MH-C9000 and Eneloops charge rate

[Dry-cell]

I'm sure their better than the results I would get from the Sanyo charger, right?. 39 to 45 hours to complete seems a bit much. I put them through the Refresh and Analyze because it takes several charge and discharges to reach close to the capacity of the battery.

 

[Mr Happy]

I sure their better than the results I would get from the Sanyo charger, right?. 39 to 45 hours to complete seems a bit much. I put them through the Refresh and Analyze because it takes several charge and discharges to reach close to the capacity of the battery.

Personally, I wouldn't be concerned. Just use the batteries and don't worry about it. The capacity on the battery is a "theoretical" number, not a "this is what you will actually get" number. My Eneloops also give about 1800 mAh on Refresh/Analyze. Once I know this number, it becomes my benchmark for future tests. So in future, if I saw 1700 mAh that used to be 1800 mAh I would know the battery is fading.

 

[Dry-cell]

I keep my batteries in a new clear case for tool bits, fishing lures, and such, you know the ones with the seperators. That way I can keep them in pairs and have them matched together.

 

[billcushman]

I have two MH-C9000s and have charged about 40 AA Eneloops many times over the last several years. I have always set the charge current at 600mA. So far all of the batteries are still in excellent condition.

I recently purchased some Eneloop 1500s and Apple LSD batteries. Here is how they tested in the Break-In Mode.

The capacity (mAh) of the Eneloop 1500 batteries tested as follows:
2081.2088, 2089, 2084, 2082, and 2076 Average = 2083.3 Std. Dev. = 4.4

The capacity (mAh) of the Apple LSD batteries tested as follows:
2065, 2078, 2053, 2077, 2054, and 2077 Average = 2067.3 Std. Dev. = 10.7

Both the Eneloop 1500 and Apple LSD batteries tested at slightly higher capacity than the standard Eneloop AAs. Most of those tested at 1950 to 2000 mAh. All Eneloop batteries I own have met specifications when tested in the Break-In Mode on the MH-C9000.

 

[mrlysle]

Dry-cell. I know it's a long process but I'm sure you'll end up with a higher mah reading after doing a "break-in" cycle on your new C-9000. All of my Eneloops have come out OVER their rated capacity after a break in cycle! The AA's all show over 2000 mah, and my AAA's all show over 800 mah. For instance, the last break in I run on a package of AA's gave me 2088, 2076, 2055, and 2073 mah. BTW, these were "brand new" "never used" Eneloops. I dis-charged them first, then run a "break-in" cycle on them, but I'm confident you would get the same results on cells that had been used several times before running the "break-in" cycle. "Break-in" cycle is the best cycle to use on the C-9000 if you want to see max capacity from your cells, but like others have said, don't worry too much about it yet. Just charge up a couple sets so you have something to use in your lights, and while your enjoying them, go ahead and run a "break-in" cycle on a few. It does take FOREVER so only run it when you've got some charged and useable. You won't hurt them just by charging them, even if they weren't completely dis-charged. That's what is soooo nice about the LSD Eneloops. They're top performers in my book and your new C-9000 will really make them "shine"! (pun intended) :naughty:

 

[s0lar]

One reason the refresh/analyze gives result around 1800mAh istead of 2000mAh could be that you do not fully charge the batteries with the MAHA C-9000.
As I said before, the charge termination is often done at 1.48V instead of at the -dV point. It terminates charging prematuraly. In the end it will give you more cycles but slightly lower performance.
The MAHA C-9000 continues to charge at 100mA for 2 hours after fast-charging is terminated. By removing the cells right after the fast-charge you can then easily see in a test that the cells are not yet fully charged.
Reading the mAh that went in and multiplying by 0.9 will give you an approximation of the capacity inside the cell.

 

[Dry-cell]

I left the batteries in the charger the full time until it said done for each cell (Charge/Rest/Discharge/Rest/Charge). I then wrote down the results for each battery, then removed each one before unplugging the charger. I put them away in the storage case afterwords.

Do you guys use your batteries strait out of the charger, or do you let them rest a certain period of time?.

 

[45/70]

Do you guys use your batteries strait out of the charger, or do you let them rest a certain period of time?.

Hi Dry. You can do it either way. Cells fresh off the charger will yield slightly higher capacity, as even LSD cells loose a bit of their capacity soon after removing from the charger.

On the subject of discharging cells at different rates, such as refreshing using a 500mA discharge rate vs. "breaking in" using a 400mAh rate, the slower the discharge rate, the higher the capacity will be. That is to say that the same cell discharged at a 500mA rate, will always result in less capacity than if the same cell were discharged at a 400mA rate. This is because at slower discharge rates, the cell is actually discharged farther than at higher rates, due to the cell voltage remaining higher for longer at low discharge rates, thus effectively allowing a deeper discharge.

Dave

 

[Dry-cell]

Thanks for the info 45/70. I chose a 500mA discharge due to the chart below, I was going to use 400mA to begin with (0.2 x 2000mAh =400mA). I can always do it next time.

http://www.mahaenergy.com/store/mhc9000faq.asp
What are the recommended charging and discharging current for my battery?

The recommended charging current is 0.5C, or 0.5 times the battery capacity. The recommended discharging current is 0.25C, or 0.25C times the battery capacity. Here are some settings for common batteries:

2700mAh Charge: 1300mA Discharge: 700mA

2650mAh Charge: 1300mA Discharge: 700mA

2500mAh Charge: 1200mA Discharge: 600mA

2300mAh Charge: 1100mA Discharge: 600mA

2200mAh Charge: 1100mA Discharge: 600mA

2100mAh Charge: 1000mA Discharge: 500mA

2000mAh Charge: 1000mA Discharge: 500mA

1000mAh Charge: 500mA Discharge: 200mA

900mAh Charge: 400mA Discharge: 200mA

850mAh Charge: 400mA Discharge: 200mA

800mAh Charge: 400mA Discharge: 200mA

700mAh Charge: 300mA Discharge: 200mA

650mAh Charge: 300mA Discharge: 200mA

600mAh Charge: 300mA Discharge: 200mA

 

[Dry-cell]

I should have asked this before I started another Refresh & Analyze on my other 4 new AA Eneloops. Like the Break-in mode, do you guys recommend a discharge prior to running a Refresh & Analyze?. If so, how long do you rest the batteries after discharging them before running the Refresh & Analyze mode?. This time I'm discharging @ 400mA instead of 500mA.

The batteries are going to be used in my new flashlight that's coming soon, and my digital camera.

 

[Dry-cell]

My second Refresh and Analyze using with my other pack of Eneloops, finished not long ago. Right now I'm letting the charger apply a top-off charge for an 1h 1/2 this time (I need my rest so I'm not leaving it for 2h). It took around 10 hours to complete! (around 11h 30min with top-off charge). My results are a bit better, not really worth the extra time it took using a 400mA discharge rate instead of 500mA. For some reason the second battery I put in took the longest to complete (a few minutes more) but got the best result.

Refresh and Analyze

Slot 1: 1795 mAh, Min 292, Volt 1.45

Slot 2: 1802 mAh, Min 296, Volt 1.46

Slot 3: 1798 mAh, Min 291, Volt 1.46

Slot 4: 1785 mAh, Min 292, Volt 1.45

Batteries are dated 2010

 

[bbb74]

I should have asked this before I started another Refresh & Analyze on my other 4 new AA Eneloops. Like the Break-in mode, do you guys recommend a discharge prior to running a Refresh & Analyze?. If so, how long do you rest the batteries after discharging them before running the Refresh & Analyze mode?. This time I'm discharging @ 400mA instead of 500mA.

The batteries are going to be used in my new flashlight that's coming soon, and my digital camera.

I'm curious what other people think about this too. I usually do a discharge before a R&A. I only do an R&A every 3 months or so, theoretically I figure this is to reduce crystal formation, so I also figure that by discharging before charging, it will help shrink the crystals before charging them up bigger in the charge part of the R&A cycle. Usually there's not heaps to discharge because I run the batteries down to 10-20% in something useful before starting.

I'm also curious to know how often everybody does a "refresh" R&A cycle on their LSD and non-LSD batteries? Never? Every X months? Every X times used?

 

[Russel]

Refresh and Analyze starts by charging the cells using the same termination methods as the standard charge mode. So, it really doesn't matter if the cells are charged or not when you start refresh and analyze. If they are charged, they should terminate in less time, rest, then discharge, etc. If they are not, they will simply take longer to charge.

Break-in is different in that it is a timed charge at a low rate. Break-in mode requires you to set the cell capacity, then the charger uses a C/10 charge rate timed for 16 hours. (Eneloops at C/10 = 200mA.) Charging at C/10 is not as efficient as charging at higher rates, that is why it is timed for 16 hours rather than 10 or 11. NiMH cell are much more tolerant of overcharging at C/10 so starting a break-in cycle with cells that are already charged shouldn't harm them. But, that just goes against the grain with me. I always discharge cells before using break-in mode...I just feel better about it.

My NiMH cell care method:

I run a break-in on all new cells (discharged first) then run a break-in once a year. As I understand it, break-in help to distribute the electrolyte in the cell.

I charge Eneloops at 1000mA as needed. If a cell hasn't been discharged enough over the last three months in normal use (such as in TV remotes) I cycle it, 400mA discharge, 1000mA charge, and consider it good for the next three months. I happen to use cycle for this but refresh and analyze would work just as well.

If I'm not using in a cell, I discharge it, charge it at 1000mA for about 10 minutes (so it has some charge) and place it in ziplock bag in the refrigerator for storage. When I want to use it, or every three to six months, I take the bag out of the refrigerator and allow it to come up to room temperature over night, and charge it. If it is going back into storage, discharge, charge 10 minutes at 1000mA and back into the ziplock and the refrigerator.

I have had good results with this method. I remember the first NiMH batteries that I got years ago. Charge them up one week later they were dead whether you used them or not.

 

[bbb74]

Russel, interesting that we both picked 3 months, what made you choose that period? How have your batteries being treated in this way held up, ie do you know how much capacity they have lost over time (years?)? I haven't had mine long enough to really see any difference yet. I'm doing a long term test to see if 3 mths vs 6mths vs 12mth recycling makes any difference in low usage devices.

The long term ones you keep in the fridge, so you take them out and then just do a quick discharge and then a slight recharge - you don't do a full cycle on them?

 

[Russel]

Russel, interesting that we both picked 3 months, what made you choose that period?

It seems about right for NiMH chemistry. I have some NiCad batteries for portable tools that I cycle once a month.

How have your batteries being treated in this way held up, ie do you know how much capacity they have lost over time (years?)? I haven't had mine long enough to really see any difference yet. I'm doing a long term test to see if 3 mths vs 6mths vs 12mth recycling makes any difference in low usage devices.

My oldest Eneloops are about 2 years old. None of my Eneloop cells measure below 1800mAh.

The long term ones you keep in the fridge, so you take them out and then just do a quick discharge and then a slight recharge - you don't do a full cycle on them?

I take them out of the fridge, let them warm overnight. Then charge them completely followed by a discharge and finally and partial charge. Then they go back in the fridge.

 

[billcushman]

If you want the best for your Eneloops, please discharge and then perform Break-In. This will give you accurate capacity information and condition the Eneloops for best performance. Refresh and Analyze is NOT the best procedure for new batteries. Others have recommended this to you, but you seem reluctant to do it. Please abandon Refresh and Analyze and perform Break-In. You will be pleased with the results.

 

[Eismagier]

Refresh & Analyze tops off the cells at the selected rate instead of forcing a timed charge into them, so prior discharging will only cause the initial charge to take longer.

EDIT: Whoops, didn't see the second page. This was meant as a reply to an earlier post.

 

[Dry-cell]

----------------------------
@billcushman

Yes, I know that I would get better results with a Break-in but I'm afraid to leave the charger running for that amount of time.
----------------------------

Anyway, here's some of the info from the label on the back of the charger.

0K0AA

Manufactured by
Maha Energy (Taiwan) Corp
Made in Taiwan

A04-3713419-495

 

[Dry-cell]

It would be nice if you could see the capacity of the batteries rise after it says done and is in trickle charge.

 

[billcushman]

Dry-cell, I have performed Break-In on about 70 AA cells (Eneloops and others) over several years. Don't be afraid to leave the Maha C9000 unattended. If power should be interrupted, the charger will default to 1 A Charge mode, and no harm will be done. Try Break-In, it takes about two days, including performing discharge first. If you want capacity readings on Discharge, set the discharge current at 400 mAh, otherwise the default discharge current of 500 mAh is fine and slightly faster.