Duracell pre-charged NIMH charge rates

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.

Yoda4561 said:

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.

Click to expand...

.5c = 1000mAh charge correct?

Zero_Enigma said:

.5c = 1000mAh charge correct?

Click to expand...

.5c = 1000mA (no h) charge current.

Black Rose said:

.5c = 1000mA (no h) charge current.

Click to expand...

Thanks for the help. So I assume .10c = 2000mA charge?

How does one calulate the math formulas for that .5c, .1c, etc? I only understand xxxxmA charges.

Thnaks in advance.

Zero_Enigma said:

Thanks for the help. So I assume .10c = 2000mA charge?

How does one calulate the math formulas for that .5c, .1c, etc? I only understand xxxxmA charges.

Thnaks in advance.

Click to expand...

For the purpose of this formula c = batteries labeled capacity.
.1c is 200 (one tenth of 2000).

hope this helps.

phenwick said:

For the purpose of this formula c = batteries labeled capacity.
.1c is 200 (one tenth of 2000).

hope this helps.

Click to expand...

Thanks fo rthe help

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!!??!!?

Zero_Enigma said:

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.

Click to expand...

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!!??!!?

Zero_Enigma said:

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.

Click to expand...

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!!??!!?

Zero_Enigma said:

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?

Click to expand...

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.

SilverFox said:

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.

Click to expand...

Re: WTF!? OVER-CHARGING BATTERIES!!??!!?

Hello Zero,

No problems that I can see so far...

Tom

Re: WTF!? OVER-CHARGING BATTERIES!!??!!?

Black Rose said:

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.

Click to expand...

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

Click to expand...

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!!??!!?

Zero_Enigma said:

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.

Click to expand...

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.