Maha MH-C9000 Wizard One Charger

SilverFox

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Wow!!! This is the charger/analyzer we have been hoping for.

Maha has stepped up to the line with a charger that offers a wide variety of charge rates, and also offers cycling, refreshing, and discharging at a wide variety of rates. It directly supports AA and AAA sized batteries, and charges/discharges/analyzes each of its four slots independently. The large lighted display is easy to read and gives you the information for each slot, one slot at a time. The buttons are well spaced and have a good "feel" to them. There is ample space between the cells so it is easy to remove and replace a cell, even if it is in a middle slot. The large backlit LCD display and the extra space between cells make the C9000 larger than most other four cell chargers, but it also has a more complete "feature set" than any other consumer charger on the market. It is suitable for charging NiMh and NiCd cells, including the new "low self discharge rate" cells.

One of the most important and beneficial features of the C9000 is the Break-In mode. Battery manufacturers rate their battery capacity and cycle life using a "standard" charge and a "standard discharge." The C9000's Break-In mode allows you to compare your batteries performance to what they are supposed to be. This allows you to know the condition of your batteries, and to compare various brands of batteries.

Sometimes batteries that have been abused or left in storage for an extended period of time can be brought back to life by a Break-In cycle. It doesn't always work, but since it is an automatic function on the C9000, it's worth a try.

Well, it's not completely automated. It's best to start with a discharge battery, so you may have to do a discharge first and then run the Break-In. Most cells should be able to handle the low charge rate of the Break-In mode without problems, but some cells have a higher internal resistance and they tend to heat up a lot when overcharged. Starting with a discharged cell eliminates the overcharge heating.

Keep in mind that the "standard" charge involves charging a cell at rate equal to one tenth of its labeled capacity for 16 hours. In the Break-In mode, this "standard" charge is followed by a one hour rest period, then the cell is discharged over five hours. After another rest period, another "standard" charge is done on the cell. Doing the math we come up with a 16 hour charge + 1 hour rest + 5 hour discharge + 1 hour rest + 16 hour charge = 39 hours.

39 hours seems like a long time to tie up your charger, but your cells will love you for it. Since it requires no input from you, other than selecting the mAh capacity of your cell when you start, you can just set it and leave it.

Those who can figure out a way to charge C and D sized cells external of the C9000 can use the Break-In mode for those cells as well. The maximum capacity for the C9000 in Break-In mode is 20000 mAh. Understand that these larger capacity cells will take longer to complete the Break-In than AA cells.

The alternative is to do several cycles. The C9000 allows you to program up to 12 cycles and allows you to set the charge and discharge rates for the cycling. It also stores the capacity data so you can review it and see what effect cycling is having. The default charge rate is 1000 mA and the default discharge rate is 500 mA in Cycle mode.

These features alone make it worth having this charger, but there is more…

The C9000 has a discharge only mode.

Have you ever wondered how much capacity you loose with your cells sitting on the shelf for a week or so? It is often widely stated that NiMh cells will loose almost all of their capacity in a very short time, however with the discharge mode of the C9000 you can put those reports to bed and know that is not the case. With the introduction of the new low self discharge rate batteries like the Sanyo Eneloop cells, you can also check to see if they are holding up to their claims. You can also determine how much of an improvement a higher capacity battery offers.

You can even check out the various brands of Alkaline cells to see which offers the highest capacity for the discharge rate you are interested in. The C9000 will not charge Alkaline cells, but it does allow you to do a discharge on them. Ever wonder how much better a Lithium primary cell is than an Alkaline cell? Now you can check it out for yourself.

The discharge mode defaults at 500 mA, but allows you to select a discharge rate from 100 mA to 1000 mA, in 100 mA steps. It continues until the cell reaches 0.9 volts and the display shows the capacity in mAh, the voltage of the cell, and the time involved with the discharge. This information is displayed until the cell is removed.

In multi cell applications, your device will stop working when the lowest capacity cell runs out. To get the best performance in multi cell applications, you need to match your cells on capacity. This way they all run out at the same time. The discharge mode of the C9000 allows you to do this.

Make sure you also get the 12 volt adaptor cord for the C9000. In many parts of the world there are times when an emergency occurs and the power goes out. During an extended power outage the C9000's ability to operate from 12 volts gives you the ability to recharge batteries when the main power is out.

The AC adapter for the C9000 works worldwide accepting 100-240 volts 50/60 Hz input.

Now that we have worked our way through all of the "bonus" features of this charger, let's take a look at how it charges.

To charge your batteries, insert them in the charger and take them out when "Done" is displayed.

If you are interested in a "fuller" charge, wait two hours after "Done" for the top off charge to complete.

That's it.



Can it really be that simple? YES!!!



As cells age their internal resistance increases. The C9000 checks for this and will display "HIGH" if the internal resistance is increased to the point that it is not healthy enough for high rate charging.

If you get the "HIGH" message, recycle the cell and move on.

Now if great grandfather gave you that cell and you just can't stand to part with it, there are a few things you can do. Hold it in your hand to warm it up. Internal resistance goes down with heat. A discharge at a higher rate will also warm the cell up. If that does not work, you will have to use a charger that does not check for internal resistance, but don't expect to get peak performance from it. If it does start to charge, do a Break-In on it and explain to great grandfather that this battery may die before he does…

The C9000 has a default charge rate of 1000 mA. This charge rate works great for all AA cells and also is well suited for AAA cells. It may be a little high for some of the older low capacity (600 mAh) AAA cells, but if the cell is in good condition, it will do fine at the default rate.

If you don't like the default settings, and think you know something about battery charging, the C9000 allows you to select a charging rate from 200 mA up to 2000 mA in 100 mA steps. The NiMh battery manufacturers recommend charging at a 0.5C to 1.0C charge rate to insure a strong "end of charge" signal. C refers to the labeled capacity of the battery. If we had a 2000 mAh battery, a 0.5C charging rate would be 1000 mA, and a 1C charging rate would be 2000 mA.

So, what happens if you want to charge everything at 200 mA?

Well, first of all, it takes longer, and secondly, the end of charge signal may be too weak for the charger to recognize it and terminate the charge. This will result in overcharging the cell. The C9000 will "time out" at 4000 mAh, but it is probably better to set a timer and manually check to see if the charger missed the termination signal. If it did, you can manually shut it off. I have charged a wide variety of brands and capacities of both AA and AAA cells at 200 mA and have not had a missed termination, but my sample is too small to make a broad statement. Usually the C9000 will properly terminate, but I am sure there will be some cases where it will continue to charge at this low rate until it "times out."

At the other end of the spectrum is charging everything at 2000 mA. When charging four AA cells at 2000 mA, the C9000 heats up. This heat is radiated to the cells that are charging, and they heat up as well. The amount the cells heat up is dependent on their internal resistance and general condition.

Here are some actual test results while charging 4 cells at 2000 mA:

AAA 850 mAh cells got up to 118 F. These cells were not in very good condition.
AAA 900 mAh cells got up to 115 F. These were in pretty good condition.
AAA 700 mAh cells got up to 112 F. These are old, well used cells.
AA 2300 mAh cells got up to 130 F. These are well used cells that have a slightly increased internal resistance.
AA 1800 mAh cells got up to 112 F. These cells are designed for high current and have very low internal resistance.
AA 2500 mAh cells got up to 125 F. These are new cells in good condition.
AA 2600 mAh cells got up to 137 F at mid cell and 135 F at the negative end where the C9000 monitors the cell temperature. These are also new cells, but they have high internal resistance and are not suited to high charge rates, or high discharge rates. At high charge and discharge rates, they heat up.
AA 2650 mAh cells got up to 128 F. These are new cells with moderate use.
AA 2600 mAh cells got up to 129 F. These are older cells with hard use.

Keep in mind that these are the peak temperatures that occurred during the last stage of the charge. The temperature actually peaks a few moments after the charge terminates. The cell temperatures during the bulk of the charge were in the 95 – 100 F range.

The C9000 monitors the temperature of each battery slot and terminates the charge if the cell temperature (measured at the negative end of the cell) exceeds around 135 F. There is no alarm indication when a cell terminates on high temperature. The C9000 simply terminates the charge and displays "Done" along with the charge time and mAh put into the cell.

The C9000 utilizes a very tight battery holder. A good connection is required for high rate charging. I have found that the easiest way to insert cells is to put the negative end in first and snap in the positive end. To remove the cell, press back to compress the spring at the negative end and tip the cell out positive end first.

The C9000 is about 6.5 inches tall, 4.5 inches wide and 1.5 inches thick. It has a lift rod that raises the back of the charger up for easier viewing and better air circulation. The power adaptor is roughly 2.875 inches tall, 1.875 inches wide, and 1.5 inches deep, not including the prongs that plug in.

A top off charge of 100 mA is applied at the end of the charge cycle for two hours. After that, a maintenance charge of 10 mA is applied for as long as the battery is in the slot.

Maha has a three year warranty on the C9000. To view more information on this excellent charger and to check out the owners manual, visit www.mahaenergy.com .

The C9000 was released in late December 2006. Early units had some difficulty terminating with a few cells, especially at lower charge rates. This review was done on a C9000 received in February 2007, and reflects improvements Maha has made to the charge algorithm.

Another big "thumbs up" to Maha. This is an excellent charger/analyzer. Simple enough for casual use, but offering advanced, sophisticated features for those times when we are trying to better understand the condition of our batteries, or when we are matching cells for multi cell use.

Tom
 
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EngrPaul

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Wow nice review! :goodjob:

I keep having issues with AAA batteries (I have been quiet about it lately... patient), so I'm going to check into the new model. I'm glad they responded to all our input and analysis.

I believe in the MAHA product. The more complicated these chargers get, the less likely they are to get it right the first time. I understand that :)
 

dekelsey61

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Tom,
Very nice review!! I have 2 of the newest versions of the C9000 and the changes are FANTASTIC!! Great charger with great features. Maha did a great job. This charger is everything you would expect from a charger and more. Again great job as always!!
Dan
 

TorchBoy

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So what exactly are the changes that have been made, why are the changes so fantastic, and are the old chargers lemons?
 

Burgess

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SilverFox -


As always, thank you once again for your time and effort.


You always keep up well-informed !


Best of luck (and health) to you and your loved ones in 2007.


goodjob.gif
 

HarveyRich

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Wow is right. This is a long and detailed review. I have recently purchased a LaCrosse Technology BC-900 charger that does virtually all of what you've described for the Maha C9000. The primary difference that I can see is that the Maha requires you to push a button to cycle the digital readout between cells, while the BC-900 has individual readouts for each battery (although they are smaller, they are easily readable). Thus, it would be faster and easier to visually see each battery readout. A comparison review I saw online indicated this and liked the BC-900 format. The BC-900 is also smaller and hence more portable. One main difference is the price. I was able to pick this up at Amazon for about $40, while the Maha C9000 seems to be going for about $65.

Otherwise, the two seem pretty comparable from what I've read. I love the BC-900 for all the reasons you state. They both seem to be excellent little chargers, especially for the digital readouts, single cell operation, and refresh battery modes. I would guess, that for full battery control, either charger would do the trick.
 

Perfectionist

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Will these manufacturers ever bring out a charger that does ALL battery chemistries ..... and RCR123 / RCR2 and maybe PP3 size cells too ??
 

SilverFox

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Hello HarveyRich,

There are similarities between the C9000 and the BC-900, however there are some differences as well.

Let's try a feature by feature comparison…

Size: The C9000 is roughly twice the size of the BC-900. Cells are easily accessed on the C9000 due to the generous spacing between cells. Cells are harder to access on the BC-900.

Power: The C9000 operates from either 100-240V 50-60 hZ AC or 12V DC.
The BC-900 operates only from 100-240V 50-60 hZ AC.

Display: The C9000 display is roughly 30% larger than the BC-900, and is backlit. The font that is used to display the information on the C9000 is larger and easier to read. The BC-900 displays one set of information for all 4 slots simultaneously. To see other information, you need to press the display button. The C9000 steps through all of the information for each slot twice, then moves on to the next slot. It takes roughly 15 seconds to go through two display cycles, so it takes roughly 1 minute to go through all four slots. Pressing the slot button on the C9000 will display the capacity value for a slot with additional presses giving the capacity value of the next slot in sequence. The display on the BC-900 is faster to use, but harder to read. Both provide similar information.

Capacity: The C9000 has a capacity limit of 20000 mAh on the Break-In mode and 4000 mAh on charging modes.
The BC-900 has a capacity limit of 3000 mAh.

Charge rates: The maximum charge rate for 4 cells with the C9000 is 2000 mA.
The maximum charge rate for the BC-900 with 4 cells is 1000 mA.
The C9000 allows you to select charge rates of 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, and 2000 mA.
The BC-900 allows you to select charging rates of 200, 500, 700, and 1000 mA for 4 cell charging, and additionally 1500 and 1800 mA for 2 cell charging in slots 1 and 4.

Trickle charge: The C9000 follows the main charge with a 100 mA top off charge for 2 hours, then supplies a 10 mA trickle charge. The top off charge and trickle charge rates are not displayed, and the trickle charge continues until the cell is removed.
The BC-900 is supposed to supply a trickle charge of about 5% of the charge rate selected. With a 1000 mA charge, it actually supplies around a 60 mA trickle charge. With a 700 mA charge rate, it trickle charges at around 40 mA. With a 500 mA charge, it trickle charges at around 28 mA. With a charge rate of 200 mA, it trickle charges at around 12 mA. The trickle charge rate is displayed, and the trickle charge continues until the cell is removed.

Temperature sensing: The C9000 uses a separate temperature sensor for each slot.
The BC-900 shares one temperature sensor for slots 1 and 2, and a second one for slots 3 and 4.

Discharge rates: The maximum discharge rate on the C9000 is 1000 mA.
The maximum discharge rate on the BC-900 is 500 mA.
The C9000 allows you to select discharge rates of 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000 mA.
The BC-900 allows you to select discharge rates of 100, 250, 350, and 500 mA.

Discharge mode: The C9000 discharges the cell down to 0.9 volts and stops. The discharge rate is selected by the user from the discharge rates available (default is 500 mA).
The BC-900 discharges the cell down to 0.9 volts and then charges the cell at twice the rate used for the discharge (default is 100 mA). EDIT: I have been asked to add that the BC-900 does not hold the discharge data. If you don't catch it before it starts charging, it is lost. ENDEDIT

Cycle, on the C9000 and Refresh, on the BC-900: These modes are similar, but there are some differences. Cycle on the C9000 prompts you for the charge rate (default is 1000 mA), the discharge rate (default is 500 mA), and the number of cycles you want to run (default is 1). It is capable of doing 12 cycles, and stores the mAh capacity for each cycle so you can go back and compare the different cycles after the process has completed. It starts with a charge, followed by a rest period, then a discharge once again followed by a rest, and finally a charge.
The BC-900 prompts you for the discharge current (default is 100 mA), then discharges the cell and immediately charges it at double the discharge current selected. There are no rest periods. This cycle continues until no further increase in capacity is estimated. The capacity during the last discharge is displayed at the end of this process.

Refresh and Analyze on the C9000 and Test on the BC-900: The C9000 prompts you for the charge rate (default is 1000 mA) and for the discharge rate (default is 500 mA). The cell is charged, followed by a rest period, discharged, followed by a rest period, and finally charged up again. The discharge capacity is displayed at the end of the process.
The BC-900 prompts you for the charge rate (default is 200 mA). The cell is charged, then discharged at half the charge rate, then charged again. There are no rest periods. The discharge capacity is displayed at the end of the process.

Battery condition check: When a cell is put in a C9000 slot and a charge rate is selected, a higher voltage will flash once during the display sequence. When this voltage is over around 2.0 volts, HIGH will be displayed indicating a damaged battery. When this voltage is around 1.7 volts, the cell will no longer be able to be charged on the 15 minute chargers because of higher internal cell resistance. Cells with very low internal resistance show up at around 1.45 volts.
The BC-900 also checks for battery condition. If the battery is within acceptable limits, it starts charging, if not, it displays NULL.

Warranty: The C9000 has a 3 year warranty.
The BC-900 has a 1 year warranty.

The C9000 has one additional mode, Break-In: When the Break-In mode is selected, the user is prompted for the cell capacity. The available capacities range from 500 – 20000 mAh in 100 mAh steps. The default is 2500 mAh. This mode follows the IEC standard for cell capacity testing. The cell is charged for 16 hours at a rate equal to one tenth of its capacity (0.1C), rested for an hour, discharged at a rate equal to one fifth of its capacity (0.2C), rested for an hour, then charged again for 16 hours at the 0.1C rate. The discharged capacity is displayed at the end of this process.

Cost: A quick check today revealed $62 - $65 for the C9000 and $36 - $70 for the BC-900.

Tom
 
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Doug S

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SilverFox said:
Trickle charge: The C9000 follows the main charge with a 100 mA top off charge for 2 hours, then supplies a 10 mA trickle charge. The top off charge and trickle charge rates are not displayed, and the trickle charge continues until the cell is removed.
The BC-900 is supposed to supply a trickle charge of about 5% of the charge rate selected. With a 1000 mA charge, it actually supplies around a 60 mA trickle charge. With a 700 mA charge rate, it trickle charges at around 40 mA. With a 500 mA charge, it trickle charges at around 28 mA. With a charge rate of 200 mA, it trickle charges at around 12 mA. The trickle charge rate is displayed, and the trickle charge continues until the cell is removed.
Tom
So do I understand correctly that even for a low capacity cell, suppose a 600mAhr rated AAA, it will charge another 200mAhr worth after termination by it's normal algorithim before going to the 10mA trickle?
 

TorchBoy

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Wow, Tom. I've come to expect a lot from you but I have to say that's an impressively in-depth comparison.
 

Codeman

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More great info from the master! Thanks, Tom!

I'm been using the MH-C9000 for about 2 months and I'm quite happy with it. Although my Triton was more than adequate for my AA's/AAA's, the new Maha make it so much easier since I don't have to switch charge cables. Although a fan would have been nice, I haven't had any cells reach 135°F, so I'm not really worried about it. My right 2 bays don't seem to like my Duracell 1000mAh AAA's, though. They don't snap into place, but I need to try Tom's suggestion of putting the cells in negative-end first. That may take care of the only real issue I have with the 9000. It, along with my Pila IBC and a Nano has my loose-cell charging needs covered quite nicely.

UPDATE - Thanks for the negative-end-first tip, Tom! :rock: That cleared up the problems I was having with my right 2 bays and the AAA's.
 
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lukestephens777

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This sounds like a fantastic charger for AAA's and AA's. Is there a charger like this one that will charge C and D size Nimh's? Or one that has a built in fan to cool cells? I like the full range of features this unit has.
 

SilverFox

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I have edited both my first post and the comparison with the BC-900. In both posts I stated that the C9000 discharges down to 1.0 volts. This only applies to the original unit. The improved C9000 discharges down to 0.9 volts.

Both of these posts should now be correct.

Tom
 

TorchBoy

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Strangely enough, I saw 0.88 volts momentarily on my MH-C9000 at the end of an AA discharge. A one-off quirk, I think - when it had cycled through to show the voltage again it was up to 1.2V. I probably do spend too much time looking at that display.

You haven't mentioned the repeating digit problem on the MH-C9000, Tom. :laughing:
 

SilverFox

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Hello Ian,

I still have not seen it, however I don't spend enough time looking at the display.

I am in the middle of something else now, but plan to check it out sometime in the future.

Tom
 

HarveyRich

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Silverfox: man, you are thorough--kudos. BTW, I still like my BC-900, especially at the price point. I'll await the next upgrade before splurging again. Thanks for the excellent comparison.
 

TorchBoy

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Yep Harvey, Tom's invaluable. The current firmware on the MH-C9000 is mostly OK and the problem I found is not a major if you're not worried about the thing working as it's supposed to. :whistle:

Some people don't even use that feature. I do, and it bugs me.
 
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