What's latest version/firmware/model for Maha C9000?

[bmoorhouse]

I thought the first and second editions both provided the same primary charge before switching to the top-off charge. Is that not true?

Also, do you have any concern that the top-off charge will overcharge a battery in the first edition (and second, I believe) as the primary charge is so complete?

 

[Bones]

I thought the first and second editions both provided the same primary charge before switching to the top-off charge. Is that not true?
...

As set down in the post that's hyperlinked below, it's my understanding that there has only been the one revision to the MH-C9000's charging protocols:

http://www.candlepowerforums.com ... post2826876

...
Also, do you have any concern that the top-off charge will overcharge a battery in the first edition (and second, I believe) as the primary charge is so complete?

No, and it's actually because my first edition MH-C9000, which definitely utilizes Negative DeltaV as its primary charge termination protocol, applies the very same top-off charge as the revised edition.

This indicates to me that Maha were satisfied that even cells that have their charge terminated by this protocol can accept the additional charge.

Mr Happy explains it further in a post in another thread, which I've also hyperlinked:

http://www.candlepowerforums.com ... post2825364
.

 

[bmoorhouse]

Thank you, Bones. You have been very helpfull.

I originally bought the C9000 for two reasons. First, to ensure the batteries I use in my flashes are fully charged for max performance. And second, to treat them better than cheaper chargers in an effort to get the longest life out of them before needing replacement.

Obviously, for the second concern, the latest version of the C9000 would be better. I have a few questions, however, about the C9000 related to my first concern.

1. As my batteries drain, the flash output drops and the recycle time increases. Assuming a 93-95% charge with the latest C9000, will I see a corresponding 5-7% drop in performance if I don't use the two hour topoff charge or is battery performance not linear like that?

2. Is there any way to know if the C9000 cutoff due to max V or -dV? Some batteries due to manufacture, design, or age will never reach 1.47v. If they stopped due to -dV, than they are 100% already and the topoff charge is not only not necessary but might not be desired.

3. If the batteries do terminate for max V at 1.47 V, is there any way to know when the two-hour topoff charge is complete, ie when they are their closest to 100%?

Thanks for the help.

 

[Mr Happy]

Thank you, Bones. You have been very helpfull.

I originally bought the C9000 for two reasons. First, to ensure the batteries I use in my flashes are fully charged for max performance. And second, to treat them better than cheaper chargers in an effort to get the longest life out of them before needing replacement.

Obviously, for the second concern, the latest version of the C9000 would be better. I have a few questions, however, about the C9000 related to my first concern.

1. As my batteries drain, the flash output drops and the recycle time increases. Assuming a 93-95% charge with the latest C9000, will I see a corresponding 5-7% drop in performance if I don't use the two hour topoff charge or is battery performance not linear like that?

It is not linear. The flash recycle time is going to depend much more on the internal resistance of the cell than on the amount of charge. A 90% charged cell with low resistance will likely charge faster than a 100% charged cell with higher resistance. I doubt you would see much drop in performance until the batteries were down to 40% or less though.

2. Is there any way to know if the C9000 cutoff due to max V or -dV? Some batteries due to manufacture, design, or age will never reach 1.47v. If they stopped due to -dV, than they are 100% already and the topoff charge is not only not necessary but might not be desired.

There is not really a way to know unless you are familiar with your batteries. Some, like eneloops will always hit max V, and others will never hit it.

By the way, it is a misconception that batteries that stop on -dV are 100% charged at that point. How charged they are depends on many things, including charge rate and battery quality. They will certainly be more charged, but not necessarily fully charged. Also, the last 5% will not be seen unless you use the batteries immediately after charging.

3. If the batteries do terminate for max V at 1.47 V, is there any way to know when the two-hour topoff charge is complete, ie when they are their closest to 100%?

It depends on the batteries. For example with eneloops the voltage will rise to about 1.49 or 1.50 V during the top off, and then start to drop down to 1.47 V or less. If you watch the voltage you can tell.

Thanks for the help.

 

[NiOOH]

Thank you, Bones. You have been very helpfull.

I originally bought the C9000 for two reasons. First, to ensure the batteries I use in my flashes are fully charged for max performance. And second, to treat them better than cheaper chargers in an effort to get the longest life out of them before needing replacement.

Obviously, for the second concern, the latest version of the C9000 would be better. I have a few questions, however, about the C9000 related to my first concern.

2. Is there any way to know if the C9000 cutoff due to max V or -dV? Some batteries due to manufacture, design, or age will never reach 1.47v. If they stopped due to -dV, than they are 100% already and the topoff charge is not only not necessary but might not be desired.

3. If the batteries do terminate for max V at 1.47 V, is there any way to know when the two-hour topoff charge is complete, ie when they are their closest to 100%?

Thanks for the help.

If you watch the voltage during charging you will know. Also, cells that terminate on -dV reach higher temeperature. If you touch the cells shortly after the end of fast charge, you will know. In my experience, most cells of good quality reach 1.47 V and thus terminate on maxV. Some cheaper cells do not reach 1.47 V initially,but after a few charge-discharge cycles do.
Regarding the end of top-off, if you note the time when charging starts it may be calculated. Just read the charging time off the charger and add 2 hours. Another way is to listen to the charger. During top-off the charger makes a quiet but audiable noise like short beeps. After this the beeps become much shorter (maintanance charge).

 

[jalyst]

Hi all,

I was wondering if one of the users with lots of experience with this model...
Can advise which is the best Firmware/PCB revision around, & how I can find/buy it?

Apologies in advance if I'm supposed to post such questions here...
This thread seems dead, so maybe I should be posting in the aforementioned thread.

I will be setting-up my own dedicated thread soon...
It will pose a no. of questions RE 4-5 of the most prominent smart chargers around.

I've already done heaps of my own research...
But I'm still not 100% certain whether the C9000 is the most sophisticated option.

Hence I'm seeking some more detailed comparative analysis.
But that will be for another thread....

Thank-you.

 

[SilverFox]

Hello Jalyst,

Welcome to CPF.

The original release of the C9000 had some problems with some cells. Maha made a revision and all the units after that have done very well.

You may be able to find a place to purchase a unit by reviewing the information here.

Tom

 

[jalyst]

Hi Tom, thanks for adding your thoughts.

Yes I'm aware of the problems earlier & subsequent fixes.
But there's been no subtle improvements to fw/pcb since, that users discuss etc?

In case some of the much older revisions are still floating around...
Which particular revision/s do I want to avoid?

Thank-you.

 

[45/70]

Yes I'm aware of the problems earlier & subsequent fixes.
But there's been no subtle improvements to fw/pcb since, that users discuss etc?

In case some of the much older revisions are still floating around...
Which particular revision/s do I want to avoid?

Hi jalyst. There has been only one major revision of the C9000 that I'm aware of. That revision happened some years ago. Since then, there may have been some very minor changes in the C9000 charger, but I would not necessarily call them "revisions", per se.

There seems to be a common misunderstanding, as of late, that the "0x0xx" date of manufacture codes represent updated revisions of the C9000 charger. They do not. This "code" is merely the date code, which only represents the actual date of manufacture of that particular charger, and has nothing to do with firmware revisions.

Dave

 

[jalyst]

Thanks for the input Dave, tis appreciated.

Hi jalyst. There has been only one major revision of the C9000 that I'm aware of. That revision happened some years ago.

Yes I recall reading snippets about this major revision & the problems that predated it, still trying to find the original/main thread/s.

Since then, there may have been some very minor changes in the C9000 charger, but I would not necessarily call them "revisions", per se.

What changes were involved, are there any threads devoted to the discussion of this?

There seems to be a common misunderstanding, as of late, that the "0x0xx" date of manufacture codes represent updated revisions of the C9000 charger. They do not. This "code" is merely the date code, which only represents the actual date of manufacture of that particular charger, and has nothing to do with firmware revisions.

I see, so if I get one with a recent manufacture date (say 2011)...
Then I can be certain I've got one which incorporates that major revision, & subsequent minor revisions.

Do you know of any retailers that present the manufacture date of the C9000 they're selling? (I'm in Australia)

Thank-you.

 

[jalyst]

45/70 or anyone?
Sorry for bumping so soon, extremely strapped for time lately.
Thank-you!

*edit*
I've now started my own dedicated thread here

 

[45/70]

Yes I recall reading snippets about this major revision & the problems that predated it, still trying to find the original/main thread/s.

Hi jalyst. I see you've already found one of the C9000 threads. There is at least one other main one that is similar, maybe more. As VidPro suggested in one of the other threads, just do a search using the "CPF only" Google search and you should be able to find them.

What changes were involved, are there any threads devoted to the discussion of this?

As for the minor changes that have occurred that I said I wouldn't call actual "revisions", since the first major revision, the only one I can think of at the moment is that the AAA negative contacts have been slightly redesigned two or three times. As I said, I don't really qualify this as a "revision". If there were any other changes, they were just as subtle, and mentioned in the main C9000 threads.

I see, so if I get one with a recent manufacture date (say 2011)...
Then I can be certain I've got one which incorporates that major revision, & subsequent minor revisions.

You would have to go back at least four years to find one of the original unrevised C9000's. I once had a 0F0xx. These were really no different than the 0H0FA, or the 0I0IA that I now have, excepting the AAA negative contacts. I seriously doubt, as popular as these chargers are, that any retailer would have any stock of the original C9000's. It is interesting to note that some people actually prefer the original C9000, as it supports cells with a capacity of up to 20,000 mAh in all modes, compared to the revised version's 4000mAh maximum. Also note that the online C9000 manual, and most of the included manuals up to a year or so ago anyway, apply only to the original unrevised C9000's. These manuals do not address the effects of the major revision that occurred earlier on, unfortunately.

Do you know of any retailers that present the manufacture date of the C9000 they're selling? (I'm in Australia)

As I said before, I doubt that any retailers here, or down under, still have any of the original C9000's in stock. It's been a long time since they were around.

Dave

 

[jalyst]

If there were any other changes, they were just as subtle, and mentioned in the main C9000 threads.

Bummer, I was hoping there's a thread focusing only on revisions & their improvements -if any.
I guess I'll just have to find the dozens of individual threads, subscribe to, & read them all!?!

Anyway I'll make sure I get a K0?0?....
Then I can be sure that all the tiny revisions done from 2006-2010 will be incorporated!
Including any minor regressions if any, "touch wood!" :|

It is interesting to note that some people actually prefer the original C9000, as it supports cells with a capacity of up to 20,000 mAh in all modes, compared to the revised version's 4000mAh maximum.

Sux that they removed that from newer revisions, obviously a cost/quality cutting exercise!?
Supporting cells with a capacity up to 20k mAh, why is this a valuable feature for some?
If I were to obtain one of the original c9000's, I'd have to put up with it's other issues, do they outweigh this lost feature?

Also note that the online C9000 manual, and most of the included manuals up to a year or so ago anyway, apply only to the original unrevised C9000's. These manuals do not address the effects of the major revision that occurred earlier on, unfortunately.

Why does that matter?

As I said before, I doubt that any retailers here or down under, still have any of the original C9000's in stock. It's been a long time since they were around.

Yes but it'd still be nice to know manufacturing dates/codes to avoid, just in case there's still some floating around!

 

[jalyst]

45/70 or anyone? ^ Thank-you!

 

[SilverFox]

Hello Jalyst,

One of the best features of the C9000 is the ability to do a Break In that closely approximates the same test that the battery manufacturers use for determining the capacity of their cells. Keep in mind that cells that are re-labeled can state any capacity they think will sell, but if you can get back to the original manufacturers data sheet you can find what the capacity of the cells actually tested at. Since many times there is no access to the data sheet, and often the capacities are listed as "optimistic," this feature allows you to see where you stand with a particular brand of cells.

The original C9000 had a timer set to allow you to do a break in on sub C, C, and D sized cells. You would have to come up with an adapter to do this, but it would be a great feature to have. This is where the 20000 mAh limit came from.

Unfortunately, many people try to use cells that are marginal. One of the main problems with marginal cells is that they don't give a clean -dV indication. If the charger is depending upon the -dV signal to terminate the charge, and it doesn't get it, it just continues to charge the cell. With a maximum charge current of 2000 mA, you can generate a lot of heat in the cell if the termination is missed.

This happened with the original C9000. In order to correct this, Maha did two things. The first was to terminate the charge on -dV, or on reaching a maximum voltage of 1.47 volts. The other was to drop the maximum charge timer to 4000 mAh. This way it is nearly impossible to overcharge a cell.

The C9000 offers a wide variety of charging rates. This gives you lots of opportunity to screw up by choosing a rate that is not suitable for the termination used by the charger. The change "dumbed" down the charger so you can use any charge rate and not run into problems... most of the time. It is not unusual to have chargers miss terminations. Most chargers don't have the capability to quickly cook your cells, so when they miss the termination, they just continue charging until the timer times out and your cells only suffer mild abuse. Some of the charging rates that you can select with the original C9000 would be fine for charging, but if the termination was missed, the heat generated would melt the wrappers off of the cells.

While this mostly occurred with marginal cells, there were a couple of times when it happened with quality cells as well. Since this revision there have only been a couple of reports of missed terminations, and no reports of melting cell wrappers.

I have two units that are in constant use and I am very pleased with their performance. One is a OF and the other is a OG. Since there hasn't been any changes, I would expect your OK unit to work well.

The OF was the original unit, but mine was modified to incorporate the change and I was a beta tester of the unit after the change in termination. I may have the only OF unit that has the modification, but I don't know that for sure.

It will be interesting to see how your older (perhaps marginal) cells do in the C9000. Keep us posted.

Tom

 

[45/70]

The OF was the original unit, but mine was modified to incorporate the change and I was a beta tester of the unit after the change in termination. I may have the only OF unit that has the modification, but I don't know that for sure.

Hi Tom. I believe I originally had a 0F0xx unit that was the revised version. I don't remember the last two digits, but am pretty sure it was a 0F0. Maybe it was one of the last 0F's, but it worked identically to my 0H and 0I units. Then again, maybe it was a 0G0xx and I remember incorrectly. I sent it back to Maha because the display crapped out under warranty, so I don't have it anymore.

jalyst, I think Tom covered all the modifications that were done during the first revision, but one. Tom, you forgot about the 50 Watt HID back light for the LCD display! And jalyst, it is important to note that all of these modifications happened at the same time, ie, they didn't happen over a period of time but rather all in the same revision.

EDIT: After looking around a bit, I found the post where I mentioned my LCD display had gone bad. I also mentioned the revision of the charger. It was actually a 0G0IA. My mistake!:candle:

Dave

 

[Mikl1984]

After visible modifications in FW during last 5 years we saw 9!!! revisions of PCB for example
Maha-MH-C9000-Disassembled

 

[45/70]

Oops! I was wrong. The first C9000 I had was an 0G0IA. I edited my previous post.

Dave

 

[SilverFox]

Hello Mikl1984,

So, in function what is the difference between version 8 and version 9?

Tom

 

[Mr Happy]

So, in function what is the difference between version 8 and version 9?

I think it's difficult to figure this out without having both examples in hand and doing a detailed analysis of the differences. It is not unusual for circuit boards to go through revisions during production, and there might not necessarily be any functional differences implied. It might be, for instance, that one or two components had be swapped out for equivalents from a different source due to availability. However, I do recall that the shape of the negative battery clip for AAA cells was changed at some point, and this might be one reason for a revision.