1000 mAh AAA + Energizer 15 Minute Charger

[pd54]

I've had the 15 minute charger for about a week now and it has been doing great with my 850 mAh Energizer AAAs. I'm want a couple more AAAs and I was thinking of getting a couple 1000 (or higher, if they make them) mAh batteries. Where is the best place to buy good 1000+ mAH AAA batteries? I'm also wondering if they will work in the charger (the instructions say to only use Energizer batteries). It says:

[ QUOTE ]
To reduce the risk of injury, charge only Energizer rechargeable Ni MH battery with the charger. Other types of batteries might burst, causing personal injury or damage to your charger.

[/ QUOTE ]

Will the higher capacity batteries do fine, just taking a little longer to charge?

 

[SilverFox]

Hello PD,

Welcome to CPF.

That charger should have no problems with the 1000 mAh AAA's. Not sure where you get them.

I have charged over 25 brands of cells with the Energizer 15 minute charger. No problems so far...

Tom

 

[pd54]

Thanks for the info!

I just looked around and 1000mAh seems to be the highest. I found a couple places that sell some:

Thomas Distributing

BozCorp

I'd probably go with Thomas Distributing...I only want 2 at the moment, and they look more trustworthy (plus I get a free battery holder! /ubbthreads/images/graemlins/happy14.gif)

Anybody have any experiences with them?

 

[Flash_Gordon]

Hi pd54-

Here is a link to the only high power NiMH AAA that I am aware of. Accupower AAA

I have not used these, nor do I have experience with the Accupower brand. Others here probably have. However, I have bought batteries from Thomas Dist. for years and they are a top notch company to deal with. I am using Maha Powerex 800ma AAA and I know that most all NiMH producers have limited their AAA cells to 800-850ma. Is there a sound reason for this?

As Tom said, you can use your charger for any brand as long as you stay with the chemistry for which it was designed.
Of course the Bunny only wants you to buy Bunny batteries.

Welcome to CPF
Mark

 

[paulr]

I'm skeptical of that 1000 mAH claim til I see independent test results. mAH ratings are overstated an awful lot of the time.

 

[Empath]

[ QUOTE ]
Flash_Gordon said:
I know that most all NiMH producers have limited their AAA cells to 800-850ma. Is there a sound reason for this?


[/ QUOTE ]

In the earlier days of NiMH, I learned that NiMH cells were capable, by far, of greater total capacity than NiCD of the same size. The reasons given for not utilizing the greater capacities is that the internal resistance would rise considerably as the capacity, for size, went up. Avoidance of internal resistance was important, due to the advisability of making up the power difference of replacing 1.5 volt cells with 1.2 volt.

With the steady increase in NiMH cells, I've often wondered if the problem had been addressed, or ignored. I've never taken time to test; just wondered.

 

[paulr]

Yeah there are two ways of constructing NiMH cells, basically the low IR and lower capacity way, and the higher IR, higher capacity way. The Sanyo 2500's are the high capacity type, the CBP 1650 is the low IR, lower capacity type.

 

[Lurveleven]

I have the AccuPower 1000mAh AAA bought from Thomas Distributing and can highly recommend them. Here are some test results of them:

Notice that I have tested them as high as 3A, something even some AA batteries have problem with.

Sigbjoern

 

[pd54]

When a battery has a high capacity mAh (say, a 1000 vs. 850), will the only difference will be in runtime? Will there be a brightness difference too?

 

[SilverFox]

Hello Sigbjoern,

Nice graph... /ubbthreads/images/graemlins/smile.gif

It looks like they are struggling a bit at 3 amps, but still keep up. The temperatures must be going up at those loads.

Tom

 

[paulr]

Thanks for the graphs, Sigbjoern. Can you do one at C/10 = 100 mA? I think that's how NiMH cells are normally rated.

 

[SilverFox]

Hello Pd,

With direct drive, you look at the voltage retention of the cell. A cell that has a mid point voltage of 1.1 volts will produce brighter results than one that has a mid point voltage of 1.0 volts.

When you get to the various circuits things change a bit. You need enough voltage to make the circuit work and anything above that is kind of wasted. Once you have the voltage you need, then the capacity determines run time.

Tom

 

[Lurveleven]

[ QUOTE ]
paulr said:
Thanks for the graphs, Sigbjoern. Can you do one at C/10 = 100 mA? I think that's how NiMH cells are normally rated.

[/ QUOTE ]

I have updated my initial post with results at 100 mA. Hit the refresh button to see the updated graph.

Sigbjoern

 

[paulr]

Looks like about 850 mAH before nosedive, the 1000 mAH figure is exaggerated as expected. Thanks.

 

[snakebite]

did you break these in before the test?
[ QUOTE ]
Lurveleven said:
I have the AccuPower 1000mAh AAA bought from Thomas Distributing and can highly recommend them. Here are some test results of them:

Notice that I have tested them as high as 3A, something even some AA batteries have problem with.

Sigbjoern

[/ QUOTE ]

 

[Lurveleven]

The break in was done by SilverFox so they should be properly broken in. Note that for the 0.1A test, the cells were rested for a couple of hours before testing, I don't remember for the other tests because they were done two months ago, but they were rested at least half an hour. Btw, I just got the datasheet for these cells. This contains the results AccuPower has performed in their R&D lab, I will soon get some info on how those tests were performed, to find out what causes the discrepancies in my measurements. Even though I got less capacity (890 mAh) at 0.1A, I got a higher voltage under load than what they have in the datasheet so the Wh may be the same. I may redo the test later using a different charger and with the cells hot off the charger to see if I'm able to match AccuPowers own measurements.

Sigbjoern

 

[pd54]

Thanks for the graphs Lurveleven! /ubbthreads/images/graemlins/smile.gif

So if the 1000mAh batteries are actually running around 850mAh, would it be better to just buy some Energizer 850 mAh locally? I think I can get a 4pack for around $9 or so.

 

[pd54]

Anyone?

 

[SilverFox]

Hello Pd54,

My answer would be... Can you live with 700 mAh cells? I have not tested the Energizer AAA 850 mAh cells, but every other NiMh cell comes in under the rated capacity and I would be surprised if Energizer broke the trend.

Tom

 

[pd54]

Hmm...well, here's the way I'm looking at it:

The Accupowers are supposedly 1000mAh - they will cost, at best, about $10 shipped (for 2).

The Energizers are supposedly 850mAh - they will cost locally around $10 with tax (for 4).


Basically, even though they are the same price, will the Accupowers (2) be a better buy than the Energizers (4)? I have the 15 minute charger, so having extras lying around aren't a big deal to me (although extras are always welcome /ubbthreads/images/graemlins/grin.gif) If the difference in power is very minimal, than I would go with the Energizers.