So .. to summarize ... MAHA C9000

[LiteTheWay]

The very long (and mostly informative) thread earlier makes it difficult to follow the issues. Do those who have done all the testing think this is a good charger PROVIDED I can get an 'improved' or 'later' version?

 

[Power Me Up]

Yes, I would recommend it.

 

[wptski]

I think that this charger was looked at more closely because of the BC900 problems. I've been graphing tempertures on different cells for several weeks and hope to post them when time allows. I still get cells over 140F charging at 2A but some of it if not all of it is the cells themselves! Very confusing...

 

[SilverFox]

Hello 7histology,

Highly recommended.

If you have "crap" cells, or your cells have "issues," stay away from 2 amp charging. You will know if you have problems with your cells because they will heat up.

There is a lot of controversy over cell temperatures during charging. Universally, 140 F is too hot. I prefer my cells to be at around 125 F at the end of a charge, others think that is too hot, and prefer them to be in the 90 - 100 F range. Cell temperature should not exceed 95 F during the Break-In or 0.1C charging, when the room temperature is between 60 - 77 F. Cell temperatures will be higher with faster charging rates.

As far as I know, no one has had a missed termination with the improved C9000, at any charge rate, using any cells.

Refresh/Analyze works fine.

The Break-In function is great, but it will sober you to the inflated claims on the labels.

Discharge seems to be functioning properly.

There seems to be a display "issue" when using the cycle function. The cycle is properly done, but the displayed information for the cycles end up with repeating or missing digits. You get a ballpark idea of what the capacity for the cycle was, but not the exact amount. For example, if your cell had 1568 mAh, the display may show 1515. If your cell had 543 mAh, the display may show 505.

All in all, still highly recommended.

Tom

 

[Power Me Up]

As far as I know, no one has had a missed termination with the improved C9000, at any charge rate, using any cells.

Actually, I posted here about some cells that missed termination in the improved version of the C9000.

I still recommend the charger though - I'm not aware of anything that is better that is currently on the market.

There seems to be a display "issue" when using the cycle function. The cycle is properly done, but the displayed information for the cycles end up with repeating or missing digits. You get a ballpark idea of what the capacity for the cycle was, but not the exact amount. For example, if your cell had 1568 mAh, the display may show 1515. If your cell had 543 mAh, the display may show 505.

In the example case of a real measured capacity of 543 mAh, the displayed capacity is shown as "5 5" This isn't a really major issue since it only occurs for first cycle when you're using that mode and I don't use that mode too much anyway. It's more of an annoyance, but it still should have been fixed with the improved version...

 

[LiteTheWay]

Great. Thanks to both SilverFox and LMU. I'll order one now that I have this advice and that I know where to to get it here in Oz.

The Oz distributor says that as far as MAHA has communicated with him, there is no difference between the OG* and OF* batches and BOTH as supplied to Oz are 'improved' versions ..... but I think I'll get the one from the OF* batch anyway which the Oz supplier (Servaas Products in Melbourne) is prepared to humor me on.

 

[Power Me Up]

You actually want the 0G0B01 version. The 0F version is the original.

Although I can't say with absolute certainty that they don't have improved versions with the 0F label on the back, I can't think of any reason why they would - it would only make sense for the improved version to have a different label...

I've read at least one post of someone being told directly by Maha that there wasn't any such thing as a new improved version and that they were all the same - I can definitely say that there are at least 2 different versions because I have both an old and a new version here...

 

[LiteTheWay]

er yeh ... I meant the OG* version (F comes before G.... duh)

 

[alexanderino]

Hi 7histology,

before I bought the MH-C9000 from Servaas, Jeff confirmed they have the 0G0B01 in stock. Received mine on Thursday, and having lots of fun with it. Hope you do, too.

A big thanks to Tom (SilverFox) for his enlightening [heh] posts and research. They went a long way in my decision to get it.

Cheers,

Jason

 

[EngrPaul]

I'm very happy with mine now. Hopefully they come out with a datalogging charger next to hook up to a PC. That would be pure bliss.

 

[SilverFox]

Hello Power Me Up,

Somehow I missed your post. I figure no charger is perfect and it was just a matter of time before someone found some cells that would miss termination.

I had some "issues" with the original C9000 with some NiCd cells. However, when I tried to reproduce it a second time, I was unable to. Are you able to get the C9000 to miss the termination during subsequent charges of those NiCd cells?

Tom

 

[Power Me Up]

Hello Power Me Up,

Somehow I missed your post.

No problem!

I figure no charger is perfect and it was just a matter of time before someone found some cells that would miss termination.

I see no reason why a charger couldn't be made that would never fail to terminate - late terminations maybe, but failing to terminate and continuing to charger forever or until a timer runs out shouldn't be acceptable IMHO...

I had some "issues" with the original C9000 with some NiCd cells.

I've seen missed terminations with NiMH cells on my "original" C9000 as well (I've got both an original and an improved version)

Yes, they were "crappy" cells!

However, when I tried to reproduce it a second time, I was unable to. Are you able to get the C9000 to miss the termination during subsequent charges of those NiCd cells?

I'll give it another go once I've discharged the cells again.

 

[X_Marine]

I'm very happy with mine now. Hopefully they come out with a datalogging charger next to hook up to a PC. That would be pure bliss.

I'll second that and back it up with PP.. lol
X

 

[LiteTheWay]

yep - really looking forward to mine too. definitely looks like the one to have.

 

[digitor]

I have the "original version" - whatever that means - according to Maha there's no difference! Mine was from the first batch to arrive in Oz in early Feb., and has the 0F* part number.

It's never missed a termination on any of my cells (I've only got four different brands of various ages) at any charge rate, even when I've tried using low rates of 0.1C, which is not recommended. The temperature at termination when charging at 2A seems about the same as my C801D, but I normally charge at 1A on both chargers anyway.

I've not tried to duplicate the display bug yet, perhaps I'll give it a go this week and see what happens.

I'm very happy with the performance of this charger, it's enabled me to weed out my problem cells, and has even recovered a few for me using the break-in mode.

Cheers

 

[xiaowenzu]

I read that it's best to let the charger automatically do it's job, although it's going to be slower.

With my new Eneloops I'd like them to have longevity, and it's important that we charge our batteries slowly.. (10-12 hours for 2100mah)

I like the fact that Maha 9000 caters for the profressional AND casual user. For me I like things automatic. I just stick my depleted batts in the slots and 12 hours later....viola! I'm done.

 

[digitor]

The default rate on the C9000 is 1A - so your cells will be ready in a lot less than 12 hours! Charging at 0.1C is not recommended.

Cheers

 

[xiaowenzu]

The default rate on the C9000 is 1A - so your cells will be ready in a lot less than 12 hours! Charging at 0.1C is not recommended.

Cheers

I think 4 - 5hrs is a good time - not too slow and not too quick. Otherwise it will make the battery very warm, which is not good.

 

[SilverFox]

Hello Xiaowenzu,

The battery manufacturers recommend a minimum of a 2 hour charge. Their reason is that at lower charge rates, the end of charge termination signal can be very slight and difficult for the charger to pick up.

The charging rate comes down to how your charger works, and the condition of your cells. "Crap" cells get hotter then cells in excellent condition at any charge rate. If you charger utilizes other methods than -dV for termination, you may be able to charge at different rates and still have reasonable charge termination.

I know that hot is 140 F and normal is around 90 - 110 F, what is your definition of "very warm?"

Tom

 

[xiaowenzu]

Thanks for the enlightenment. My definition of very warm is over 100 F. Anything above that is too warm. I prefer the temp at end of charge about 80-90 F. This is why I like slow charging rate.. it's much kinder for the cells. I know the best chargers like Maha 9000c enable you to select the charge current. If possilbe I'd choose the one which charges in 12 hours.. the batteries would be cool!

I know that hot is 140 F and normal is around 90 - 110 F, what is your definition of "very warm?"

Tom