Just recieved my Maha MH C9000 today! But I need some beginners help......

[roadwarrior]

Can't wait to start playing with this instrument, but being as I am a tad OCD, I want to make sure I play with it right. So I have a few questions I hoping you experts can help me with, with that said, please bear with me, if my questions seem dumb. I am a complete noob, who's only clue to date on these matters has come from the very knowledgeable folks on here that have taken the time to help me.

1. Is it okay to leave the Maha plugged in indefinitely , when I have no batteries inserted?

2. I have the following quads I have been rotating out of my application (a radio scanner) for approximately 2 months, Energizer AA 2300mAh I purchased new out of the package and a quad of CORUN AA 2300mAh that came with my scanner. What should I do first with either on my Maha? If it matters, I was using the Energizer PRO model CHPRO to charge them prior to receiving my Maha.

3. I have a quad of Duracell AA 2400mAh Ion Core, "Duraloops" brand new, still in the package unused I bought from Wally World yesterday. What should I do with them first?

4. My version is 0N0FA, can someone decipher that and tell me if I got the most current model?

I am sure I will have other questions once I start using the charger, which I will try and get answered by using the search function on here. I just wanted to initially get a few answered pertaining to the individual batteries I have on hand at the moment.

Thanks in advance guys!

P.S. I will gladly accept any and all feedback from anyone who owns or has owned the C9000, pertaining to new user advice, lessons learned, dos and don'ts, etc.... :thanks:

 

[Rosoku Chikara]

Can't wait to start playing with this instrument, but being as I am a tad OCD, I want to make sure I play with it right. So I have a few questions I hoping you experts can help me with, with that said, please bear with me, if my questions seem dumb. I am a complete noob, who's only clue to date on these matters has come from the very knowledgeable folks on here that have taken the time to help me...<snip>

Let me be the first to congratulate you on what I believe is an excellent purchase! I have been using my Maha C9000 for nearly 3 years, and I have found it to be a wonderful product. I am not anywhere near the "Maha C9000 Expert" of this forum, but let me tell you about my experience.

1. Is it okay to leave the Maha plugged in indefinitely , when I have no batteries inserted?

I have found no problems whatsoever with leaving my Maha plugged in "indefinitely" both with batteries inserted, and without. As you probably know, so long as cells are inserted, they are constantly receiving a low "trickle charge." I believe that you should leave them in for a minimum of 2 hours, to complete this trickle charge process (in order to completely top the cells off to their maximum capacity). But, I have not experienced any problems with leaving them inserted overnight, or even longer. Someone else may be able to tell you whether or not such a low trickle charge can or will eventually damage a good LSD cell, such as Eneloops (which I use). But, in the real world, I have experienced no problems whatsoever. (I guess you might eventually run into problems if you left cells in for days and days, or weeks and weeks... but, I am not sure of that.)

In any case, I do not believe the charger does anything at all without cells inserted, so I assume you could leave it plugged in for years. (Mine generally is.)

2. I have the following quads I have been rotating out of my application (a radio scanner) for approximately 2 months, Energizer AA 2300mAh I purchased new out of the package and a quad of CORUN AA 2300mAh that came with my scanner. What should I do first with either on my Maha? If it matters, I was using the Energizer PRO model CHPRO to charge them prior to receiving my Maha.

Sorry, I have no experience with the batteries you mention. But, I can tell you what I would do, if it were me. (One word of advice, the C9000 is a wonderful device, but it is not for the impatient. Some things simply take time... If you want to "enjoy" all the capabilities of your C9000, get used to putting cells in, and then "forgetting about them" for a while.) What I would do with such "unknown" cells, is attempt to determine how well matched they are. In an ideal world, you want your "quads" to be was perfectly matched as possible. Therefore, I would want to know, as accurately as possible, what the capacity of each cell is. In order to do that, I would run the "Cycle" Mode (2-3 cycles?), then a "Discharge," then the "Analysis" mode.

3. I have a quad of Duracell AA 2400mAh Ion Core, "Duraloops" brand new, still in the package unused I bought from Wally World yesterday. What should I do with them first?

Well, as you know from the fact that you call them "Duraloops", most of us on this forum believe that Duracell AA 2400mAh Ion Core are the FDK cells that are the same as Eneloops "Black" (Pro/XX) cells. Those are the only AA Eneloops I use, and I use a lot of them. For the past three years, straight out of the package, I have run a "Discharge," a "Break-In", another "Discharge," and then an "Analysis" on each cell, before using them. And, I have kept detailed records of the results in an Excel spreadsheet. (You mentioned "a tad OCD," and I will happily confess to more than "a tad," along with a quite a few other good people on this forum, I think.)

Also, I have always tried to purchase as many as possible at the same time. (Usually, 12 or 16 cells at a time.) Therefore, I do not start using any of the cells until all testing is completed for all cells. My reasoning is that I want to make the best possible "matching sets" for my various devices. I do not use any 18650 Li-Ion cells. But, I have a number of wonderfully bright flashlights that use sets of 3, 4, or even 6 cells. And, I keep spare sets on hand for all. (I also have a bunch of things that run on AAA, so I do the same thing with a large number of 900mAh Eneloop Pros. While keeping "Pros" in many of those devices is ridiculous "over-kill," I have a large number of low cost AAA->AA adapters, so that all those AAAs can be "robbed" and used in flashlights, if ever necessary.)

I do not try to keep track of individual cells. But, I do try to keep track of "matched sets" and I number each device, so that I know which set went into which device. (Fox example, I have several identical devices that use 4 x AAA cells, so I would lose track of which set was which, if the devices were not numbered. I have ended up numbering everything... just a tiny unobtrusive number inside the battery compartment.) I do not attempt to record each recharge capacity, which is not very accurate anyway. (I do usually glance at the screen to get a rough idea of how consistent the 4 cells are), but every now and then, I run another "Analysis" on that "matched set" which I do record in my Excel spreadsheet.

Having done all this for three years, my main conclusion is; that it was all unnecessary. Eneloops (even the Pros, and the regular white cells are said to be even more stable) are truly "rock solid." I see almost no change. (Remember, of course, that that your C9000 is not a scientific instrument, so there will be small variation in all its reading. But, it is certainly accurate enough for the purposes of making sure you do not use highly mis-matched sets that could result in cell damage due to "self re-charging" of weaker cells by stronger cells within the set, after the weakest cells are fully depleted.)

So, if you like, I am confident that you can take your new "Duraloops" out of their package, use them until they are "dead", and then simply recharge them. I do not think you are likely to ever have a problem. But, in my opinion, it would kind of "take the fun out of" owning a C9000. (Please note: I am not certain that it makes any difference, but I do try to "baby" my cells. I recharge AA at 600mA and AAA at 300mA. I always use the default 500mA discharge, because it is simplest.)

4. My version is 0N0FA, can someone decipher that and tell me if I got the most current model?

Can't help you here. Mine is 0L0JA. Perhaps someone can also tell me that mine means.

 

[ChrisGarrett]

Some have found that the display will grow dimmer over time, if left on a lot.

I unplug my Maha C9000 and sometimes put a piece of paper over the display while in use, to cut down on the light emissions. Why chance an electrical spike, or brown out?

It's one of the 'nits' about the Maha.

Chris

 

[roadwarrior]

I got it plugged into a surge protector to protect it in case of a spike. The display does not seem to bother me, however it is daytime here still....I may think differently at night.

Couldn't resist any longer, I am currently running a refresh - analyze on my Energizer quad. Hopefully I can decipher the results when its done.

 

[roadwarrior]

Let me be the first to congratulate you on what I believe is an excellent purchase! I have been using my Maha C9000 for nearly 3 years, and I have found it to be a wonderful product. I am not anywhere near the "Maha C9000 Expert" of this forum, but let me tell you about my experience.



I have found no problems whatsoever with leaving my Maha plugged in "indefinitely" both with batteries inserted, and without. As you probably know, so long as cells are inserted, they are constantly receiving a low "trickle charge." I believe that you should leave them in for a minimum of 2 hours, to complete this trickle charge process (in order to completely top the cells off to their maximum capacity). But, I have not experienced any problems with leaving them inserted overnight, or even longer. Someone else may be able to tell you whether or not such a low trickle charge can or will eventually damage a good LSD cell, such as Eneloops (which I use). But, in the real world, I have experienced no problems whatsoever. (I guess you might eventually run into problems if you left cells in for days and days, or weeks and weeks... but, I am not sure of that.)

In any case, I do not believe the charger does anything at all without cells inserted, so I assume you could leave it plugged in for years. (Mine generally is.)



Sorry, I have no experience with the batteries you mention. But, I can tell you what I would do, if it were me. (One word of advice, the C9000 is a wonderful device, but it is not for the impatient. Some things simply take time... If you want to "enjoy" all the capabilities of your C9000, get used to putting cells in, and then "forgetting about them" for a while.) What I would do with such "unknown" cells, is attempt to determine how well matched they are. In an ideal world, you want your "quads" to be was perfectly matched as possible. Therefore, I would want to know, as accurately as possible, what the capacity of each cell is. In order to do that, I would run the "Cycle" Mode (2-3 cycles?), "Discharge," then "Analysis" mode.



Well, as you know from the fact that you call them "Duraloops", most of us on this forum believe that Duracell AA 2400mAh Ion Core are the FDK cells that are the same as Eneloops "Black" (Pro/XX) cells. Those are the only AA Eneloops I use, and I use a lot of them. For the past three years, straight out of the package, I have run a "Discharge," "Break-In", and "Analysis" on each cell, before using them. And, I have kept detailed records of the results in an Excel spreadsheet. (You mentioned "a tad OCD," and I will happily confess to more than "a tad," along with a quite a few other good people on this forum, I think.)

Also, I have always tried to purchase as many as possible at the same time. (Usually, 12 or 16 cells at a time.) Therefore, I do not start using any of the cells until all testing is completed for all cells. My reasoning is that I want to make the best possible "matching sets" for my various devices. I do not use any 18650 Li-Ion cells. But, I have a number of wonderfully bright flashlights that use sets of 3, 4, or even 6 cells. And, I keep spare sets on hand for all. (I also have a bunch of things that run on AAA, so I do the same thing will a large number of 900mAh Eneloop Pros. While keeps "Pros" in many of those devices is ridiculous "over-kill," I have a large number of low cost AAA->AA adapters, so that all those AAAs can be "robbed" and used in flashlights, if ever necessary.)

I do not try to keep track of individual cells. But, I do try to keep track of "matched sets" and I number each device, so that I know which set went into which device. (Fox example, I have several identical devices that use 4 x AAA cells, so I would lose track of which set was which, if the devices were not numbered. I have ended up numbering everything... just a tiny unobtrusive number inside the battery compartment.) I do not attempt to record each recharge capacity, which is not very accurate anyway. (I do usually glance at the screen to get a rough idea of how consistent the 4 cells are), but every now and then, I run another "Analysis" on that "matched set" which I do record in my Excel spreadsheet.

Having done all this for three years, my main conclusion is; that it was all unnecessary. Eneloops (even the Pros, and the regular white cells are said to be even more stable) are truly "rock solid." I see almost not change. (Remember, of course, that that your C9000 is not a scientific instrument, so there will be small variation in all its reading. But, it is certainly accurate enough for the purposes of making sure you do not use highly mis-matched sets that could result in cell damage due to "self re-charging" of weaker cells by stronger cells within the set, after the weakest cells are fully depleted.)

So, if you like, I am confident that you can take your new "Duraloops" out of their package, use them until they are "dead", and then simply recharge them. I do not think you are likely to ever have a problem. But, in my opinion, it would kind of "take the fun out of" owning a C9000. (Please note: I am not certain that it makes any difference, but I do try to "baby" my cells. I recharge AA at 600mA and AAA at 300mA. I always use the default 500mA discharge, because it is simplest.)




Can't help you here. Mine is 0L0JA. Perhaps someone can also tell me that mine means.

Thanks for the great feedback! Initially when I read your post a while ago, for some reason it was cut off prior to the battery feedback. I got impatient and just had to play with it, so I am running a refresh - analyze on the Energizer quad. The manual suggested I just go ahead and charge them, but they had just been charged in my dumb charger a few days ago, so I figured just recharging them would be of no benefit.

I will follow your advice on the CORUNs once my scanner alerts me they are too low.

I'll run the Duraloops in my scanner right out the package.

The same day I pulled the trigger on the Maha, I ordered a quad of AA Eneloop Pros and a quad of AA Maha Powerex 2700mAh batteries, I am currently awaiting their arrival from Amazon.

:thanks:

 

[Rosoku Chikara]

...The manual suggested I just go ahead and charge them, but they had just been charged in my dumb charger a few days ago, so I figured just recharging them would be of no benefit...<snip>

I don't have my manual handy, but this doesn't sound right. (Perhaps, I am not understanding what you you are saying.)

I believe that the first thing that the C9000 does in "Analysis" mode (Refresh/Analyze) is charge the cell. So, I do not believe that they would recommend that you charge them first. If you were to do anything, you might want to discharge them first. (I believe that even the discharge is completely unnecessary, but since I started out doing it that way, I still do it.) That way, when the "Analysis" process begins, the first thing is does is fully recharge the cell. (But, as I say, I believe that this discharge is unnecessary, since all that would happen if the cell were already charged, is that the C9000 would immediately stop charging that cell.)

On the other hand, I do believe it is important to run a "Discharge" prior to a "Break-In."

 

[roadwarrior]

I don't have my manual handy, but this doesn't sound right. (Perhaps, I am not understanding what you you are saying.)

I believe that the first thing that the C9000 does in "Analysis" mode (Refresh/Analyze) is charge the cell. So, I do not believe that they would recommend that you charge them first. If you were to do anything, you might want to discharge them first. (I believe that even the discharge is completely unnecessary, but since I started out doing it that way, I still do it.) That way, when the "Analysis" process begins, the first thing is does is fully recharge the cell. (But, as I say, I believe that this discharge is unnecessary, since all that would happen if the cell were already charged, is that the C9000 would immediately stop charging that cell.)

On the other hand, I do believe it is important to run a "Discharge" prior to a "Break-In."

You are right....what the manual suggested was with batteries that have been in constant use like my Energizers, is to just recharge them "when needed" to..instead of the other options. Sorry, I mis-spoke.

I have also read from many on here the importance of discharging before break-in, I will be practicing that for sure.

What are the main things I need to be looking for when the refresh - analyze cycle is done?

 

[Mr Floppy]

Some have found that the display will grow dimmer over time, if left on a lot.

The display on mine is off when no batteries are inserted. The backlight on my 808m however has died though.

 

[ChrisGarrett]

The display on mine is off when no batteries are inserted. The backlight on my 808m however has died though.

Yes, you're absolutely correct and I missed that tidbit.

I still don't leave stuff plugged in, but that's a different issue.

Thanks for correcting me.

Chris

 

[Rosoku Chikara]

...What are the main things I need to be looking for when the refresh - analyze cycle is done?

Well, there really isn't much, I don't think. As I said, I don't even have my manual handy anymore. I just "use" my C9000 these days. But, let me start at the beginning for you. There are five things that you can do with your C9000 (I am not listing them in the same order as the selection order on the display of the C9000):

1) Charge

This function is pretty straight forward. Pop your cells in, and start charging. One thing: I have gotten in the habit of rotating all my cells, so that the labels all face the same way... (more than "a tad OCD"?) This may seem nutty, but it does seem to help make certain that all cells have a good connection (especially AAAs), and it would make it obvious if any of the cells were inserted backwards (in the unlikely event that you ever managed to get one inserted the wrong way).

As you know, if you simply "pop them in" and press enter, or do nothing, you will get a 1000mA charge by default. I believe this is perfectly fine for AAs. (It might be a little bit too high for some lower capacity AAAs... but, probably not.)

I now believe I was much too conservative on my charging rates, and I probably should have started using a higher rate. As you probably know, too low of a charging rate can be a problem. I think, due to its use of the final trickle charge, this is much less of an issue with the C9000 than on some other chargers. But, probably 600mA would be considered much too low for 2400mAh cells, so you should probably use something higher. I no longer watch over the charging process "like a hawk," but I have never experienced any sort of missed termination even at 600mA. So I guess, until I experience some problem, I will keep using it.

Anyway, I decided in the beginning to use only 600mA because I figured it would be extremely "gentle" on the cells, and I am almost never in need of a rapid charge. (I always have plenty of well-charged spares around.)

2) Discharge

This function is just as simple. When you need to discharge, pop in the cell and set to Discharge and hit enter. As I mentioned before, I use the default 500mA. And, I use it for both AA and AAA cells.

3) Cycle

So, the "Cycle" function simply takes whatever Charge and Discharge rates you specify when setting the "Cycle" function, and repeats them the number of times that you specify. I have forgotten the details, but I believe the C9000 also inserts an appropriate "Rest" period between cycles.

4) Break-In

As you know, this function simply charges your cells for 16 hours, twice (with rests and Discharge, in between). Total time can be 40 hours or more. The rate of charging depends on the capacity of the cell that you input. The only issue that I know of is what to do when your cell reads 2450mAh... Do you input 2400 or 2500? I went with 2500, and have kept that consistent over the years.

5) Analyze

So, after having written my own user manual :laughing:, I am finally getting to your actual question. I do not think there is all that much more to be said. This analysis function simply delivers the best (most accurate) capacity rating for your cell that the C9000 is capable of delivering. You set the Charge and Discharge rates that you have decided on above, and "let her rip." I really don't think that there is much "Refreshing" involved, despite the official name of this function. All it does is Recharge, Rest, Discharge, Rest, and Recharge. I think it is more about making certain that your cell(s) are all in relatively consistent shape (as far as charge/discharge status) prior to attempting to accurately measure capacity.

Others may disagree, but in my opinion 2-3 Cycles (or more), or a Break-In, or even a combination of those two functions are more likely to do more to actually refresh a poorly performing cell, despite the fact that Maha calls this function "Refresh & Analyze."

The only thing I do after the Analysis has been completed is record the cell capacities in my Excel spreadsheet. Here is an example of the capacity data for four packages of 4xAA cells:

ANALYZE	ANALYZE	ANALYZE	ANALYZE
2430 mAh	2419 mAh	2458 mAh	2454 mAh
2436 mAh	2411 mAh	2415 mAh	2428 mAh
2448 mAh	2424 mAh	2473 mAh	2449 mAh
2456 mAh	2417 mAh	2434 mAh	2474 mAh

Those 16 cells yielded the following "Matched Sets":

SET OF 4	SET OF 4	SET OF 3	SET OF 2	SET OF 2	SINGLE
2430 mAh	2419 mAh	2454 mAh	2474 mAh	2449 mAh	2436 mAh
2428 mAh	2415 mAh	2458 mAh	2473 mAh	2448 mAh
2424 mAh	2417 mAh	2456 mAh
2434 mAh	2411 mAh

 

[Mr Floppy]

I still don't leave stuff plugged in, but that's a different issue.

I know it's a different charger but the 808m was left on all the time. I don't know if that contributed to the backlight going but I try not to leave much plugged in unused as well.

 

[roadwarrior]

5) Analyze

So, after having written my own user manual :laughing:, I am finally getting to your actual question. I do not think there is all that much more to be said. This analysis function simply delivers the best (most accurate) capacity rating for your cell that the C9000 is capable of delivering. You set the Charge and Discharge rates that you have decided on above, and "let her rip." I really don't think that there is much "Refreshing" involved, despite the official name of this function. All it does is Recharge, Rest, Discharge, Rest, and Recharge. I think it is more about making certain that your cell(s) are all in relatively consistent shape (as far as charge/discharge status) prior to attempting to accurately measure capacity.

Others may disagree, but in my opinion 2-3 Cycles (or more), or a Break-In, or even a combination of those two functions are more likely to do more to actually refresh a poorly performing cell, despite the fact that Maha calls this function "Refresh & Analyze."

I do appreciate the detailed feedback!

I basically was trying to accomplish, what you stated in #5 Analyze. Mostly wanted to see if my dumb charger had induced any of the cells to perform poorly. I don't have many quads on hand right now to do a proper "break-in" on any of them yet. My device gets about 8-9 hours run time before it advises a low-battery alert, at which time I have to do a swap to avoid data loss or corruption of the SD card.

Once I get the other two quads I ordered, I will have 5 sets to rotate and keep charged. Out of the five three will be brand new and never used, the Duraloops, Eneloop Pros and the Powerexs.

My priority right now is to mainly try and recover or condition any mAh loss the 2 months of "dumb" charging may have induced on the Energizers or CORUNs.

Thanks again for the time you took to help me, I also do find it interesting to read how others "do business", one can never stop learning from others.

P.S.

One thing: I have gotten in the habit of rotating all my cells, so that the labels all face the same way... (more than "a tad OCD"?)

I did the same thing....LOL!

 

[Rosoku Chikara]

...P.S. I did the same thing....LOL!

"Great minds think alike..." and all that.

One other thing I did forget to mention: I am not entirely certain of this, but I have read several times on our forum that the C9000 flashes some kind of cell impedance or "internal resistance" value, once, and only once; and only very briefly when the cell is first placed into a slot. If you are interested, you may wish to look into that a bit more.

I think the one "serious" complaint that I have read about the C9000 is that it can refuse to charge high impedance cells that some other chargers will still charge. The C9000 simply shows "High" and refuses to do anything more.

In my case, I have decided not to worry about this issue at all. If and when I finally get an Eneloop that reads "High," I will simply recycle it on the spot. (Some people actually recycle their cells much sooner than that... at around 80% capacity, in some cases. But, I see no reason to do that, if it will still charge. But, if my C9000 ever refuses to charge it... its a goner!)

 

[MidnightDistortions]

Can't wait to start playing with this instrument, but being as I am a tad OCD, I want to make sure I play with it right. So I have a few questions I hoping you experts can help me with, with that said, please bear with me, if my questions seem dumb. I am a complete noob, who's only clue to date on these matters has come from the very knowledgeable folks on here that have taken the time to help me.

1. Is it okay to leave the Maha plugged in indefinitely , when I have no batteries inserted?

I usually do, but i also don't leave the the batteries sitting in the charger leaving the display on all the time, with that being said even if you left LSD cells in the C9000 overnight it won't harm the batteries, i generally don't do this all the time though.

2. I have the following quads I have been rotating out of my application (a radio scanner) for approximately 2 months, Energizer AA 2300mAh I purchased new out of the package and a quad of CORUN AA 2300mAh that came with my scanner. What should I do first with either on my Maha? If it matters, I was using the Energizer PRO model CHPRO to charge them prior to receiving my Maha.

Mentioned this in another thread on the C9000.

3. I have a quad of Duracell AA 2400mAh Ion Core, "Duraloops" brand new, still in the package unused I bought from Wally World yesterday. What should I do with them first?

I usually just choose the refresh analyze function (or i use the La Crosse BC1000 on it) and just to ensure they meet minimum spec. I only really run a break-in on non LSD cells and other ones that are underperforming.

P.S. I will gladly accept any and all feedback from anyone who owns or has owned the C9000, pertaining to new user advice, lessons learned, dos and don'ts, etc.... :thanks:

I would just make sure that the AAA cells are firmly put in, if the negative terminal doesn't push in the charger's negative terminal you won't get a good or any connection. Then just make sure the positive terminal is firmly pushed in. I had a bit of trouble with that when i first got the charger. And also here's a guideline on, internal resistance which will most likely show up on the charger as voltage when you first put in the cell. I would note this when you are putting in cells..

New cells - 1.4 v (or lower) 0% IR
5 year cells - about 1.8 v 50% IR
5+ year cells - 2.0v or higher 80-100% IR

The year is a rough guideline, so if you happen to have 5+ year old cells that are only about 1.5v or so that would be impressive but i would more likely pay attention when they reach about 1.8v as sometimes when cells are partially or 80% charged already they could be at 2.08v or higher you can always run a discharge on them to see. Fully discharged cells generally will show a lower IR than partially charged cells. If there's hardly any difference even when you discharge the cells (sometimes i've seen the IR go up on some older cells) your cell may not function as well, even if you can only get 80% (or higher) of the maximum capacity. The C9000 is a bit more hard on the cells so you'll see them underperforming when they have higher IR.

 

[roadwarrior]

I usually do, but i also don't leave the the batteries sitting in the charger leaving the display on all the time, with that being said even if you left LSD cells in the C9000 overnight it won't harm the batteries, i generally don't do this all the time though.



Mentioned this in another thread on the C9000.



I usually just choose the refresh analyze function (or i use the La Crosse BC1000 on it) and just to ensure they meet minimum spec. I only really run a break-in on non LSD cells and other ones that are underperforming.



I would just make sure that the AAA cells are firmly put in, if the negative terminal doesn't push in the charger's negative terminal you won't get a good or any connection. Then just make sure the positive terminal is firmly pushed in. I had a bit of trouble with that when i first got the charger. And also here's a guideline on, internal resistance which will most likely show up on the charger as voltage when you first put in the cell. I would note this when you are putting in cells..

New cells - 1.4 v (or lower) 0% IR
5 year cells - about 1.8 v 50% IR
5+ year cells - 2.0v or higher 80-100% IR

The year is a rough guideline, so if you happen to have 5+ year old cells that are only about 1.5v or so that would be impressive but i would more likely pay attention when they reach about 1.8v as sometimes when cells are partially or 80% charged already they could be at 2.08v or higher you can always run a discharge on them to see. Fully discharged cells generally will show a lower IR than partially charged cells. If there's hardly any difference even when you discharge the cells (sometimes i've seen the IR go up on some older cells) your cell may not function as well, even if you can only get 80% (or higher) of the maximum capacity. The C9000 is a bit more hard on the cells so you'll see them underperforming when they have higher IR.

Thanks for info, I will start keeping track of my voltages.

 

[Rosoku Chikara]

Thanks for info, I will start keeping track of my voltages.

I think this has been made clear, but just in case...

It is not actual voltage that is being discussed. It is a quick flash on the screen, when the cell is first inserted that shows a "voltage" number. That first flash of the "voltage" number is not the actual starting voltage of the cell prior to charging. It is, instead, a representation of the internal resistance of the cell. (Or at least, this is my understanding... I guess I am basing that largely on my believe that "cell impedence" or "internal resistance" would actually be measured in Ohms, not Volts. Somebody, please kindly correct me, if I am wrong.)

 

[ChrisGarrett]

I think this has been made clear, but just in case...

It is not actual voltage that is being discussed. It is a quick flash on the screen, when the cell is first inserted that shows a "voltage" number. That first flash of the "voltage" number is not the actual starting voltage of the cell prior to charging. It is, instead, a representation of the internal resistance of the cell. (Or at least, this is my understanding... I guess I am basing that largely on my believe that "cell impedence" or "internal resistance" would actually be measured in Ohms, not Volts. Somebody, please kindly correct me, if I am wrong.)

Yes, that's how I view it as well.

I have some Sanyo 2700 HDS batteries and they're pegging 2.65v+. A good value for me is anything under 1.55v.

Yikes.

Chris

 

[roadwarrior]

I think this has been made clear, but just in case...

It is not actual voltage that is being discussed. It is a quick flash on the screen, when the cell is first inserted that shows a "voltage" number. That first flash of the "voltage" number is not the actual starting voltage of the cell prior to charging. It is, instead, a representation of the internal resistance of the cell. (Or at least, this is my understanding... I guess I am basing that largely on my believe that "cell impedence" or "internal resistance" would actually be measured in Ohms, not Volts. Somebody, please kindly correct me, if I am wrong.)

Understood. I will look for that next time I insert cells. Thanks!

 

[roadwarrior]

Question....

For an application like my radio scanner, in which the when the batteries (4 AA) get to certain point (not completely dead) the scanner gives a low battery alert, at which time it is recommended to swap out the batteries to avoid data loss or SD card corruption.....so obviously at that point there is still a certain level of mAH still inside the batteries....So my question is....Should I discharge that small amount prior to charging? Or is it okay to go ahead and charge from that undrained state?

 

[Phlogiston]

The one time I'd want to be sure that a cell was completely discharged would be before a break-in cycle, because break-in shoves a certain amount of charge into the cell regardless of its current state of charge. That's unlikely to be healthy for a cell which already contains a significant charge.

For any other charging mode, I'd be fine with starting it on mostly but not completely depleted cells, because the automatic charge termination should take care of stopping the charge at the right time. The only difference is that charging would stop a little sooner than it would with completely depleted cells.

If you're curious, you could try a discharge cycle on your mostly depleted cells just after they come out of the scanner and see how much charge they actually have left.