Powerex MH-C9000 - new Sanyo Eneloops

I'm new to the MH-C9000 charger and Eneloop batteries. I've been doing extensive reading here in the forums and gather that a discharge/break-in is highly recommended for new (unused) batteries? I'm using the Eneloop 1500s that retain 75% capacity up to 3 yrs. I need advice from the very beginning as far as what modes will give me best battery life/usage. The main appliances used are a digital camera (4 AA), remote control (4 AAA) and miscellaneous devices that use up to 1-2 AA/AAA.

To begin, how long does a cycle (break-in, R&A, charge etc.) last for batteries that are unused; is there a time period of non-use when the batteries should receive another cycle before use in a device?

I read where a Charge was only required; did this on 4 AAA eneloops after they showed signs of degradation. These batteries were used straight out of the package (no break-in, R&A etc.). The C9000 results were:
Battery 1 582 mah 1.45v
" 2 628 mah 1.45v
" 3 628 mah 1.44v
" 4 615 mah 1.44v MIN were 97 - 104

Will the mah capacity be higher if I did a Break-in, discharge/Break-in? What is the advantage/benefit of doing the discharge first?

Say, when the devices no longer functions properly (weak batteries) is a Charge only required. If so, should the batteries be discharged before applying the Charge or is a straight Charge sufficient?

On a brand new 4pk AAA the voltage is 1.338v for all 4. Would applying a cycle increase the voltage/mah? Can you get a direct maH reading on the C9000 for batteries without running them through a cycle?

As a newbie I hope I'm understandable......... in advance thanks!

Hello Radunn,

Welcome to CPF.

The Break In function involves charging for 16 hours, resting for an hour, discharging for 5 hours, resting another hour, then charging again for 16 hours. That adds up to 39 hours.

Charge time depends upon how discharged the cell is, and the charge current you select. Discharge time depends upon the discharge current you select and the capacity of the cell.

The R&A function involves both charging and discharging.

The main purpose in cycling cells through charge and discharge cycles is to evenly distribute the electrolyte within the cell. In normal use you don't worry too much about this and only do a complete discharge every few months to eliminate any "memory effect" that may be forming.

If you have more cells than you normally use, you have two options. The best is to purchase more lights and use them... :devil: Or, you will have to store them. Storage is hard on cells and cells that have been stored can benefit from either a Break In or R&A cycle.

Eneloop cells seem to just work well. They don't see much benefit from either the Break In or running R&A cycles on them. Sometimes you will see a little improvement, but it is usually minor. When running a Break In on them it is better to run a discharge first. This will limit the amount of overcharge on the cell.

In most cases when you have run a cell down, just recharge it. You can set up a system to manage your cells by finding a way to keep track of them, and then when you change the clocks from daylight savings to normal time use that as a reminder to run a charge/discharge cycle on your cells. Record the capacity and log it for future use. Some people only do this once a year, others do it 4 times a year. Pick a time frame that suites you.

To determine the capacity of a cell it needs to be discharged. To determine the full capacity of a cell it needs to be charged first, then discharged.

If you prefer "vibrant" cells use them frequently and at a minimum do a discharge followed by a Break In once a year. Note the capacity and recycle the cell when it falls below 80% of its initial measured capacity.

Tom

Excellent explanation, SilveFox.

SilverFox said:

The Break In function involves charging for 16 hours, resting for an hour, discharging for 5 hours, resting another hour, then charging again for 16 hours. That adds up to 39 hours.

The R&A function involves both charging and discharging.

To determine the capacity of a cell it needs to be discharged. To determine the full capacity of a cell it needs to be charged first, then discharged.

If you prefer "vibrant" cells use them frequently and at a minimum do a discharge followed by a Break In once a year. Note the capacity and recycle the cell when it falls below 80% of its initial measured capacity.

Tom

Click to expand...

Thanks for the valuable information; it's saved as a file. Do I have this right; for a new cell (to determine the current capacity) it should be discharged? What is "full capacity"; is it maH after charge/discharge? My thinking is that a discharge/charge = full capacity. I open for correction. Again thanks!

Hello Radunn,

The difference between capacity and full capacity comes into play with people measuring the amount of self discharge cells experience. If you charge a cell and set it aside for a month, you may be interested in what it has left for capacity. In this case you would simply do a discharge to see how much was left. On the other hand if you want to now the full capacity of the cell you would charge it first, then do a discharge to determine its full capacity.

Tom

SilverFox said:

If you charge a cell and set it aside for a month, you may be interested in what it has left for capacity. In this case you would simply do a discharge to see how much was left. On the other hand if you want to now the full capacity of the cell you would charge it first, then do a discharge to determine its full capacity.

Tom

Click to expand...

Thanks... regarding the above, either choice I decide that results with Discharge, I assume it's necessary to Charge that battery before using it? What Mode is recommended? Again, I assume Charge. Is there a benefit for using a volt-ohm meter to measure voltage?

Hello Radunn,

It depends upon what you are planning to do with the cell. After it is discharged, it can be stored. If you need power from it, then it will need to be charged before use. The charge mode works great to charge cells.

I always encourage people to have a voltmeter and to use it, but the C9000 reports voltage so it is not totally necessary.

Tom

SilverFox said:

Hello Radunn,

It depends upon what you are planning to do with the cell. After it is discharged, it can be stored. If you need power from it, then it will need to be charged before use. The charge mode works great to charge cells.

I always encourage people to have a voltmeter and to use it, but the C9000 reports voltage so it is not totally necessary.

Tom

Click to expand...

Well, this is new to me. Storing NiMH cells in a discharged state. Wouldn't that cause the cell to self-discharge even more and get into a region where it's lifetime and capacity are reduced and non-recoverable?

mousewizard said:

Well, this is new to me. Storing NiMH cells in a discharged state. Wouldn't that cause the cell to self-discharge even more and get into a region where it's lifetime and capacity are reduced and non-recoverable?

Click to expand...

I understand that Eneloops lose about 15% of the charge in about three years ... Then they lose 15% of the remainder over the next three years and so on ... I doubt whether most users would keep them several years without using or charging them.

The whole idea about LSD cells is that you charge them and keep them till you need them ... So , even after six years from the charge , they should still have over 70% left in them.

I tend to top-up all my LSD cells regularly every six months (whether they need it or not) , though the last time I somehow forgot and it was fifteen months between charges.

I would hate to go back to non-LSD cells when I was topping up every month or so.
.

Yeah, but silverfox stated he was storing them after discharging them.

mousewizard said:

Yeah, but silverfox stated he was storing them after discharging them.

Click to expand...

I always store Eneloops in a discharged, or slightly charged state. Slightly charged being about 10% state of charge. I cycle the batteries every 3 to 6 months and, if I don't need to use them, return them to storage. When I say cycling the batteries, I am refering to charging, then discharging the cells if they are going back into storage. I haven't had any problems with my Eneloops over the last few years using this method. One note, I do run a "break in" cycle on all of my Eneloops with a Maha MH-C9000 charger once a year.

Russel said:

I always store Eneloops in a discharged, or slightly charged state. Slightly charged being about 10% state of charge. I cycle the batteries every 3 to 6 months and, if I don't need to use them, return them to storage. When I say cycling the batteries, I am refering to charging, then discharging the cells if they are going back into storage. I haven't had any problems with my Eneloops over the last few years using this method. One note, I do run a "break in" cycle on all of my Eneloops with a Maha MH-C9000 charger once a year.

Click to expand...

When I buy Eneloops they are pretty well fully charged ... It doesn't take much charge to fill them up ... It is quite possible that when you buy Eneloops , they are not that recent ... They could even be a year or two old ... Based on this , I keep mine fully charged and top up (when I remember) every six months or so ... I top up all my spares even if they were very recently charged ... I just keep a note of the date that they were all topped up ... I have not had trouble with my Eneloops in the last two or three years ... I like to be able to go into the drawer and simply take out the required number of Eneloops without having to put them on charge for a few hours (charging time plus two hours topoff).

For my purposes , I can't see the point in keeping batteries uncharged ... I do the same with my 18650's ... I don't mind buying new cells every few years , though I've had my Li-Ions about three years now ... I don't know how old the Li-Ions were when I bought them but they are still working great even though they are only cheap Ultrafires ... When the 18650's eventually die , I will buy Panasonic replacements (eventually).
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Hello Mousewizard,

The self discharge rate of cells reduces greatly as it approaches full discharge. You go from 100% to 90% fairly quickly, but it takes forever to go from 15% to 10%.

The low self discharge cells are different. If you want to store them charged and ready for use, that seems to work well. I still take any excess number of these cells and store them discharged.

To store an AA Eneloop cell for example, I discharge it at 1.0 amps in the C9000. This leaves a bit of charge in the cell and is different from doing a discharge at 0.1 amps. In the old days, some of us would short the cell out and store it that way over the winter months when we weren't using our RC cars. Now days it seems that people switch the battery from the car to the 4X4 and run in the snow...

Tom

Wow. Talk about a set of mixed advice!

Basically, I'm trying to preserve inventory. That is; store batteries for as long as possible so that they're still useful when I bring them into service. Many, many years would be nice.

The current method I use (storing charged and topping off with very light charge rates) is based on my impression that chemistry doesn't like to go back and forth all the time. Losses are incurred with each cycle and the amount of loss depends on the depth of the cycle. So "rocking" the battery in the top 10% of its capacity seems (to me) easier on the chemistry than storing discharged, then charging and discharging (basically, using up a cycle) once a year.

For example, I do this with the NiMH packs in my tools and the packs usually last so long the OEM packs aren't available as replacements by the time I need new ones. I did this with my EV as well and the pack lasted much longer than the dealer expected.

So, is there some new data out there or what?

Hello Mousewizard,

The concern with storing at a full charge has always been oxidative damage to the electrolyte and electrodes. The evolution in technology has seen a great improvement in electrolyte and electrode formulations. This may result in less concern in storage charge.

I expect cells to last 2 years from purchase. I am constantly surprised when they last longer than that. I currently have some that are going on 8 years and they are still going strong. These have been in use and in storage and when in storage they are stored discharged and give a periodic charge/discharge cycle.

The research has moved from NiMh chemistry to Li-Ion chemistry, so there isn't much new, except for the low self discharge chemistry.

Tom

Shorting and storing individual NiCd cells once they're fully discharged is fine. I'm not sure I'd recommend it for Eneloops though. I store mine charged and ready to use.

For long storage of several years or more, I'd probably leave them in the packaging, or about half charged in a cool, dry, dim place. I would not repeatedly top them off, though I might do a slow cycle on them every six months or once a year. I think repeatedly topping them off would add some extra wear on them.

Is there a need to keep a load of batteries for many years ? ... Why not just keep a few spares and buy new (recently manufactured) cells as needed.

I can see that it would be necessary to have a supply of certain cells or batteries if they were no longer being manufactured , but AA and AAA will be here for many more years.

At the moment , I have eight AA Eneloops and four AA Hybrios spare plus eleven assorted LSD AAA cells ... I also have two unprotected 18650 cells plus one protected plus three Lithium CR-123's and three RCR-123's spare ... As my batteries eventually die , I will buy more ... All my torches are equipped with batteries , though some are Lithium primaries (in the car) and some are Duracell Ultra-powers (in give-away torches).

I know it is a personal choice , but I only keep the bare minimum of spare batteries ... I have too many LSD AAA's spare at the moment and would normally only have three or four , but I took a few out of remotes ... I don't now use rechargeable cells in clocks and remotes etc , so my batteries are only for torches and radios ... All my clocks and remotes are using Duracell Ultra-powers (dated 2017) which I had at a good price ... They seem to last forever ... So far I haven't had any problems with battery leakage ... I do tend to tentatively look at the batteries in my remotes occasionally though when I remember.
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SilverFox said:

Hello Mousewizard,

The concern with storing at a full charge has always been oxidative damage to the electrolyte and electrodes. The evolution in technology has seen a great improvement in electrolyte and electrode formulations. This may result in less concern in storage charge.

I expect cells to last 2 years from purchase. I am constantly surprised when they last longer than that. I currently have some that are going on 8 years and they are still going strong. These have been in use and in storage and when in storage they are stored discharged and give a periodic charge/discharge cycle.

The research has moved from NiMh chemistry to Li-Ion chemistry, so there isn't much new, except for the low self discharge chemistry.

Tom

Click to expand...

OK. I can see the concept. I currently top off the LSD batteries once every six months, and cycle them once a year. I think I'll plan to partially discharge them (about 25%), and then cycle them once every two years and monitor them to see how they hold up. As for the standard NiMH, I think I'll do the same, and then monitor how long they take to self-discharge and cycle them once they get to about 1/2 capacity. How does that approach sound to you?

march.brown said:

Is there a need to keep a load of batteries for many years ? ... Why not just keep a few spares and buy new (recently manufactured) cells as needed.

I can see that it would be necessary to have a supply of certain cells or batteries if they were no longer being manufactured , but AA and AAA will be here for many more years.

Click to expand...

I have my reasons. They make sense to me.

Hello Mousewizard,

Sounds like a good test...

Tom