Maha MH-C9000 SUPPORT / FAQ - continuation

[pobox1475]

The break-in cycle may revive the cell or at least give it some more capacity.

I assume the Break-In-Cycle is the best way to rejuvenate them. Would a standard Cycle(s) after a Break-In achieve similar results but save time? I am currently testing/doctoring about 16 1600 Rayovacs and have been doing so for 2 weeks now! Also should a Break-In be run on new Eneloops? Last question, I have been discharging my AA's at 300 and AAA @100 prior to starting the Break-In's (thus adding to the long times). Is this a good practice and should I use the Discharge in the future after I'm finished doctoring?

[Black Rose]

I assume the Break-In-Cycle is the best way to rejuvenate them. Would a standard Cycle(s) after a Break-In achieve similar results but save time?

The manual says to use Refresh & Analzye up to 3 times to try and rescue batteries. If the reported capacity is still low, then try a Break-In cycle.

Also should a Break-In be run on new Eneloops?

There has been some debate about that one. Most folks here appear to do a Break-In on Eneloops and other LSD/Pre-charged cells.

Last question, I have been discharging my AA's at 300 and AAA @100 prior to starting the Break-In's (thus adding to the long times). Is this a good practice and should I use the Discharge in the future after I'm finished doctoring?

It is better to discharge the cells before a Break-In cycle or even a normal charge cycle. I discharge my cells (AA or AAA) at 500 ma or 1000 ma.

[Nisei]

OK but what if, after trying a break-in, the capacity is still lower than the specs on the label? Should the actual discharge capacity then be considered as 1.0C? This also goes for Trustfire batteries: the specs are often bloated and sometimes the actual capacity is only 2/3 of the one on the label. Is it wise to check the actual discharge capacity and use that as 1.0C and ignore the specs on the label?

[Black Rose]

OK but what if, after trying a break-in, the capacity is still lower than the specs on the label? Should the actual discharge capacity then be considered as 1.0C?

This is my own opinion, but I think that the actual discharge capacity could be considered 1.0C, but that value will change over time, so it would need to be monitored.

One of the rules that SilverFox (our resident battery guru) uses is that for a new battery, if it's capacity comes in below 10% of the labelled capacity, he considers it to be a bad cell and returns it.

For a battery that is losing capacity with age/use, once it loses 20% of it's labelled capacity, it's recycled. As with anything, it depends on your own needs and what the cell is being used for.

Is it wise to check the actual discharge capacity and use that as 1.0C and ignore the specs on the label?

I believe that would be a safe assumption, but as the battery ages, that value will get lower over time, so what is 1.0C today could end up being 1.25C down the road and over-discharge the cell, causing more damage. Periodic capacity checks would be needed to make sure the cell isn't damaged.

[Nisei]

Great, thanks for the reply.

[Mr Happy]

OK but what if, after trying a break-in, the capacity is still lower than the specs on the label? Should the actual discharge capacity then be considered as 1.0C? This also goes for Trustfire batteries: the specs are often bloated and sometimes the actual capacity is only 2/3 of the one on the label. Is it wise to check the actual discharge capacity and use that as 1.0C and ignore the specs on the label?

Doesn't Trustfire imply a Li-ion cell? This discussion and the C9000 charger is very definitely for the NiMH chemistry. Break-in charges do not apply to Li-ion cells.

As to the actual capacity entered for the break-in charge, just use the nominal label capacity. The break-in process uses a low current and deliberately and harmlessly overcharges the cell in any case. When it discharges it stops when the cell voltage reaches 0.9 V. So there is no cause to worry about overcharging or over discharging if the cell doesn't perform to the label capacity.

Here is the reason. NiMH cells can lose apparent capacity and performance if stored for a long time without being used, or if given small charge discharge cycles without ever being fully discharged. The break-in process is designed to rejuvenate such cells and restore them to full capacity. If a cell does not recover after this process it may be considered for recycling since its performance has permanently degraded.

[pobox1475]

I have about 20 AA Rayovac 1600 Mah since 2005/6 that have not been used. With my new C9000 I have been running them through the Break In. I have started keeping track of capacities now that I am on the 2nd go round. The first four to finish came up as: 1036,1114,1133 and 1476. So once I run them through a third cycle and the three that are low do not improve to >=1280 it's off to recycler?

[Black Rose]

I have about 20 AA Rayovac 1600 Mah since 2005/6 that have not been used. With my new C9000 I have been running them through the Break In. I have started keeping track of capacities now that I am on the 2nd go round. The first four to finish came up as: 1036,1114,1133 and 1476. So once I run them through a third cycle and the three that are low do not improve to >=1280 it's off to recycler?

It's personal choice really...it depends on how critical their performance is for what you need them for.

I have some 2000 mAh Rayovac cells like that...I just use them in things like toothbrushes.

[lengendcpf]

I thought I learnt what I am supposed to know about charging rechargeables..I used to put in battery into a charger. The light lights up, after charging, the light goes off. I use the battery..

Now this charger confuses me.

If after the charger says done, meaning I can straight away take out the batteries? Or should I let them stay for 2 more hours of trickling charge for them to get fully charged? What will the display for that battery show?

Also, does the charge current makes any difference to the 2 hours of trickling charge? i.e. I charge a 2000mah battery using 500ma and another one using 1000ma current?

[Black Rose]

When the charger says done, you can take the batteries off if you want. Leaving the batteries on the charger for a couple of hours will just top them up.

I don't think the charge current makes any difference for the trickle charge. The trickle charge is 100 mA for 2 hours.

[lengendcpf]

Hi Black Rose, thanks for replying.


Regarding the refresh and analyse and also the break in..

Cause I read regarding rechargeables, most manufacturers say after few charges/discharges, the batteries will reach their rated capacities..

So is the refresh and analyse and the break in, necessary to perform?


One thing I like about this charger is the ability to set different levels of current. And can fast charge all 4 bays at the same time. 2A. Wow!

[Nisei]

I notice that Maha says the C9000 supports batteries up to 20,000 mAh. On the other hand they tell you not to charge at a rate below 0.3C. That contradicts because the highest charge current is 2000 mA making it only suitable for batteries up to 6000 mAh. Anyone else thought about this?

[Unforgiven]

I notice that Maha says the C9000 supports batteries up to 20,000 mAh. On the other hand they tell you not to charge below 0.3C. That contradicts because the highest charge current is 2000 mA making it only suitable for batteries up to 6000 mAh. Anyone else thought about this?

The MAHA MH C-9000 is designed for AAA and AA batteries. I have not found any of those size cells rated over 15% of the 20,000 mAh that you mentioned. Unless jumpers or some kind of adapters are used to try to charge batteries that it is not designed to charge, it is a non issue.

If one were to actually read through the MH-C9000 threads they would likely find that the updated firmware has changed a few things.

[Nisei]

A few years ago 1800 mAh was the maximum capacity you could buy. Now it's getting close to 3000! All I wanted to say is that Maha states this charger is future proof but as long as 2000 is the max charging current you can't charge anything higher than 6000 mAh if you stick to their 0.3C rule.

[Black Rose]

Regarding the refresh and analyse and also the break in..

Cause I read regarding rechargeables, most manufacturers say after few charges/discharges, the batteries will reach their rated capacities..

So is the refresh and analyse and the break in, necessary to perform?

They might not reach their rated capacity, but they will get closer to it in most cases.

Break-in mode just gives the cells a good start in their life and will also tell you if a new battery is bad.

Refresh and analyze is a quick way to find out if your batteries are losing any capacity.

One quick way to put a few charge/discharge cycles on the batteries is to use the Cycle mode. It charges and discharges X number of times, at the charge and discharge rates you choose.

[lengendcpf]

For 1.2V AA/AAA what is the voltage that determine that battery is bad?

Also the cell must be at what percentage of their manufacturer's rated capacity? i.e. an AAA cell rated at 850mAh but gives 805mAh(94.71%), is this cell ok?

[Black Rose]

For 1.2V AA/AAA what is the voltage that determine that battery is bad?

I have no idea. I think most use the capacity reported from the Break-in or Refresh and Analyze modes to determine if a battery is bad.

Also the cell must be at what percentage of their manufacturer's rated capacity? i.e. an AAA cell rated at 850mAh but gives 805mAh(94.71%), is this cell ok?

Is it a new cell or one you already had? Either way, that's a good one. It's only 5.3% off from it's labelled capacity.

[KuoH]

That's the most logical way I see of making a determination. I am now also labeling my batteries with the last test date and reported capacity so I can monitor the progression of each cell over time. I should add also, that I don't believe there is a magical number at which one should just throw away an old cell. It's really a matter of personal preference, but I have some cells that are at only 50% or so, which won't see any EDC out of the house duty, but would be perfectly good for any around the house, voltage compatible, low to moderate drain devices.

KuoH

I think most use the capacity reported from the Break-in or Refresh and Analyze modes to determine if a battery is bad.

[lengendcpf]

Hi, I am doing a refresh and analyze mode for one of my Recyko 2050mAh AA battery now.

At this moment, the slot is showing REST(after topping up, so now is the 2 hours rest period), I can only see: 24 min(time elapsed), 1.44 V and 886mAh (capacity?).


My question is why doesn't it show close to 2000mAH, since it has finished topping?

Btw the way, I am also doing a R&A for my Recyko 850mAh AAA battery at the same time, it shows: 70 min(time elapsed), 1.46 V and 55mAh (capacity?)

Is my charger's readings normal?

[lengendcpf]

Let me answer my own question.

Actually the capacity show after the topup during the rest mode is is the amount of energy put into the batteries. This number does not equal to the battery’s capacity as it is dependent on the amount of charge already in the battery as well as the battery’s internal resistance.

Ok, so my charger is working normally.


Some people have asked, for break in mode, if the battery capacity is xx50mAh, what should be the capacity to be entered?

Answer is Simply round up to the next capacity. For 2650 mAh battery, use 2700mAh capacity.

Actually all these can be found here

[pobox1475]

From what I gathered the only number that means any thing until Break In is finished is the time.

[lengendcpf]

This is the a very informative review.

Let you know more about your C-9000.

[lengendcpf]

Regarding the break in mode, can I just let the charger complete the 1st 16 hours of charge, then remove the battery? Does this consider "break in"? Or I must let it continue its discharge and another 16 hours of charge?

[Black Rose]

No, that is not a proper "break in". You need to let if complete it's full cycle.

The idea behined break in mode is to apply a steady charge for 16 hours, rest for an hour, discharge the cells to see how much energy the cell retained during from that 16 hour charge, and then charge it up again.

[lengendcpf]

No, that is not a proper "break in". You need to let if complete it's full cycle.

The idea behined break in mode is to apply a steady charge for 16 hours, rest for an hour, discharge the cells to see how much energy the cell retained during from that 16 hour charge, and then charge it up again.

But don't the discharge is just to find out the actual capacity of the cell?

Is there any documented proof that the proper break in must be done this way?

[Black Rose]

But don't the discharge is just to find out the actual capacity of the cell?

Yes, the discharge is used to find the actual capacity of the cell.

Is there any documented proof that the proper break in must be done this way?

Break In mode follows the IEC industry standard for capacity analysis, but is also referred to as a forming charge which gives the batteries a better start in life, which will in turn make them last longer.

[Mr Happy]

There's nothing to prevent you stopping after the first charge of course, but the discharge capacity is useful to know and two charges probably does a slightly better job of forming and conditioning than just the first charge.

[SilverFox]

Hello Legendcpf,

If you have no need or use for the capacity information, feel free to use the cell after the 16 hour 0.1C charge.

Tom

[lengendcpf]

Thanks Black Rose, Mr Happy and Silverfox for the reply, I think the most I drop the batteries in for 16 hours; just let them form the charge/capacity and use them..

[pobox1475]

I am trying to learn the "ins & outs" of battery care. My C9000 has been running break in cycles non stop for the past three weeks. I have 16 1600 mAh Rayovac's that have sat idle for about three years and only topped off on a Rayovac charger a few times. I have completed two complete run troughs keeping track of capacities the second go round. The lowest two being 898 & 1070 mAh and the highest 1509 & 1516. Now heres where the questions arise;

I was under the impression that break in cycles are good for the cells and the more run on them the better. During the third cycles I started with the cells that showed the lowest capacities and have found that the the first 4 have shown a reduction. 898 to 840, 1070/1020, 1092/1045 and 1114/1081. I am now concerned and want to know if this indicates that the cells are on their way out and should be given up on? Or if running back to back to back break in's is doing more harm than good? If these are basically poor cells (brand, original capacity or age wise) I can live with out them and get some new 2700's. I still have another dozen to work on and the top eight registered 1320 to 1516 mAh which I guess is not too bad. Should I continue with a third break in on the remaining cells? I intend to recycle any that are not worth using, which I assume would be the first 4 and any others that fall below 1200 mAh, which would be 75% of marked capacity. Let me know if there is a more semi-official guide line for drawing the line on performance/capacities.