TakeTheActive
Enlightened
There are several interesting / informative LINKs in my Sig Line LINKs discussing:
- Crystals
- Charging Rates
- Storage Box Queens
Maha MH-C9000 SUPPORT / FAQ - continuation
- Thread starter willchueh
- Start date
TakeTheActive
Enlightened
No. And I just edited my earlier post to make it clearer.
I'm saying that NEWER cells with LOW Internal Resistance can supply mA at a higher rate PER hour than OLDER cells with HIGH Internal Resistance (i.e. our 'non-vibrant' *CRAP* cells).
You may be able to Discharge a *CRAP* cell @ 100mA (and lower) and get 80% of it's original Capacity but raising the rate to 1000mA (and higher) may drop the available Capacity to 60%.
TakeTheActive
Enlightened
Sounds like the current La Crosse BC700/BC900/BC9009 design... :thinking:
Combine that with the lack of a REST period between Charge and Discharge and you get the 'artifically' higher Capacity readings from the La Crosse chargers compared to the new-style / current Maha MH-C9000.
Question(s) to owners of BOTH old-style and new-style MH-C9000s (and possibly one of the La Crosse models):
- Do you see consistently higher Capacity readings from your old-style C9000 compared to your new-style?
. - If you also have a La Crosse, how close are the old-style C9000 Capacity readings to the La Crosse?
Mr Happy
Flashlight Enthusiast
Unfortunately I think you just made things less clear. The phrase "supply mA at a higher rate per hour" really has no meaning. There is no such thing as mA per hour.
It works like this: a rate of 1000 mAh per hour (1 coulomb per second) is equal to a current of 1000 mA. So batteries with a lower internal resistance can supply mAh (charge) at a higher rate than batteries with a higher internal resistance for the same voltage drop. Which simply translates to saying batteries with a lower internal resistance can supply higher currents than batteries with higher internal resistance.
In reality, batteries with a higher internal resistance do appear to have a lower capacity when discharged at a higher rate, which is what I think you are getting at. The lower capacity is because the battery reaches the end point voltage more quickly where it is not able to continue discharging energy in a useful way. So you get less useful energy out of the battery at the higher discharge rate.
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TorchBoy
Flashlight Enthusiast
TTA, if you're talking about a rate it would be "something per time" anyway. And capacity per hour is current...
45/70
Flashlight Enthusiast
It is much faster. It doesn't accomplish any more than is needed. The large crystals still have their charge. You only need to charge up the smaller particles a bit, to prevent undervolting the cell when discharging.
As I remember, it has to do with the heat generated within the cell (not necessarily felt on the outside surface). As the compounds in the cell start churning around at high charge rates, the separator can be punctured or torn.
This is true. See comment above.
I want to add that while the BC-900 does have a few advantages in some areas, my AA/AAA charger arsenal consists of three C-9000's and one BC-900. :)
45/70
Flashlight Enthusiast
As I understand it, yes, large crystalline formations are caused by slow charging. The question is, how slow? My research on this has always been somewhat inconclusive. It would seem most agree that a "standard charge" of 0.1C does not promote large crystalline formation (nor does it alleviate the problem). I've even come to the conclusion that 0.05C is OK. Lower than that, seems to be where they form.
I also think that "self discharge" promotes large crystal formation as, in my experience, these cells seem to show the most prominent signs. It could be though, that a damaged separator is playing a bigger part here. Not sure.
Dave
I found some old "Bossman" and "DynaCharge" AA's purchased in the early 90's in a drawer and the MAHA seems to be able to charge them (i.e. no HIGH displayed) but the batteries themselves have no indication of their capacity written anywhere on them
What Discharge/Charge rate should I use when using the Break In or any of the other modes if I don't know their capacity?
What Discharge/Charge rate should I use when using the Break In or any of the other modes if I don't know their capacity?
TakeTheActive
Enlightened
- I'd start out with a BREAK-IN @ 1500mA
- Then, I'd take the average Capacity reported rounded up to the next 100 and call that 'C'.
- Depending on the amount of built-up Internal Resistance, I'd then CHARGE @ 0.5-0.67C and DISCHARGE @ 0.2C a few times and see what results I'd get.
My current cheap-o charger is started to act up so I've been looking at a c9000 and have a few questions.
Is it possible to select a 2A charging rate for all 4 cells? Or only for 1or2 cells?
Is there any way to tell the firmware without opening the box?
Has anyone found that companies have old stock? Has anyone who recently bought one had old firmware?
Is it possible to select a 2A charging rate for all 4 cells? Or only for 1or2 cells?
Is there any way to tell the firmware without opening the box?
Has anyone found that companies have old stock? Has anyone who recently bought one had old firmware?
Codeman
Flashlight Enthusiast
- Joined
- Nov 26, 2004
- Messages
- 2,690
The C9000 allows individual settings on each of the 4 stations. You could charge at 1A in one, 2A in another, a 0.5A discharge in the third, and be doing a refresh in the fourth slot, all at the same time.
I don't think firmware versions are on the outside, but unless things have changed, they come in a cardboard box with a flap top, so you can return it in pristine condition if you want. Thomas Distributing is good to deal with, and they probably have a good turnover of their stock.
I don't think firmware versions are on the outside, but unless things have changed, they come in a cardboard box with a flap top, so you can return it in pristine condition if you want. Thomas Distributing is good to deal with, and they probably have a good turnover of their stock.
Bones
Enlightened
As Codeman has indicated, whatever it will do with one cell, the MH-C9000 it will do with 2, 3 and/or 4. Just consider it four 1 bay chargers with respect to applying its full range of settings to individual cells.
There were only three modifications noted, and the last was some time ago. The first altered it's charge termination process. The second rectified what was known as the repeating digit error; which was essentially an error reporting the results of one bay on the second cyle when in the cycle mode. The third ramped up the already bright backlight of the display.
Perhaps someone else can confirm this, but insofar as I can recall, if you receive one with the code on the label beginning after 0G (zero G), ie: 0H, you should be okay.
I've been doing some research on the net and the information out there has got me a little confused about maintaining those bateries that are in in 'long term' storage.
So to clarify:
For batteries that aren't used (or aren't going to be used) in a long time, say over a year, we should take these out and run them though the Refresh/Analyze mode on the c9000 every 6 months. Correct?
Do we then store these with the full charge that results? There are references that they should be stored with a partial charge (how to easily acheive this on the Maha?)
Does the above process apply to both Nimh and Nicds?
So to clarify:
For batteries that aren't used (or aren't going to be used) in a long time, say over a year, we should take these out and run them though the Refresh/Analyze mode on the c9000 every 6 months. Correct?
Do we then store these with the full charge that results? There are references that they should be stored with a partial charge (how to easily acheive this on the Maha?)
Does the above process apply to both Nimh and Nicds?
Anders
Enlightened
Hello Bobor.
Read this post by Silverfox.
"Storing cells is a balancing act. The best way to store cells is to have them in a discharged condition and stored at around 40 F. At cooler temperatures, the chemical activity within the cell is greatly reduced, but does not completely stop. You can’t just leave them, or they will continue to run completely down resulting in an over discharged state that damages the cell. When you store cells in a discharged state, you need to do a charge/discharge cycle every 30 days to keep the chemistry active. If you want to store for longer periods of time, you can discharge the cells, then put a partial charge back on them."
A partial charge can be done by first discharging and then charging 20-25% or so, then removed.
Anders
Read this post by Silverfox.
"Storing cells is a balancing act. The best way to store cells is to have them in a discharged condition and stored at around 40 F. At cooler temperatures, the chemical activity within the cell is greatly reduced, but does not completely stop. You can’t just leave them, or they will continue to run completely down resulting in an over discharged state that damages the cell. When you store cells in a discharged state, you need to do a charge/discharge cycle every 30 days to keep the chemistry active. If you want to store for longer periods of time, you can discharge the cells, then put a partial charge back on them."
A partial charge can be done by first discharging and then charging 20-25% or so, then removed.
Anders
TakeTheActive
Enlightened
Click on my Sig Line LINK and read about 'Storage Box Queens'.
to TakeTheActive --
:wow:
That is a wonderful information resource you've compiled !
Thank you for your time, effort, and dedication.
:goodjob::thanks:
_
:wow:
That is a wonderful information resource you've compiled !
Thank you for your time, effort, and dedication.
:goodjob::thanks:
_
FUNWITHPOWER
Newly Enlightened
- Joined
- Aug 26, 2009
- Messages
- 8
Ok I Have a couple of questions which you guys will probably answer with no problem, and for my first one, I have the MH-C9000 and Brand New eneloop batts and it seems it is best to discharge them first then break-in, but I wanted to know if just putting them in the device that they were bought for to do the discharging and (whatever that may be, RC transmitter most likely in my case) then do the break-in on the MH-C9000, or is it best to do the discharge with the MH-C9000??? (Better for the longevity and performance of the batts) My next question is, in discharge mode does it automatically start a top off charge and trickle charge after discharge in discharge mode has finished, because that is what my manual seems to say, but it seems I have read in other places that it does not charge... last question is once the MH-C900 is "DONE" mode, can all variables be viewed (capacity, voltage, time, and current,), or just the capacity, because again the manual makes it sound capacity is all that can be viewed once the program is finished??
Thanks a lot guys!!!
Thanks a lot guys!!!
pobox1475
Enlightened
I would use C9000. Transmitter will take a lot longer.
In my experience, no.
I will leave this for an expert to answer. I usually just pull e'm off assuming charger has don it's best. I would like to know what info is worth noting to be aware of the cells condition.
pobox1475
Enlightened
Oh, yea FUNWITHPOWER :welcome:.......................................
PEU
Flashlight Enthusiast
I purchased a C9000 at Thomas Distributing on 4/30/2007 it worked great for a while but around mid 2008 the rightmost slot began to malfunction causing the charger to self reset.
Since then I solved it by putting a duracell (non rechargeable) battery in it so it detects is high impedance and does not use that slot. The other 3 work OK.
If I were in USA I would send the unit back for a replacement, but since Im in Argentina, TD told me (on febb/2009) that they do not pay for shipping overseas for warranty replacements.
I would like to know if someone knows how to fix this.
or should I contact Maha directly to check if they assume the back/forth shipping?
Ideas?
Thanks
Pablo
Since then I solved it by putting a duracell (non rechargeable) battery in it so it detects is high impedance and does not use that slot. The other 3 work OK.
If I were in USA I would send the unit back for a replacement, but since Im in Argentina, TD told me (on febb/2009) that they do not pay for shipping overseas for warranty replacements.
I would like to know if someone knows how to fix this.
or should I contact Maha directly to check if they assume the back/forth shipping?
Ideas?
Thanks
Pablo
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