Rechargeable AA battery shoot out

[MattK]

Re: Ultimate AA battery shoot out

cause i prefer to use more heavy tests, that can help more who do a heavy use of batteries, like us of CPF that load batts at 4-5A, use several batts in series, use fast chargers etc. my test will se also how batts will degrade with different uses, like charge at 5A instead of 1.5A, overdischarge vs. partial discharge, discharge at 4A instead of 1A or 400mA

first comments after few charges:

ansmann 2850: arrived discharged, aren't real 2850 but around 2400-2500 at 1A of load, they can't handle 4A of load with decent voltage drop

ansmann max-e: arrived charged around 77% of capacity, are real 2000mAh and take quite well 4A of discharge

delkin ready to use: arrived at 25% of capacity, are only in the 1400-1500 range of capacity, 3 of 4 handle quite well 4A of discharge while one suffer much more

If you're doing multiple tests why not use an accepted, STANDARDIZED methodology for one of those tests?

It's fine and even desirable to do other tests but it's irresponsible and dishonest to claim cells do or do not make their rated capacities, as you have done in other threads, based upon a methodology of your own creation when the factory rated capacities are based upon an accepted STANDARD which is in use industry wide.

Who is charging at 5A? Why?

Again, your posts are misleading using the term 'real' since you aren't using the 'real' standard for battery capacity measurement.

Real: 'You keep using that word; I do not think it means what you think it means.'

 

[spencer]

Re: Ultimate AA battery shoot out

What is the standard?

And I can't unpack the zip file on my mac.

 

[davidefromitaly]

Re: Ultimate AA battery shoot out

If you're doing multiple tests why not use an accepted, STANDARDIZED methodology for one of those tests?

cause i prefer a method more near to our (or only my?) use

It's fine and even desirable to do other tests but it's irresponsible and dishonest to claim cells do or do not make their rated capacities, as you have done in other threads, based upon a methodology of your own creation when the factory rated capacities are based upon an accepted STANDARD which is in use industry wide.

i have tested other batts (not the ones included in this comparison) at 1/10C and there isn't a big difference compared to a 1A discharge, and sometime the capacity at 1/10C is less that at 1A, this is reported also in the tests made by silverfox

also if i discharge after 1 hour from the last charge i can obtain a higher capacity but this is caused by the state of overcharge of the anode that disappear in few hours, i prefer to discharge after 24 hours that is more near to a normal usage

i have to test only few batteries, maybe that i have some bad ones (for example i'm testing the energizer 2450 that give me only around 1100mAh, this don't mean that ALL the energizer 2450 are 1100mAh but mine for sure)

Who is charging at 5A? Why?

15min chargers arrive up to 8A of charge... btw i charge at 5A only one batt of every set of 4

Again, your posts are misleading using the term 'real' since you aren't using the 'real' standar
d for battery capacity measurement.

Real: 'You keep using that word; I do not think it means what you think it means.'

ok i can write "what my instruments read"

What is the standard?

And I can't unpack the zip file on my mac.

the standard for measure capacity is: charge at 1/10C for 16 hours, wait one hour, discharge at 1/10C

while when they declare the cycles use the charge at 1/2 to 1C with 10mV of minus voltage termination

as you can see, for declare the capacity they overcharge the battery reducing the life, for declare the cycles they charge at the correct capacity but they don't say that in this way the capacity is a little less

i upload both zipped and non-compressed version now

http://www.speedyshare.com/files/20666879/ultimate_battery_shoot_out.xls

 

[MattK]

Re: Ultimate AA battery shoot out

The IEC standard, grossly oversimplified is:

Before testing a battery may have up to of 5 charge/discharge cycles for break-in.
At ambient 20 °C ± 5 °C
- Charge at 0.1C for 16 hours
- rest for 2 hours
- discharge at 0.2C
- rest for 2 hours
- Charge at 0.1C for 16 hours.
- Discharge the battery and note the measured capacity
- repeat up to 5 times and pick the best result

15 min chargers are not good for regular NiMh batteries. There is a special 'fast charge' chemistry variant that is made. Companies selling chargers at those rates should specify special batteries only. These super high rate chargers almost universally make regular batteries too hot which lowers their charge acceptance considerably to the tune of 25-50% and significantly shortens cycle life.

Testing battery performance is very complicated because there is a huge amount of variables. This is why a STANDARDS exists so that we can measure them across a level playing field and have meaningfull capacity ratings.

To achieve any valid results you would consider:
- ambient temperature & airflow (real testing is done is a control oven)
-number of charge/discharge cycles on the batteries being tested.
-how it was charged (pulse linear etc)
-How the charge was terminated
-discharge current
-cutoff voltage during discharge
-voltage power supply stability
-instrumentation calibrated to within 1-2%
-some other stuff I must be forgetting

David, saying "what my instruments read," is no more accurate since your instruments are only part of the issue here.
Perhaps if you qualified that under your, "1.5C charge and 1A Discharge test regime you oberserved.." that would be a fairer way of expressing your results.

What I don't understand is that you want to make the 'Ultimate AA battery shoot out,' but you're not even close to using the standardized methodology, or some reasonable facsimile of, as at least one of your testing regimes.

 

[Rexlion]

Re: Ultimate AA battery shoot out

Maybe the thread should be renamed, "AA battery shoot out, my way". 'Cause it doesn't sound very ultimate IMO.

I can appreciate the tester's point of view to some degree. The testing standards may have been agreed upon by those in the industry, who necessarily have an interest in the resulting numbers (i.e., in keeping the numbers a little on the high side if possible, like 'do it 5 times and pick the highest result'). Nevertheless the standards yield a dependable, fairly repeatable way to compare the different cells at their optimum possible capabilities.

By contrast, I don't think this high charge/discharge testing method will yield results of high repeatability or dependability across the board, so the results will likely be of more limited usefulness and interest IMO. Not really ultimate.

 

[spencer]

Re: Ultimate AA battery shoot out

The IEC standard is not realistic of real use by people on this forum.

 

[MattK]

Re: Ultimate AA battery shoot out

Maybe the thread should be renamed, "AA battery shoot out, my way". 'Cause it doesn't sound very ultimate IMO.

I can appreciate the tester's point of view to some degree. The testing standards may have been agreed upon by those in the industry, who necessarily have an interest in the resulting numbers (i.e., in keeping the numbers a little on the high side if possible, like 'do it 5 times and pick the highest result'). Nevertheless the standards yield a dependable, fairly repeatable way to compare the different cells at their optimum possible capabilities.

By contrast, I don't think this high charge/discharge testing method will yield results of high repeatability or dependability across the board, so the results will likely be of more limited usefulness and interest IMO. Not really ultimate.

Exactly.

The IEC standard is not realistic of real use by people on this forum.

Based upon what information do you make this statement?

Now, that said, I don't think you're wrong but I'm not a fan of folks proclaiming things in an authoritative manner without FACTS to back up their OPINIONS.

The IEC standard is, as Rexlion points out, a consistent methodology which yields dependable results.

Speaking of 'real world," I don't think most people here charge at 1.5A or 5A, which is what David does. In my experience most people buy cheap chargers which are usually 500mA or less for AA's so if you want to go 'real world' I suggest using the cheap, low rate chargers most folks use for charging as a starting point. It won't be an accurate test - but it would be 'real world'.

 

[Anders]

Re: Ultimate AA battery shoot out

Hello David.

We all saw in Silverfox thread about Charger comparition that it was 47 % difference between the charger that did it best to the charger that undercharge the cells most.

https://www.candlepowerforums.com/threads/70935


When not using 0,1 C *16 h, it is very hard to compare any results from other tests at all.

This test is useful to compare your cells in this test but only if your charger always have the exact same charge termination on every cell, always.
I think it is hard to get the same results when using -dV.

What kind of charger do you use David?, it seems that I have missed that.

Thanks for the shoot out btw.

Anders

 

[davidefromitaly]

Re: Ultimate AA battery shoot out

ok, can a moderator modify the title with "rechargeable AA battery shoot-out" or "rechargeable AA battery stress test"?

i'm doing this test only cause all we know that IEC standard is unreal (like spencer say)

i want to know how last a battery when charged at 5A, 1.5A, when deep discharged or partially discharged, calculate the self discharge, see how the voltage drop at 4A of load, etc.

temperature is ambient temperature, so around 19-20C in winter and up to 28-30C in summer

i discharge with a CBAII and charge with a Robbe PowerPeak that is a RC charger like the Triton for example... they aren't calibrated but i see that datas are near to what i read here when other people do tests with CBA or C9000, 1-2% of difference, not more

so, i repeat, i don't want to do a IEC test cause nobody use batteries in IEC way, if you use the IEC standard read the battery datasheet, if you use the battery like me read my test

 

[PeAK]

Re: Ultimate AA battery shoot out

ok, can a moderator modify the title with "rechargeable AA battery shoot-out" or "rechargeable AA battery stress test"?

You can rename yourself...maybe call it "My Way"

...
so, i repeat, i don't want to do a IEC test cause nobody use batteries in IEC way, if you use the IEC standard read the battery datasheet, if you use the battery like me read my test

I find that SilverFox's "Shootout" to be the most useful and if you want to use the word ultimate, I would say his is closer to the ultimate in terms of thoroughness. What do you find lacking in his tests that would want you to do your own thing ?

 

[MattK]

Re: Ultimate AA battery shoot out

i'm doing this test only cause all we know that IEC standard is unreal (like spencer say)

i want to know how last a battery when charged at 5A, 1.5A, when deep discharged or partially discharged, calculate the self discharge, see how the voltage drop at 4A of load, etc.

i discharge with a CBAII and charge with a Robbe PowerPeak that is a RC charger like the Triton for example... they aren't calibrated but i see that datas are near to what i read here when other people do tests with CBA or C9000, 1-2% of difference, not more

so, i repeat, i don't want to do a IEC test cause nobody use batteries in IEC way, if you use the IEC standard read the battery datasheet, if you use the battery like me read my test

I know what you're saying however:
1 - charging at 5A and 1.5A is not real world for most users.

2 - charging with a Robbe PowerPeak RC charger and discharging with a CBAII is not 'real world.

3 - continuous discharge is not real world - most people cycle and rest their battery powered products numerous times.

4 - A CBAII is far more accurate than a C9000 and NEITHER is within 1-2%.

No one uses the battery like you or your methodlogy. Your test is no more real world than the IEC standard. That's what got me started on the 2 threads - when you said 'real capacity' with regards to the Ansmann. Your test is no more or less 'real' than IEC.

 

[davidefromitaly]

Re: Ultimate AA battery shoot out

You can rename yourself...maybe call it "My Way"

i can't... i'm waiting for a moderator

I find that SilverFox's "Shootout" to be the most useful and if you want to use the word ultimate, I would say his is closer to the ultimate in terms of thoroughness. What do you find lacking in his tests that would want you to do your own thing ?

i really like the tests by silverfox but:

1. i'm testing other battery brands
2. i'll evaluate the health of them during the whole life
3. i'm testing the self discharge and how it change during life
4. i'm testing variuos charging and discharging method

 

[PeAK]

Re: Ultimate AA battery shoot out

i can't... i'm waiting for a moderator

As I said...you do not need a moderator to rename your thread. Go to "Advanced Menu".

i really like the tests by silverfox but:

1. i'm testing other battery brands
2. i'll evaluate the health of them during the whole life
3. i'm testing the self discharge and how it change during life
4. i'm testing variuos charging and discharging method

He has already done item #2 and #4 but you can easily find those threads yourself. There are various others doing #3, it would be a waste of buying batteries and time to do all the brands you specified, yourself, better to distribute the task and use search in these forums as different members already have provided that information for different brands they use.

That leaves item #1 and I think Matt's point cannot be overemphsized. Use standard testing practices so that we are not comparing apples and oranges.

 

[kramer5150]

Re: Ultimate AA battery shoot out

I use energizer 2450 and just got some rayovac 4.0 cells. Even though I don't charge / discharge mine anywhere near your test conditions... still I am interested to see how well they hold out.

You dont need a mod to change a thread title. Just double click to the right of your thread title, in the sub-forum listing page.

 

[davidefromitaly]

Re: Ultimate AA battery shoot out

I use energizer 2450 and just got some rayovac 4.0 cells. Even though I don't charge / discharge mine anywhere near your test conditions... still I am interested to see how well they hold out.

at what rates you charge and discharge?

i'm at the first cycles of the energizer 2450 and i can say that all 4 on 4 of them are unable to charge with -dV at 1.5A and 5A, i'm charging them with dT

and most important they have only around 1100mAh of capacity at 1A of discharge, i think i have 4 damaged batteries

the "good" thing is that they hold the voltage quite well

i have also 4 energizer 2300 "new formula" and they are far better

 

[davidefromitaly]

Re: Ultimate AA battery shoot out

As I said...you do not need a moderator to rename your thread. Go to "Advanced Menu".

in the advanced menu i can modify the post title but not the thread title, any moderator can confirm this

 

[teo_92]

ciao davide!! sono teo_92 di cpfitalia....per favore contattami via mail che non so più cosa fare per entrare nel forum italiano e mi serve un e-mail di un utente dato che sono interessato ad una sua inserzione...la mia mail è: [email protected]
fammi sapere al più presto per favore....grazie mille!!

 

[DM51]

Welcome to CPF, teo 92.

Unfortunately we are not set up to moderate posts in languages other than English. Posts in other languages are liable to be deleted at the discretion of CPF staff.

 

[Archie Cruz]

Welcome to CPF, teo 92.

Unfortunately we are not set up to moderate posts in languages other than English. Posts in other languages are liable to be deleted at the discretion of CPF staff.

He's saying that he can't get into CP Italy. Not much there to moderate

 

[DM51]

He's saying that he can't get into CP Italy. Not much there to moderate

I understood enough to see it didn't need to be deleted. If I had been unsure, it would not have remained there long enough for you to practice your translation skills.