2009)

That's one thing I don't understand? Why is the cell pushing out less and less amps??. I did a similar test with some old cells I used to have, and the amps that the cell pushes out is weak. Whatever happen to pushing tons of current from the cell??

And what causes this strange phenomenon??. That is one thing I can't quite understand why this happens??. Another set i have are quite old but they are lsd duraloops (black top). They lose their charge to the point where its half way but not completely drained in matter of days. I don't even use these cells except in my flashlight because of this problem.

That's why I end up buying brand new duraloops to replace the old ones. But here is the thing those old cells still perform better than any alkaline cell but not good enough like a brand new duraloop. 

Question is toss them or keep them??.


----------



## Lynx_Arc (Nov 23, 2009)

MarioJP said:


> That's one thing I don't understand? Why is the cell pushing out less and less amps??. I did a similar test with some old cells I used to have, and the amps that the cell pushes out is weak. Whatever happen to pushing tons of current from the cell??
> 
> And what causes this strange phenomenon??. That is one thing I can't quite understand why this happens??. Another set i have are quite old but they are lsd duraloops (black top). They lose their charge to the point where its half way but not completely drained in matter of days. I don't even use these cells except in my flashlight because of this problem.
> 
> ...


black top LSD duracells are NOT duraloops (eneloops) but are instead what I call durabrids or rebadged rayovac hybrids. I have had two or three rayovacs I discharged too low and it damaged them to less than half capacity.


----------



## MarioJP (Nov 23, 2009)

Right Durabrids lol. how low did you discharge them?


----------



## Lynx_Arc (Nov 23, 2009)

MarioJP said:


> Right Durabrids lol. how low did you discharge them?



one of them was below half a volt, another I think measured 0v? one was in a lantern and it discharged faster than the other 3 which were still over 1.2v.


----------



## MarioJP (Nov 23, 2009)

Sounds like the weaker cell in you lantern might of went into polarity reversal.


----------



## Lynx_Arc (Nov 23, 2009)

MarioJP said:


> Sounds like the weaker cell in you lantern might of went into polarity reversal.



I don't remember but I think not. I have rarely seen nimh cells go into reversal but have had an alkaline AAA that went backwards 1v.....


----------



## OpenGuy (Nov 25, 2009)

TakeTheActive said:


> Please post:
> 
> Your (Active *AND* Inactive) CHARGER inventory.
> Your (at least approximate) *CRAP* cell inventory (i.e. Manufacturer / Chemistry / Capacity / Age / Number of cells).
> ...


 Active chargers:

Maha MH-C9000
Rayovac PS4 (at work, emergency use)
Sanyo NC-MQH01U (travel charger)

Inactive chargers:

Rayovac PS4 (at home)
Quest CH-1000
Rayovac PS1 (US)
Rayovac PS1 (French)

Active Batteries:

18 Sanyo Eneloop 2000 mAh (where did the other 2 go?)
12 Powerex Imedion 2100 mAh
4 Sanyo 2100 mAh

Inactive, known useful batteries:

4 Sanyo 2700 mAh
4 Powerex 2700 mAh
4 Duracell 2650 mAh
4 Energizer 1850 mAh
4 Rayovac 1600 mAh

Inactive, unknown state batteries:

4 Sanyo 2700 mAh
4 Energizer 1600 mAh
4 Rayovac 1600 mAh

Inactive, known rocks:

4 Sanyo 2700 mAh
2 Lenmar Non-mem pro 2300 mAh (recycled 6 others long ago)


Current maintenance procedures:

Periodic deep discharge (300 mA on MH-C9000, rest, 100 mA on MH-C9000, rest, discharge to between 0.9 and 1.0 volts on slow discharger (battery connected in series with rectifier and 10 ohm resistor), terminal clean, fast charge (1000 mA to 1400 mA depending on capacity), rest, and a few hours of slow charge (using "break-in" mode on MH-C9000 and removing batteries after 2 to 3 hours).

Results:

Doing it once or twice perks them up a bit, but capacities slowly declining.

Newer (non-LSD?) cells will eventually develop rapid self discharge.


----------



## jhellwig (Dec 3, 2009)

qwertyydude said:


> I don't care about capacity, I just re-bin them with similar capacity cells, I only care if they can output a stable current. When they can no longer output at least 1c, in my case 2 amps on a dead short then they go in the trash can.



Is that how you are really testing cells?


----------



## Turbo DV8 (Dec 3, 2009)

> Originally Posted by *qwertyydude*
> 
> 
> _When they can no longer output at least 1c, in my case 2 amps on a dead short then they go in the trash can._


 


jhellwig said:


> Is that how you are really testing cells?


 

"Tough Love."


----------



## LuxLuthor (Dec 13, 2009)

I like Eneloops. :thumbsup:


----------



## paulr (Dec 13, 2009)

Life is too short for crap. I recycled a bunch of crap cells but find I still have a few. If you want 'em enough to send a few bucks for postage, PM me.


----------



## s0lar (Jun 13, 2010)

Since I have made a MAX712 based charger as part of a school project, I am checking this forum a lot.
I trew away 20 cells and still have 50 left or so.
Most of them are neglected, some are new and in better shape.
Some suffer from voltage deprevation, how can I best cure them? 
One is a sanyo 2300.
I have done 5 cycles at 700mA charge and 300 to 1000mA discharge.
It starts out at 0.92-0.95V and climbs up to 1.0-1.1V after 15-45min. I still get 1700mA out of it in the end but I don't trust the cell if used as part of a pair.


----------



## TakeTheActive (Jun 13, 2010)

s0lar said:


> Since *I have made a MAX712 based charger as part of a school project*...


You mentioned your school project a few times - if you haven't already, please post an overview (or a LINK). 



s0lar said:


> ...*I am checking this forum a lot*...


I noticed that you've been going through the Archives. As one who personally spent SEVERAL hours per day for SEVERAL MONTHS doing just that, I commend you for '*Hours Well Spent*'. :twothumbs



s0lar said:


> ...*I trew away 20 cells* and still have 50 left or so.
> Most of them are neglected, some are new and in better shape.
> Some suffer from voltage deprevation, *how can I best cure them?*...


Since you have a 'Maha MH-C900 _clone_' (which I looked up, posted LINKs about and was _chastised_' for going OT here: *Duracell 2650mAh NiMH, test result* :shakehead ), the information in Post #2 above and in my Sig Line LINKs regarding *Impedance Check Voltage* and *Deep Discharge* is where you should begin.

Too bad you already *RECYCLED*  20 cells - it would have been interesting to know their ICV's and CAPACITY.



s0lar said:


> ...One is a sanyo 2300.
> *I have done 5 cycles at 700mA charge and 300 to 1000mA discharge*...


IME, *Deep Discharges* and *Forming Charges* yield better results from *CRAP* cells than repeated CYCLES.








s0lar said:


> ...
> *It starts out at 0.92-0.95V and climbs up to 1.0-1.1V after 15-45min.* I still get 1700mA out of it in the end but I don't trust the cell if used as part of a pair.


You also touched upon this idea 2 days ago:


s0lar said:


> ...*Would it be possible that the cell reaches the termination point (1.47V) faster and faster as it has undergone cycles?... ...As the cell ages, it sure is possible that it reacts different to a charging current, making it increase its voltage faster*...


and from my 'Non-Engineer / Non-Scientist' point-of-view, I attribute the faster voltage rise to 'Spent Chemicals' and/or 'Large Crystals' (blocking access to potentially useful chemicals). For #1, you're SOL; but for #2, you can 'Experiment'.



s0lar said:


> ...*I would like to do these test again with a different charger, one that does not terminate at 1.47V*.
> I would discharge in the maha after 1h rest.


If the cells are HOT (~120°F) when your PRO 1 Geniux (C9000) terminates @ 1.47VDC, I personally wouldn't switch to another charger with a higher MAX VOLTAGE - you'd only COOK the cells further. I would investigate their *Internal Resistance* (there are MANY methods posted) and see if *Deep Discharges* and *Forming Charges* have any effect. :thinking:


----------



## s0lar (Jun 14, 2010)

I still have some of the cells ready to be trown away, so I will check the Impedance with my charger. The bag with crap is still sitting at home.
I find 0.1C forming charges so slow, so that's the last thing I wanna try. I will create a topic with my project later today.
Thanks for the answers.


----------



## s0lar (Jun 14, 2010)

I just tried 3 crappy cells.
One Top Craft 2300mA gave 1.58, I trew it away because my other charger missed termination a couple of times with that cell.
Then 2 sanyo 2300.
In one I still believe.
It gave 2.68, the other gave 2.71 before both going to high a second or 2 later.
I charge them with my dumb charger and will test further after deep discharges.


----------



## Lilien (Jun 14, 2010)

I voted with "YES", because I used over months some AAA cells in my 
mouse, that were rejected by my MAHA C-9000 charger (>2,5V "HIGH"),
but otherwise still worked fine. Actually I had to keep my old crappy
charger to be able to still charge these "crap" cells. 
I just bought an new mouse (1xAA), so maybe it's time to say goodbye. 

Regards, Juergen


----------



## TakeTheActive (Jun 14, 2010)

s0lar said:


> I just tried 3 crappy cells.
> *One Top Craft 2300mA gave 1.58*, I trew it away because *my other charger missed termination* a couple of times with that cell...


An ICV of 1.58VDC is a nice, low number - typical of VIBRANT cells. What's its measured CAPACITY? A 100mA DISCHARGE followed by a *LT 2300mAh* (I'd start with 1800mAh) BREAK-IN (or 2 or 3) might 'perk it up'. What's the MAKE & MODEL of the 'other' charger?



s0lar said:


> Then 2 sanyo 2300.
> In one I still believe.
> *It gave 2.68, the other gave 2.71* before both going to high a second or 2 later.
> I charge them with my dumb charger and will test further after deep discharges.


Those 2 are pretty deep into HIGH territory (over ~2.10VDC)  . I have a few DUMB 140mA and 150mA series (2 cells per channel) AAA/AA chargers that I use for cells like that. Also, my TIMED Sears DieHard 7-Hour Charger switches to 45mA/80mA/100mA/100mA for AAA/AA/C/D after 7 hours so if I don't unplug it, I can utilize those low Charge Rates too. What's the mA of YOUR DUMB charger? 

"High Capacity / non-LSD / Neglected" could mean separator damage. But, if their Self-Discharge isn't too bad, they could still deliver plenty of their Capacity in clocks, thermometers, remotes, etc...


----------



## Battery Guy (Jun 14, 2010)

I love testing, comparing performance, abusing, misusing and otherwise getting as much data as possible out of batteries....

BUT...

This testing takes a lot of time to do right, so when I do it I use good cells that have a known history. Using "crap" cells would just be a waste of time. Just like they taught you in computer programming class: garbage in equals garbage out. (Ok, give me a break...the last computer programming class I took was FORTRAN).

Anyway, life is too short and I am too busy to be messing around with crappy old batteries. 

Cheers,
Battery Guy


----------



## s0lar (Jun 15, 2010)

My dumb charger is a GP Powerbank 4, charge rate is 180mA for AA and 80mA for AAA.
Other chargers:
Memorex MRX4000: smart (-dV, max V, T and timer), 700mA AA, 350mA AAA.
Top Craft TCU-810 (no info available anywhere...): smart (-dV, max T, charges only per pair in series and 9V!), 800mA AA, 300mA AAA, 13mA 9V.
Memorex Pro 1 Geniux (MAHA 9000)
Just bought:GP 30min U-Smart: smart (-dV, timer, very picky!), 3400mA AA and 1700mA AAA and that's effective charge, I tested!
now recently a BC 700 also to do more discharge tests at the same time and charge my lower capacity AA and all AAA cells.
The GP 30min came with 2500 cells but one missed termination is 2nd charge...
It was still a good deal, I paid $20 for the charger and 4 2500 cells.


----------



## WDG (Jun 15, 2010)

*OT: FORTRAN*



Battery Guy said:


> (Ok, give me a break...the last computer programming class I took was FORTRAN)



Heh! I took FORTRAN in '79 (was that 1979, or 1879? I forget...) IIRC, I failed. Fortunately, that means it's not floating around in my head taking up valuable space!  All I really remember is doing flow-charts and those contemptible stacks of cards.


----------



## unattended (Jan 22, 2012)

[*]Your (Active *AND* Inactive) CHARGER inventory. 

inactive: some dumb to very dumb chargers that came with bad to very bad cells 

mostly inactive: accu manager 10 which i suspect to be a (speak french) accu manger ; ) 

active: mec av4m (which is only little behind the maha c9000) and the 99% perfect pulsar 2+ hobby charger + waiting for the intellicharge i4 (i´m in a 230v country : ) 


[*]Your (at least approximate) *CRAP* cell inventory (i.e. Manufacturer / Chemistry / Capacity / Age / Number of cells). 

accupower aa nimh 2900mah - 4x - will hold down to 800mah ! : / 

activ energy (aldi) aaa + aa nimh ??? + 2300mah - maybe 4 each 

minwa aa nimh 2200mah - 4x (i think those came with one very dumb charger) 

tronic (lidl) aa nimh 2500mah - 8x 

[*]Your current MAINTENANCE procedure(s). 

cycle cycle cycle 
now after reading about it here i will try to deep-discharge those ugliest cells 

[*]Your SUCCESS / FAILURE picture. 

cycling with the av4m brought some 20% cells back to 80 %


----------



## MidnightDistortions (Nov 2, 2014)

Active
La Crosse BC-1000 (current/main use charger for all NiMhs/NiCad cells)
4AA/2AA Duracell CEF14N (use as backup, crap cells only)
4AA/AAA Energizer charger (emergency charger, crap cells only)

Inactive/Dead Chargers
Eveready NiCad Charger
2 Rayovac NiMH Chargers

AA's around 1000mAh (or higher) usable capacity (best batteries are on top)
4 2600mAh LaCrosse (2014)
4 2300mAh Duracells (2005)
3 1800mAh Duracells (2005)
4 2500mAh Energizer (2005)

2AA Eveready NiCad (1997 or earlier?) (200-300mAh capacity)
3AA Rayovac NiMHs (1999) (no to very little mAh capacity only works in remotes or clocks)

4AAA La Crosse (2014)
7AAA Energizers (2006)
4AAA from a Cobra walkie (2007) (360mAh average capacity)

I had no idea the Duracells were sort of bad until i cycled them in a charger and tried using them in a USB charger for cellphones, though they work just fine in flashlights, portable cd players and radios that take AA batteries. The LaCrosse batteries were just terrible from the start and had them overheat a few times in the charger on negative side of the terminal (they might have been severely overdischarged). I was shocked that the Rayovacs even hold a charge but doesn't give out much mA. Usually i'll just continually topping these batteries off, the Duracells maintain their charge for longer than any of the others (up to 3 months!) so they don't require charging as much unless i drain them. The Energizers require charging frequently (the self discharge is really high), but they perform decent enough to be put in a flashlight after being left on the charger, trickle charging for a day. I didn't add the AAA's i got with the LaCrosse charger only because i never ran capacity tests on them but they performed fairly well for AAA's in the USB charger. The Rayovac and Eveready are good enough for tv remotes. I haven't needed to recycle rechargeables yet but if any of these batteries start requiring a charge every few hours or start expanding or something to that effect i'm going to permanently retire those batteries.


----------



## InHisName (Nov 5, 2014)

I got an Opus BT-C3100 that does amazingly better than any other of my chargers in refilling my crap cells.

Now I have 3 categories for junk cells:
1. Junk: Fails C9000 to HIGH ( > 2.12 )
2. Junk squared: Fails C9000 reboot (>2.86 approx)
3. Junk cubed: wont charge in any charger but the Opus
The most useful purposes for Junk cubed is recycling and educational experimental charging. Not good enough for even remotes.


----------



## SaraAB87 (Nov 8, 2014)

The cost of rechargables is low these days when bought on sale so all of my crap cells have gone to the recycling bin as I replaced them with batteries that were bought on sale at $6-8 a pack for duraloops or ray o vac's LSD cells. Struggling with crap cells is not fun and is a time waster. If a cell is crap it will die within 2- 3 months even in a remote from self discharge, then the remote doesn't work so every 2-3 months you have to change and charge the batteries. Meanwhile most LSD cells will last 1-2 years or possibly more in a remote (at least in the one remote I use for my tv) without needing to be touched which is awesome., especially if you have multiple remotes.


----------



## MidnightDistortions (Nov 11, 2014)

MidnightDistortions said:


> 3AA Rayovac NiMHs (1999) (no to very little mAh capacity only works in remotes or clocks)



I might have jinxed these batteries, one of them won't hold a charge or recharge.. trying the dumb charger but may have to retire one or more of these batteries for good, they are a bit shorter than regular batteries so it may have been inevitable that these batteries would finally give out. 14-15 years though from these isn't bad though it might have been shorter or longer since they have been in storage for 5-7 years.


----------



## WalkIntoTheLight (Nov 11, 2014)

SaraAB87 said:


> The cost of rechargables is low these days when bought on sale so all of my crap cells have gone to the recycling bin as I replaced them with batteries that were bought on sale at $6-8 a pack for duraloops or ray o vac's LSD cells. Struggling with crap cells is not fun and is a time waster. If a cell is crap it will die within 2- 3 months even in a remote from self discharge, then the remote doesn't work so every 2-3 months you have to change and charge the batteries. Meanwhile most LSD cells will last 1-2 years or possibly more in a remote (at least in the one remote I use for my tv) without needing to be touched which is awesome., especially if you have multiple remotes.



You're right, from a practical viewpoint. But some (like me) like to mess around with batteries as a hobby. I like to see how long I can keep old batteries going. I still use some 14 year old NiMH cells, and they are still useful in low-drain applications like garden lights or dim indoor LED lights. The may only put out a lumen of light, but the cells will power them for a few days. For outdoor lights, they get recharged by the sun, so I don't have to charge them up myself.

Could I replace them with some Eneloops? Sure. But, why do that, when they work well in the application I use them?


----------



## MidnightDistortions (Nov 11, 2014)

SaraAB87 said:


> The cost of rechargables is low these days when bought on sale so all of my crap cells have gone to the recycling bin as I replaced them with batteries that were bought on sale at $6-8 a pack for duraloops or ray o vac's LSD cells. Struggling with crap cells is not fun and is a time waster. If a cell is crap it will die within 2- 3 months even in a remote from self discharge, then the remote doesn't work so every 2-3 months you have to change and charge the batteries. Meanwhile most LSD cells will last 1-2 years or possibly more in a remote (at least in the one remote I use for my tv) without needing to be touched which is awesome., especially if you have multiple remotes.





WalkIntoTheLight said:


> You're right, from a practical viewpoint. But some (like me) like to mess around with batteries as a hobby. I like to see how long I can keep old batteries going. I still use some 14 year old NiMH cells, and they are still useful in low-drain applications like garden lights or dim indoor LED lights. The may only put out a lumen of light, but the cells will power them for a few days. For outdoor lights, they get recharged by the sun, so I don't have to charge them up myself.
> 
> Could I replace them with some Eneloops? Sure. But, why do that, when they work well in the application I use them?




I regularly have to recharge my Energizers in a flashlight i use daily, i for sure could just toss them for some Eneloops. It would make more sense to use batteries with longer capacities but for me it takes just a few minutes to take the batteries out and hook them up to a charger. It wouldn't make much sense to put batteries that have less than 40% charge in a device with some presets that reset every time the battery goes dead but tv remotes or flashlights are easy to recharge. I think it differs from every person and from an economical standpoint if the batteries function in a device for a day then that's good enough for me, besides saving money on single use batteries the whole point i use rechargeables is so it reduces waste. Whatever alkalines i have left or that i get from new devices i get whatever energy is left in them. I like to get whatever recharges i can out of a battery before they no longer work in any device.

In solar lights, old batteries are perfect for that application as they don't take much energy to operate. If the device didn't work as intended there is no point in using the crap batteries. Then again i am used to the regular need of recharging HSD NiMHs and ever since 2004 i stopped buying alkalines all together. While they may have lasted a long time in remotes they did tend to leak which is why i much preferred having to recharge NiMH batteries every several months or actually i shared the batteries among my devices at that point.


----------



## Kurt_Woloch (Nov 12, 2014)

My (Active *AND* Inactive) CHARGER inventory:

Active chargers:
TRONIC TLG 500 B1 (bought at 9 EUR at Lidl)
Atari 2600 power supply (+ cord and plug contraption)
Built-in charging electronics of three electric shavers and one electric toothbrush containing NiMh batteries
Lytron 522 (only for attempting to bring up 0V cells)

Inactive chargers:
hama 46523 (sometimes used for attempting to bring up 0V cells)
TRONIC TLG 1000 B2
Robbe Netzlader 3 (only inactive for NiMh charging, but still being used for Lead-Acid batteries)
Base station of MEGACALL cordless telephone (gave up the landline)
MW MW398 (broken)

Crap Cell Inventory (sorted by age):
Robbe NiCd 1400 mAh 7.2V racing pack (6x Sub-C) from 1987 (1x)
JEWO NiCd 1800 mAh C cells from 1988 (4x)
Jewo NiCd 100 mAh 9V block from 1989 (1x)
Lytron NiCd 850 mAh AA cell from, I think, around 1990 (1x)
Ucar NiCd 110 mAh 9V block from 1993 (1x)
Practa NiCd 4000 mAh D cells from 1998 (2x)
Uniross NiMh 1500 mAh AA cells from, I think, 1999 (4x)
Nytech NiMh 2000 mAh AA cells from 2002 (4x)
GP Industrial NiMh 600 MAh AAA cells from 2007 (3x) (came with cordless phone)
Sanyo Eneloop NiMh 800 mAh AAA cells from 2010 (3x)
H+H NiMh 4000 mAh C cell from 2011 (1x)

Maintenance procedure (for both Crap and Non-Crap cells):
There's an activity scheduled in my calendar called "Recharging of non-used cells" coming up every 2-4 months depending how busy I am with other things. On each of these events, I will measure the voltage of all cells which are currently not inserted into any device and not shrink-wrapped and recharge the cells measuring belov 1.25 V using the Tronic TLG 500 B1. Cells reading 0V which are rejected by the Tronic will be put into the Lytron 522 in an attempt to bring them up to a level where the Tronic will accept them. If they stay at 0V, they will be recycled.
At this event, I will also check all the single-use and lead-acid batteries currently not inserted anywhere (and one of the lead-acids that is inserted) with slightly amended procedures.
The non-active shavers will be plugged in for charging anyway since I can't check the voltage there. The racing packs will be recharged if reading below 7.5 V using the Atari 2600 power supply contraption.

Success / Failure picture:
I think that before 2010 I didn't know how to properly take care of NiCd and NiMh batteries. Then I learned it's important to never let them run completely down in order to improve their cycle life (although many manufaturers of devices with built-in NiMh batteries say you should let the device run down before recharging it) and not to "cook" them by overcharging (at a charging rate of 0.1 C, they are full when they get warm or hot). Although I regularly have to recycle one or two cells on each event, it's seldom that cells get delegated to the "crap" pile. This happens if a new device comes into service and I need batteries for it, checking all I have if they might be up to the task, or if severe troubles occur, like batteries that are supposed to be fully charged not being able to power a device I insert them into or immediately showing "Low". I think I do take proper care of them now. The Tronic TLG 500 B1, although having been very cheap, has four slots, discharges batteries for a while before recharging them (but without letting them run completely down) and (most of the time) stops charging when they are full (or after eight hours, whichever comes first). I think more isn't worthwile with the prices of new AA, C and 9V NiMh batteries when they are on sale. I even doubt if it makes sense to do these charging events at all... maybe it would be better to just let the batteries not in use detoriate and buy new ones if I need more than I have and find that I can't revive my old ones.


----------



## WDG (Nov 12, 2014)

All of my 2007 Eneloops went high-resistance a few years ago (all my 2008 Eneloops are still going strong.) They still charge fine in the old C.Crane chargers, and work great in lower draw devices, like clocks, low-powered flashlights, and even old transistor radios. 

I could certainly replace them, but just can't bring myself to dump them while they're still useful. They're not really any additional work to maintain, as my habit is to swap & charge cells in regularly used devices on a weekly basis. The only real difference is they have to go in a different charger. If need be, I still have some "dumb" chargers around for when the C.Crane rejects them. So long as they keep working, I'll let them.

FWIW, I mark them around the top with a red marker, so they don't get mixed with good cells.


----------



## MidnightDistortions (Dec 1, 2014)

I got some interesting results from my 1999 Rayovac NiMH batteries. First off, i barely got much more than 15mAh out of one of them from doing a discharge in this remote i got set up. I discharged them until they were basically under 0.1volt and managed to get 15mAh from that. Did it again a second time and the battery got weak and lost the mAh. So it's definitely not a good idea to repeat fully discharge extremely old NiMHs that do not carry much or any mA. The interesting thing is that battery reaches 1.5 volts on recharging. The other ones don't reach that so im going to discharge the other 2 in the remote, recharge them to full and test them for capacity. Im going to try only discharging them to 0.9volts which is the safer course of action and see with a few refreshes whether they can retain mA.


----------



## SaraAB87 (Dec 2, 2014)

I have finally decided to recycle my Duracell 2650's as they are quickly losing capacity and will eventually die, crap cells anyways is what most people say about them. Oh well I got them for free so I don't care.


----------



## MidnightDistortions (Dec 4, 2014)

One of my 2300 Duracell batteries went high resistance and is showing 20-30% capacity and can't be used in any of my flashlights. Threw it in a weather radio clock along with the other 2300 Duracells. The Rayovac cells does not show any capacity but works fine in tv remotes. My 2500 Energizers continue to degrade but amazingly still shows over 950mAh in capacity so it runs fine in a daily use flashlight i carry around the house, pretty soon though they will be used as backup tv remote batteries or PC mouse.


----------



## MidnightDistortions (Jan 17, 2015)

It's interesting to note that my 2500mAh Energizer cells actually* jumped in capacity*!! Some of them as high as a 10% increase. I have played around with crap NiMH cells to notice they don't really regain capacity over time but these cells did and not just one but all 4 cells did this. I kinda experimented with this because it seems they only degrade if they are not slightly overcharged into my Duracell CEF14N charger. It could only stand to reason that the Energizers suffer from high resistance and will not fully charge in the La Crosse (BC1000) charger.

I wonder if WalkIntoTheLight can confirm, this since WITL is the only user on here that plays around and uses crap cells. I won't hold my breath though that these batteries are getting better, they still self discharge within several days so i generally will recharge them every other day to just put back what charge was lost. It might also be the reason for the jump in capacity.


----------



## MidnightDistortions (Sep 15, 2015)

MidnightDistortions said:


> Active
> La Crosse BC-1000 (current/main use charger for all NiMhs/NiCad cells)
> 4AA/2AA Duracell CEF14N (use as backup, crap cells only)
> 4AA/AAA Energizer charger (emergency charger, crap cells only)
> ...



Wanted to give an update on my crap cells. Most of them seem to be doing fairly well, The 2500mAh Energizers won't hold a charge for long and they are close to being the Rayovac cells. The Nicads no longer hold much of any capacity and a few of the Energizers are showing HIGH in my C9000 charger. A few of my Duracells went bad and they self discharge too quickly. With using the remaining power in my alkalines in this pest device that originally needed a 9V but i hooked up an 8 battery pack up to it and it has been running quite well (well with some older alkalines leaking all over, but it's not surprising). The Rayovacs do quite well in clocks, at least the digital ones. Tried using an analog one but there's really no milliamps in those cells so about the only thing they can power is remotes or digital clocks. They will be replacing the alkalines in any clocks that i have currently along with the duracells that are going bad. The 2500mAh Energizers i will experiment in clocks to see how well they function. Some of the crap cells have gone in a LED strip and they have been fairing quite well so long as i keep an eye on the voltages so none of the cells reverse charge and they'll most likely end up like the Energizer AAs. 

Trying to hold onto the AAA cells longer than the AA's since i had already bought AA cells in 2013-2014 and want to wait before getting a 12 pack of Eneloops. I do have an 8 pack of Eneloop Pro AAA cells and a set of AAA radioshack cells so those cells will tide over if the AAA cells decide to die out. Already the Energizers and even La Crosse batteries won't function well in this laser pointer without topping the cells off, give it a week or so and the laser will dim out, not the case though with LSD cells but i'm going to try to hold out until 2017-2019 for some regular AAA Eneloops to try to space out the lifespan of the cells.


----------

