Duracell pre-charged NIMH charge rates

Zero_Enigma

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Toronto, Canada
Ok, I got opened up a package of Duracell Pre-charged batteries. I did a discharge the moment I got them at 100mAh on my Maha C-9000 charger.

These are my results:

Purchase location: Canadian Tire (Leslie & Sheppard, Toronto)
Discharge rate: 100mAh
Cell 1: 1459mA, 983mins, 1.18v
Cell 2: 1456mA, 981mins, 1.18v
Cell 3: 1453mA, 969mins, 1.18v
Cell 4: 1473mA, 992mins, 1.17v

I would like to know what charge rate I should normally subject these cells to after the 'break-in' mode? Or do I need to even do a 'break-in' mode for these type of cells?

Thanks in advance.
 
Go ahead and do a break-in. They don't really need it, but it can't hurt either. I recommend .5c charge rate, or 1000mah. The C9000's default charge is perfect for most modern AA nimh's, including lsd.
 
WTF!? OVER-CHARGING BATTERIES!!??!!?

Ok. Sorry for the delay.

My Maha C-9000 model # is 0G01A

As of now (05:53 EST) the following stats on the two cells I'm using 'break-in' mode are:

Brand: Duracell Precharged
Capacity: 2000mAh

Cell 1: 2188mA, 199mA charge rate, 726min, 1.49v
Cell 2: 2188mA, 199mA charge rate, 726min, 1.49v


Is the charger overcharging the batteries? I think it is because of the 1.49v but I could be wrong. Should I be alarmed here?

Silverfox you around?


I didn't charge all 4 banks because given the break-in mode takes like 36-48hrs I want two bays open should I need to charge something else.
 
Re: WTF!? OVER-CHARGING BATTERIES!!??!!?

Ok. Sorry for the delay.

My Maha C-9000 model # is 0G01A

As of now (05:53 EST) the following stats on the two cells I'm using 'break-in' mode are:

Brand: Duracell Precharged
Capacity: 2000mAh

Cell 1: 2188mA, 199mA charge rate, 726min, 1.49v
Cell 2: 2188mA, 199mA charge rate, 726min, 1.49v


Is the charger overcharging the batteries? I think it is because of the 1.49v but I could be wrong. Should I be alarmed here?

Silverfox you around?


I didn't charge all 4 banks because given the break-in mode takes like 36-48hrs I want two bays open should I need to charge something else.
There are several threads on charging LSD batteries on the C-9000 using break-in mode. A search should turn them up for you. Many are about Eneloop batteries, so you might want to use that as a search term.
 
Re: WTF!? OVER-CHARGING BATTERIES!!??!!?

Ok. Sorry for the delay.

My Maha C-9000 model # is 0G01A

As of now (05:53 EST) the following stats on the two cells I'm using 'break-in' mode are:

Brand: Duracell Precharged
Capacity: 2000mAh

Cell 1: 2188mA, 199mA charge rate, 726min, 1.49v
Cell 2: 2188mA, 199mA charge rate, 726min, 1.49v


Is the charger overcharging the batteries? I think it is because of the 1.49v but I could be wrong. Should I be alarmed here?

Silverfox you around?


I didn't charge all 4 banks because given the break-in mode takes like 36-48hrs I want two bays open should I need to charge something else.

It's fine, that's a 100% charge on a nimh cell. 1.2v is actualy mostly drained, it's alot like lithium ion "3.6v" where the cell is actually 4.2 volts when fully charged.
 
Re: WTF!? OVER-CHARGING BATTERIES!!??!!?

Is the charger overcharging the batteries? I think it is because of the 1.49v but I could be wrong. Should I be alarmed here?
That's normal when using the break-in mode.

I believe it has something to do with charge efficiency of the batteries.

SilverFox answered a similar question a few days ago about it.

I'll see if I can find it.
EDIT: Here it is.

The Break-In charge is an attempt to match the industry standard charge. That is 16 hours at 0.1C.

At low charge rates, the charge effiency is not all that good and it takes about 60% more charge to end up with a full charge.
 
Last edited:
Re: WTF!? OVER-CHARGING BATTERIES!!??!!?

That's normal when using the break-in mode.

I believe it has something to do with charge efficiency of the batteries.

SilverFox answered a similar question a few days ago about it.

I'll see if I can find it.
EDIT: Here it is.

Thanks for the linking. Sometimes is easier to post a message as I don't always have the time to do the search when my web time is sparse or hit-miss (wifi on the hit-miss). I do search when I have time but when you're in a rush sometimes I just post.


SilverFoxRe: WTF!? OVER-CHARGING BATTERIES!!??!!?
Hello Zero,

No problems that I can see so far...

Tom

Thanks mate.


Well those numbers I posted are before I passed out to sleep and it was still charging. Last time I did a 'break-in' mode on new Duracell 2650mAh cells the charging IIRC kept on charging into the 3100+mAh and climbing last I checked. I was shocked then. Most of the independant reviews I've read ( like the big batteries tested one on the website I forgot but the guy does camera reviews/accessories) which it seems if the cell holds well it can hold ~10% it's marketing claim on the really good cells. When I noticed it charging above 3100mA that time it puzzled me but I didn't post then as I forgot.

Well thanks again for all those helped.
 
Re: WTF!? OVER-CHARGING BATTERIES!!??!!?

Well those numbers I posted are before I passed out to sleep and it was still charging. Last time I did a 'break-in' mode on new Duracell 2650mAh cells the charging IIRC kept on charging into the 3100+mAh and climbing last I checked.
It's OK. The break-in mode does a deliberate overcharge of batteries using a low enough charging current that it doesn't harm them. Even so, the break-in or conditioning charge is not something that should be used routinely. Just reserve it for conditioning new cells and periodic refreshing of older cells that are under performing or that have been in storage for a while.
 
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