MH-C9000 and Eneloops charge rate

[45/70]

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?

I've been using individual rechargeable cylindrical nickel based cells (ie. not "packs") since the early 80's and NiMH cells in particular since they first came to the consumer market. Here is how I maintain the different chemistries.

NiCd. I run either a complete use cycle (ie. down to an OC voltage of ~1.20 Volt) every time I use them, if possible. Every one to two months when they are being used, I run a "break-in" cycle. For storage, I discharge them to 1.20 Volts, or less, and store them at room temp. I do not attempt to "top up" NiCd cells when in storage. This only promotes crystalline growth and the associated voltage depression due to self discharge during storage. When removing from storage, I revitalize the cells with a "break-in" cycle.

Traditional NiMH. I run these through a complete use cycle every month, or so (preferably not each cycle) and do a "break-in" every 3-6 months. If the cells are not frequently used, 3 months, and if they are in pretty much continuous use 6 months. For storage I store them with a small amount of charge, eg. 1.25 Volts or so OC, at room temperature. When checking stored cells, if the voltage drops below ~1.20 Volts, I charge them up to 1.30 Volts, or so and put them back in storage (The voltage usually drops to ~1.25 Volts after a short time). When removing from storage, I run a "break-in" cycle.

LSD NiMH. This chemistry has proven to be pretty much ideal in that it truly requires less diligent maintenance. I generally run these cells through a complete use cycle (ie. down to 1.20 Volt) at least every 2-3 months by default. At approximately 6 month intervals, I run a "break-in", but I haven't panicked if this doesn't happen and am satisfied as long as a "break-in" is performed once per year. For storage, I do the same as for traditional NiMH cells, as above. When removed from storage however, I only run a "break-in" if the cells have been stored for more than six months. Otherwise, I just charge them up normally, but do stick to the "break-in" schedule of 6-12 months.

I don't really use the R&A function very much. What I do find it useful for, is when "good" cells show signs of not holding voltage well under load (voltage depression). A "break-in" would likely be superior, but the R&A function saves time, and if the cells, particularly the LSD variety, have not been "out of the loop" for very long, the R&A seems to work well, and of course is much faster. It is important to note, that even LSD cells will lose their ability to hold voltage under load, when not used for long periods. That has been my experience anyway.

The functions that I use the most with the C9000 are, charge, discharge, break-in and R&A, in that order. I have never used the cycling function, although I have used the similar "refresh" function in the past with my La Crosse BC-900, but don't really use it anymore.

I'll also add that I always perform a "break-in" cycle with new cells, regardless of their specific chemistry, discharging them first at a slow rate. Whether this really matters concerning LSD cells is debatable. My own observations have shown as much as a 150mAh advantage with eneloops, compared to not doing a break-in first. These cells had been "on the shelf" for about two years, and this may have been a factor.

Dave

 

[Dry-cell]

How much better would the results get if I do another R & A on them?.

 

[Dry-cell]

Kinda going off topic a bit but, how do you guys insert and remove your AA and AAA in the MH-9000?. What technique do you use?.

 

[Mr Happy]

Kinda going off topic a bit but, how do you guys insert and remove your AA and AAA in the MH-9000?. What technique do you use?.

I put the negative end in first, push it down and backwards, and then drop in the positive end. After that I rotate the cell a few times to ensure good contact. While rotating the cell I hold it down firmly so it doesn't rise up and out of the slot.

 

[Dry-cell]

That's what I do to insert them too. Do you do the same when you remove them or do you lift the negative end up first?.

Do you clean up scratches on the nipple and bottom contact, or just leave them be?. If you do, then what do you use?.

 

[45/70]

......Do you do the same when you remove them or do you lift the negative end up first?.

Particularly with AAA cells, if you either install the negative end last, or remove it first, you'll end up tearing the shrinkwrap that wraps around the end of the cell. Anymore though, few AAA cells have wrap that actually goes around the end of the cell. Still, it's better (and easier) to always install the negative end first, and remove last.

As for scratches, I've had little problem with them. Provided you press the negative end towards the contact first, when installing, or removing cells, scratches are not really a problem.

Dave

 

[billcushman]

Dry-cell, you are NOT inserting batteries correctly as instructed by the Maha Manual. Go to page two of the manual, look at the right side of the page for the section called Operations, look at the drawings shown under item 3. The drawings clearly show the correct way to insert AAs and AAAs. Remove the batteries by following the reverse of the insertion process. This method works perfectly and prevents damaging contacts.

You have been advised many times by me and others to perform Break-In on new batteries. No matter how many times you repeat Refresh and Analyze, you will NEVER accomplish the desired results. Look to the left of the insertion instructions in the Maha Manual, and you will read that Maha clearly recommends you perform Break-In on new batteries. You should follow the instructions if you want the best for your Eneloops. Your method is NOT correct.

 

[Dry-cell]

Yeah in the manual in the first picture it shows a person inserting the positive end first using a AA battery. In the second picture it show a person inserting a AAA with negative end first. What I do is place the negative end first, push down and drop in the positive end. It clicks into place. By the way, I have the pdf manual printed out and in a binder with all my other info. I always have it open when using the charger.

So when you remove a AA battery you lift the negative end first, right?. With a AAA battery you remove the positive end first?.



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[Mr Happy]

So when you remove a AA battery you lift the negative end first, right? With a AAA battery you remove the positive end first?

Actually, with AA batteries I lift the positive end first. With AAA batteries this is too fiddly, so I tend to "ping" the negative end out of the slot. I don't have the issue of tearing the wrapper that 45/70 mentioned since any AAA cells of mine that had wrap-around insulation no longer do -- I have carefully snipped it off flush with the end of the cell.

 

[45/70]

Regardless of whether your installing/removing AA, or AAA cells, if the wrapper does wrap around the negative end of the cell (as it should), the contact will rip the wrapper, when installing the negative end last, or removing it first, it's a fact. The cell installation and removal procedure outlined in the manual has been discussed numerous times in the C9000 mega threads and the conclusion is, that the manual gives some pretty poor advice.

......With AAA batteries this is too fiddly, so I tend to "ping" the negative end out of the slot. I don't have the issue of tearing the wrapper that 45/70 mentioned since any AAA cells of mine that had wrap-around insulation no longer do -- I have carefully snipped it off flush with the end of the cell.

In your case Mr H, it may not be a problem then. I have noticed however, that even cells with a flush shrinkwrap, the wrap can still be damaged by the negative contact. Removing the negative end of the cell first tends to cause the wrap to lift up and exposes the side of the cell to some extent.

I have multiple digital devices that specifically caution not to use cells which do not have a wrapper that wraps around the end of the cell, due to the possibility of the cell(s) shorting against the body of the device. 4 AA digital cameras come to mind. Also, I've had AAA cells installed in 3 cell carriers that shorted out against the light body, when using AAA cells that did not have proper shrinkwrap, that wrapped around the end of the cell. As I said though, AAA cells with proper shrinkwrap are far and few between nowadays. The only ones I know of are La Crosse AAA cells, which are pretty crappy cells, but they do have proper shrinkwrap that extends around the bottom of the cell.

As far as removal of AAA cells from the C9000 being "fiddly", just grab that little sucker, push towards the negative contact, lift the positive end of the cell, and remove. Seems simple enough to me, and I don't have any problem doing it that way.

Dave

 

[billcushman]

On all of my Eneloop AAs, the negative contact projects past the wrapper which wraps around the body. On any battery with a flat bottom on which the wrapper extends around the contact surface, the wrapper will be damaged by sliding it on or off the negative C9000 contact. In this case, do NOT follow the Maha diagram.

 

[Mr Happy]

As far as removal of AAA cells from the C9000 being "fiddly", just grab that little sucker, push towards the negative contact, lift the positive end of the cell, and remove. Seems simple enough to me, and I don't have any problem doing it that way.

I know, I was just joking a bit -- small cells, fat fingers, and all...

As far as AAA cells with wrap-around insulation is concerned, I had to cut it flush otherwise I was getting poor or failed electrical contact in the C9000. The negative battery contact on the C9000 does not have the best of designs in my humble opinion, especially on my model.

 

[Dry-cell]

I'm discharging my four AA batteries that I recently did an Refresh and Analyze on, I set the discharge rate to 400mA. I'm going to let them rest for an hour after their finished, then do a Break-in on them. I wanna get the best capacity out of them. I really wish I had a Universal Power Supply though, it would make me less nervous. :sweat:

 

[Dry-cell]

After the discharge is complete for each, I just want to unplug the charger for a hour, instead of taking the batteries out and having to put them back in for when I do the Break-in. When I plug the adapter back in I'll be able to program each slot without it going into charge mode, right?.

 

[billcushman]

Dry-cell: Yes, when you plug the adapter back in you WILL be able to program each slot without the charger going into the charge mode. You must be reasonably fast however. The moment the display cycles and the unit is ready, push the Down button until you select Break-in. Then push Enter and push the Down button until you read 2000 mA (AA Eneloops). Push Enter to complete slot #1. Repeat the process for slots #2, #3, and #4.

If you make a mistake just unplug the adapter and start over. After finishing setting, check every slot and make sure the charge current is about 200 mA. The slots won't be exactly 200, you may read 195, 197, 202 etc, but all will be very close to 200. If everything looks OK you are set to go. Check the display about 22 hours after starting. If you catch the charger during the rest period after discharge, you can get the capacity of each cell. If you miss this and the charger enters the final charge cycle, you will have to wait to read capacity until after the unit finishes about 16 hours later.

Don't worry, if you should experience a power interruption no harm will be done. If this should happen, you can easily tell by looking at the display. If the charge current is 1000 mA, you had a power interruption. No harm will be done.

 

[Dry-cell]

Thank's Bill. I'm just going to unplug the adapter after the discharge is complete and remove the batteries. That way I won't need to rush, even though it's easy to program.

 

[Mr Happy]

I really wish I had a Universal Power Supply though, it would make me less nervous.

Just for info though, I think you mean an Uninterruptible Power Supply.

 

[Dry-cell]

The Eneloops have been on Break-in now for about 20-25min, hopefully they run they're course, without issue.

Edit: I was considering putting a cookie sheet underneath the charger as a safety measure.

 

[Dry-cell]

Just for info though, I think you mean an Uninterruptible Power Supply.

Your right, my mistake.

 

[Dry-cell]

It's on the last rest now before the final 16h charge. The results are better, hopefully I see even higher numbers when complete. The second discharge took ruffly 319-327 minutes!.

Not final Break-in results!

Slot 1: 1992 mAh

Slot 2: 1987 mAh

Slot 3: 1976 mAh

Slot 4: 1998 mAh