Best way to maintenence Eneloops?

[Danne71]

Hello, i´m from Sweden and this is my first post on this exellent forum.

I have a lot of Eneloops and i wonder what is the best way of taking care of them. I use them in all my equipment from remotes to gps´s.

When i bought them 2 years ago i did a break in on all of them on my c-9000 and they all had 1920-1950 Mah. Since then i have just charged them and used them.

Last night i ran a Charge/Discharge (1000Ma. charge+topoff/400 Ma. discharge)on them and they had "degraded" to 1820-1850 Mah. I know this isnt mutch but its a little sign of poorer performance. I tried two R/A on them but it didn´t improve the performance.

So my question is:
Should i do another break in on the batteries or should i wait for the batteries to get even lower performance. I´m afraid that i might stress the batteries if i do a break in just after 7 charges (even if they are two years old i have just charged them around 7 times). The manual says its recommended to do a break in every 30 charges.

Is it healthy to do a break in just after a small sign of degraded performance, or is it healthier to save the break in´s to when the batteries reach like 1650-1700 Mah?

 

[Niconical]

They may have only done 7 charges, but if that was over 2 years they spent quite a lot of time doing nothing at all.
Put them through the break-in again, it will do them good

EDIT: Just thought I should clarify. That time spent doing nothing over the 2 years is exactly the reason for the break-in. Although the eneloops will of course still work after 1 year (or even 2), inactivity does build resistance, hence the break-in will help.

 

[Black Rose]

As Nic said, do a break-in cycle on them and it should restore their performance.

I've got a bunch I need to give a break-in, or at least a couple cycle mode runs. I need a second C9000

 

[Danne71]

Thanks!!

I have them on break in right now.

 

[Danne71]

I was thinking.....

Because i don´t charge my batteries too often, i could use the break-in mode every time i charge them. I could use a timer so it don´t discharges after 16 hours.

I have read that Tom (SilverFox) thinks this is the gentliest way to charge your batteries. According to him you allways get the fulliest charge this way and the longest cycle life too.

I shure got the time to charge my batteries this way.

Mabey SilverFox could anwer this question to me???

Sorry for my english!!!!!!

 

[TakeTheActive]

...I have a lot of Eneloops and i wonder what is the best way of taking care of them. I use them in all my equipment from remotes to gps´s...

Do you 'Assign' a battery to a specific device or do you randomly move them around? AFAICT, 'Device Discharge Current' directly affects HOW you want to maintain the battery, ESPECIALLY if it's getting INFREQUENT charges.

...When i bought them 2 years ago i did a break in on all of them on my c-9000 and they all had 1920-1950 Mah. Since then i have just charged them and used them...

For 'Daily Use' batteries, 'Charge-and-Go' with the occasional 'Break-In' and/or 3-5 'Refresh-and-Analyze' cycles works fine. For 'Low Discharge Current / Infrequent Usage / Storage Box Queens', special care is required.

...Last night i ran a Charge/Discharge (1000Ma. charge+topoff/400 Ma. discharge)on them and they had "degraded" to 1820-1850 Mah. I know this isnt mutch but its a little sign of poorer performance. I tried two R/A on them but it didn´t improve the performance...

ONE / TWO 'Refresh-and-Analyze' cycles?!? How about trying a 'Break-In', then 3-5 R&As.

...So my question is:
Should i do another break in on the batteries or should i wait for the batteries to get even lower performance. I´m afraid that i might stress the batteries if i do a break in just after 7 charges (even if they are two years old i have just charged them around 7 times). The manual says its recommended to do a break in every 30 charges.

Is it healthy to do a break in just after a small sign of degraded performance, or is it healthier to save the break in´s to when the batteries reach like 1650-1700 Mah?

Rechargeable batteries are like the muscles in your body - USE 'EM OR LOSE 'EM!

And your batteries are atrophying! :sick2:

CLICK on my Sig Line LINK and read the articles in the 'Rechargeable Battery' section. Bottom-line is you have a bunch of NEGLECTED 'Storage Box Queens'. If you want VIBRANT cells, you need to USE THEM. If you don't have enough devices that are using them, CYCLE THEM.

If you figure on a 10-year lifespan with ~500 cycles, that's roughly one recharge per week. With seven recharges in two years, what are you saving them up for? 35 recharges in 10 years and they're DEAD ANYWAY! Plus, at a MUCH REDUCED average capacity.

My Opinion:

You can either assign each cell to a device and maintain it according to the device's current draw.

*OR*

You can enforce a STRICTER (i.e. Quarterly) '3-5 R&A Cycles' and/or 'Break-In' routine for EACH cell so that ANY cell you choose will be equally VIBRANT.

NOTE: Excessive use of the term 'VIBRANT' due to SilverFox influence! :tinfoil:

[This post can go 'on-and-on-and-on' so please invest a few hours reading the LINKs I've assembled and THEN come back with any further questions. ]

 

[Yoda4561]

I usually use the c9000's default charge as needed, and a discharge+break-in cycle every 6 months or so for good measure on all of them.

 

[Danne71]

What is the point of buying lsd batteries if you cant store them? I thougt charging them every 3-4 month made them vital. Sanyo says it holds 85 procent after one year. They should have put a warning that storing a eneloop this long could harm the batteries. Is there any evidence that storing a eneloop for a couple of months is not good for them? I mean they havent been on the market long enough for this to be tested.

 

[Yoda4561]

It doesn't harm them, but you're only going to get 90% performance out of them instead of 100% after a couple years. It's fine if you just do the discharge-breakin every few years, they'll pick right back up. Some folks just like to keep things in top condition.

 

[SilverFox]

Hello Danne,

Welcome to CPF.

Normal NiMh cells should be kept working in order to stay in very good shape. When you don't use them, they gradually oxidize from the inside and loose capacity.

With normal NiMh cells, you would store them discharged, and run a charge/discharge cycle on them every 30 days. This keeps the cells vibrant.

With cells that are in constant use resulting in several charge/discharge cycles every week, it is recommended to do the 16 hour 0.1C charge every 20 - 30 cycles. With cells that are in storage that you are doing monthly charge/discharge cycles on, it is recommended to do the 16 hour 0.1C charge yearly.

With the introduction of the low self discharge NiMh cells, we are still trying to figure out the best way to care for them. I just put some AAA Eneloop cells into service, and they had been stored with no attention since 2006. I did a discharge, then ran the Break-In cycle in the C9000. They are doing just fine. I don't have a lot of spare cells, but I am tending to ignore my Eneloop cells. I make sure there is some charge on them, then let them sit until they are needed.

While you are seeing some degradation in capacity with your cells, they still are at around 95% of their initial capacity. I would just continue to use them until the capacity dropped to below 90% of their initial capacity. Then you can do another Break-In cycle on them.

With that said, if there are no time constraints feel free to use the Break-In charge portion as your normal charge. You don't have to go through the whole charge/discharge/charge cycle, but can set a timer and stop the process after the initial charge. There is no problems with going through the whole cycle, it just takes a little more time. When you go through the whole cycle, you do get numbers for comparison so you will have to decide if those numbers are important enough to spend the additional time running the whole cycle.

Tom

 

[hotlight]

quick question:

is the "break in" on the Maha c9000, the same as "Refresh" on the BC-900?

 

[Black Rose]

No it isn't.

The C9000 doesn't really have an equivelent of the BC900 Refresh mode.
The closest would be Cycle mode.

 

[Danne71]

Ok. I think i was wrong to begin with. My numbers in the first post was after a regular charge at 1000 mah. After i did a Break-in they come in at 1900-1950 Mah. So i think my cells are completely healty.

Thanks to everyone for helping me!!!!!!!!!!!

 

[thedeske]

This looks like a great place to post a question rather than start a new thread.

I have a Maha 9000 and 20 Eneloop AA on the way.
16 will be dedicated to an 8 cell light I plan to buy soon and the others are backup to to 8 cells I have in use.

The break-in routine looks like 1 day per 4, so I have 7 or so days of break-in ahead at a casual pace for the 28. Any reason not to prep the entire 28?

Half the cells will sit in a drawer as backup. The lights get the most use, but AAs in the shop cycle every 6 months or so (5-7 cells in a large clock, laser level, digital fence)

I'm guessing the El Cheapo Eneloop 2 channel (NC-MQN06U) that came with the first 8 is keepable as a backup. Doesn't take up much space in the drawer.

 

[Mr Happy]

The most important reason to run a break-in cycle on eneloops is for high drain, high power uses. For low drain uses it is not likely to make much observable difference to performance.

 

[thedeske]

The most important reason to run a break-in cycle on eneloops is for high drain, high power uses. For low drain uses it is not likely to make much observable difference to performance.

thanks

 

[travelinman]

It sounds like people are collecting cells and have waay too many. Our use of NiMH cells shows exactly what has been discussed here. Have just enough that you can use them regularily. Any "extras" that you have, give them away to people that can use them regularily.

Like taketheactive says "use em or lose em".

Hot light, the refresh cycle on the BC 900/700 actually tests each cell by charging it up, then discharging and noting the capacity, then it does it again and compares the capacity with the last cycle. It continues these cycles until it see no further gain in capacity. It's a great way to refresh your cells.

I use it all the time and rarely use more than 200 ma charge (the default). I have the time, its a perfectly safe machine, just set it up and let it run. Go have fun while it's taking care of business.

 

[TakeTheActive]

SLOW Charge Rate Is Not Always BEST Charge Rate!

...the refresh cycle on the BC 900/700 actually tests each cell by charging it up, then discharging and noting the capacity, then it does it again and compares the capacity with the last cycle. It continues these cycles until it see no further gain in capacity. It's a great way to refresh your cells.

I use it all the time and rarely use more than 200 ma charge (the default). I have the time, its a perfectly safe machine, just set it up and let it run...

Don't be lulled into the false security that 200mA is always 'safe' and/or 'best'. As cells age, they need more current to insure a positive -DeltaV termination but not too much current to cause excessive heating due to rising internal resistance.

Try this experiment, ESPECIALLY on older cells (skip Step#4 on AAA cells). Instead of REFRESH, or TEST (which only display Discharge capacity):

1. Do a DISCHARGE @ 200/100 and note the final 'Accumulated Capacity'.
2. Do a DISCHARGE @ 500/250 and note the final 'Accumulated Capacity'.
3. Do a DISCHARGE @ 700/350 and note the final 'Accumulated Capacity'.
4. Do a DISCHARGE @ 1000/500 and note the final 'Accumulated Capacity' (watch for overheating).

Compare the results. If the result from #1 is way higher than the others, it missed -DeltaV termination and overcharged (usually without overheating).

Here are some examples. The missed -DeltaV terminations are obvious.

Note, I preceed the recorded capacity with a '+' to denote 'Accumulated Capacity' (Charge IN) vs 'Available Capacity' (Discharge OUT):

Sears DieHard 1300mAh AA NiMH    |   #1    #2    #3    #4
---------------------------------+---------------------------
06/30/09 C9000 Cycle3:   600/ 100|  979   974  1099   960 mAh
06/xx/09 C9000 Cycle2:   600/ 100|  981   992  1104   969 mAh
06/xx/09 C9000 Cycle1:   600/ 100|  970   988  1112   957 mAh
06/27/09 C9000 Discharge:  300   |    0    13    44    15 mAh
06/27/09 C9000 Impedance Check:  | 1.74  1.78  1.59  1.75 VDC
06/16/09 BC900 Discharge:  350   |+1204 +1289 +1234 +1180 mAh
06/15/09 BC900 Test:  200/ 100   | 1100  1061  1165  1120 mAh
06/15/09 BC900 Discharge:  350   |+1212 +1153 +1260 +1156 mAh
06/14/09 BC900 Discharge:  250   |+1243 +1176 +1264 +1172 mAh
06/14/09 BC900 Discharge:  100   |+1722 +1384 +2130 +3380 mAh
04/06/09 BC900 Charge:  700      |+1112  +994   n/a   n/a mAh 
02/26/09 C9000 Impedance Check:  | 1.73  1.79   n/a   n/a VDC
02/25/09 C9000 Break-In          |  932   888   n/a   n/a mAh#
02/20/09 C9000 Impedance Check:  | 1.79  1.89   n/a   n/a VDC
02/19/09 BC900 Refresh:  200/ 100| 1074   990   n/a   n/a mAh
02/07/09 BC900 Refresh:  700/ 350| 1130   952   n/a   n/a mAh
02/06/09 BC900 Charge: 1000      | +322  +241   n/a   n/a mAh
[Bought: 12/dd/00; Datecode: 05 00; ?? Storage ??; Icom; Thermometers]
[06/13/09-#3&4 found @ 0VDC in hand-fan w/switch ON!]

RadioShack 1300mAh AA NiMH       |   #5    #6    #7    #8
---------------------------------+---------------------------
07/03/09 C9000 Cycle3:   600/ 100| 1037   953   979   692 mAh
07/xx/09 C9000 Cycle2:   600/ 100| 1047  1008   987   747 mAh
07/xx/09 C9000 Cycle1:   600/ 100| 1053  1059   979   740 mAh
06/30/09 C9000 Impedance Check:  | 1.81  1.76  1.85  1.98 VDC
06/27/09 C9000 Discharge:  300   |  887   912   894   694 mAh
06/26/09 BC900 Refresh2: 500/ 250|  n/a   n/a  1070   967 mAh
06/25/09 BC900 Refresh1: 500/ 250| 1231  1205   984   769 mAh
06/24/09 BC900 Test:  500/ 250   | 1250  1263  1170  1102 mAh
06/23/09 BC900 Discharge:  250   |+1391 +1387 +1289 +1374 mAh
06/22/09 BC900 Discharge:  100   |+1716 +2150 +1385 +1135 mAh
06/21/09 BC900 Charge:  200      | +219  +149  +731 +2460 mAh
06/21/09 C9000 Impedance Check:  | 0.03  0.14  1.78  0.15 VDC
01/30/09 C9000 Break-In          | 1083  1082  1056  1006 mAh#
01/28/09 C9000 Discharge:  200   | 1014  1019  1012  1001 mAh
01/28/09 C9000 Charge: 1300      |  ---   ---   ---   --- mAh
01/28/09 C9000 Discharge:  200   |    0     0     0     0 mAh
[Bought: mm/dd/yy; Icom Transceiver]
--- Results not recorded

NiMh Rayovac       AA 1600ma  1: 05/11/09 -+1548mAh (Discharge BC-900  100) MTB
NiMh Rayovac       AA 1600ma  1: 05/09/09 -+1424mAh (Discharge BC-900  350) MTB
NiMh Rayovac       AA 1600ma  1: 05/02/09 - 1238mAh (Refresh2  BC-900  200) MTB
NiMh Rayovac       AA 1600ma  1: 05/02/09 - 1205mAh (Refresh1  BC-900  200) MTB
NiMh Rayovac       AA 1600ma  1: 05/01/09 - 1268mAh (Refresh1  BC-900  500) MTB
NiMh Rayovac       AA 1600ma  1: 04/30/09 - 1292mAh (Refresh1  BC-900  700) MTB
NiMh Rayovac       AA 1600ma  1: 04/10/09 # 1.68VDC (Impedance Check C9000) MTB#
NiMh Rayovac       AA 1600ma  1: 02/11/09 * 1174mAh ( BREAK-IN C-9000     ) MTB*
NiMh Rayovac       AA 1600ma  1: 02/09/09 - 1219mAh (Discharge C-9000  100) MTB
NiMh Rayovac       AA 1600ma  1: 02/08/09 -  185mAh (Charge    C-9000  800) MTB
NiMh Rayovac       AA 1600ma  1: 01/24/09 - 1365mAh (Refresh   BC-900  700) MTB

NiMh Rayovac       AA 1600ma  2: 05/11/09 -+1760mAh (Discharge BC-900  100) MTB
NiMh Rayovac       AA 1600ma  2: 05/09/09 -+1276mAh (Discharge BC-900  350) MTB
NiMh Rayovac       AA 1600ma  2: 05/06/09 - 1189mAh (Refresh5  BC-900  200) MTB
NiMh Rayovac       AA 1600ma  2: 05/05/09 - 1180mAh (Refresh4  BC-900  200) MTB
NiMh Rayovac       AA 1600ma  2: 05/04/09 - 1160mAh (Refresh3  BC-900  200) MTB
NiMh Rayovac       AA 1600ma  2: 05/04/09 - 1155mAh (Refresh2  BC-900  200) MTB
NiMh Rayovac       AA 1600ma  2: 05/03/09 - 1150mAh (Refresh1  BC-900  200) MTB
NiMh Rayovac       AA 1600ma  2: 05/02/09 - 1161mAh (Refresh2  BC-900  500) MTB
NiMh Rayovac       AA 1600ma  2: 05/01/09 - 1160mAh (Refresh1  BC-900  500) MTB
NiMh Rayovac       AA 1600ma  2: 04/30/09 - 1168mAh (Refresh2  BC-900  700) MTB
NiMh Rayovac       AA 1600ma  2: 04/30/09 - 1158mAh (Refresh1  BC-900  700) MTB
NiMh Rayovac       AA 1600ma  2: 04/10/09 # 1.84VDC (Impedance Check C9000) MTB#
NiMh Rayovac       AA 1600ma  2: 02/14/09 * 1125mAh ( BREAK-IN C-9000     ) MTB*
NiMh Rayovac       AA 1600ma  2: 02/12/09 - 1108mAh (Discharge C-9000  100) MTB
NiMh Rayovac       AA 1600ma  2: 02/11/09 -  149mAh (Charge    C-9000  800) MTB
NiMh Rayovac       AA 1600ma  2: 01/28/09 - 1288mAh (Refresh   BC-900  500) MTB
NiMh Rayovac       AA 1600ma  2: 01/24/09 - 1198mAh (Refresh   BC-900  700) MTB

I've begun moving my old, non-LSD cells REFRESH cycles from my 'old' La Crosse BC-900 to my 'new' Maha MH-C9000 due to the independent (i.e not tied to 2-to-1) and more varied (4 vs 19) Charge/Discharge rates. When 'Refreshing / Cycling Multiple Times', I discharge @ 100mA to attempt to discharge as much as possible but I charge at as high a rate as I can without generating excessive heat. When 'Charging / Cycling Once', I discharge @ 0.2C to have a standard reference to compare to (ala 'Break-In').

Also note that WARM is not HOT and both are relative. My older, non-LSD cells do get warmer than my new LSD cells but an old RadioShack Indoor/Outdoor Thermometer confirms they're not exceeding 120°F. (You can also unplug the BC-900 and get the thermistor readings during boot up.)

 

[Mr Happy]

I have a hunch (unproven) that routinely charging cells at 200 mA on the BC 900 slowly but surely wrecks them. You won't notice it immediately, but after a few dozen cycles of such treatment the cells will have high internal resistance and reduced total capacity.

 

[bob_ninja]

I have a hunch (unproven) that routinely charging cells at 200 mA on the BC 900 slowly but surely wrecks them. You won't notice it immediately, but after a few dozen cycles of such treatment the cells will have high internal resistance and reduced total capacity.

Besides older BC-900, also some younger Eneloop chargers use only 300mA rate. You can find a recent post with a link for a PDF chart for Sanyo/Eneloop chargers. I ended up with the slow one, 300 mA.

So why would Sanyo use such a slow rate then??!?!?!
I don't question validity of your suggestion. Just find it strange that Eneloop chargers would still use such a slow rate when most others are higher.

At some point here I read a rule that charge rate should match the discharge rate. For instance I use a set of cells in gizmos that draw about 300 mA so according to this rule slower 300 mA rate would be appropriate.