Lithium ion Rechargeable batteries tests ( AA, battery packs etc)

[devagup]

Hello all, I am a QA manager located in the Netherlands and we conduct on site product inspections using a third party company in China. Some of our products use rechargeable batteries. I am looking to identify what kinds of tests our third party inspection company in china could perform on lithium ion rechargeable batteries(AA, battery packs etc). I contacted them and below is a list they provided. Are there any more tests perhaps you can think of which I can add to this list? If so, can you also please list what tools we should use to perform the tests? Thank you in advance.

Battery capacity - using a battery capacity tester.
Battery voltage - Multimeter
Charging and discharging time - loading tester (battery capacitor tester).

 

[rapparee]

Fluke BT521 Advanced Battery Analyser

Fluke's most advanced battery analyser Measure everything from battery current to temperature Ideal for use with all types of batteries

www.tester.co.uk

This tester may be of use to you.

It records 999 results, which maybe beneficial if you need to record results to comply with ISO 9001

 

[devagup]

Hi, yes I'm familiar with Fluke. Thanks.
I'd like to know what other kinds of tests we can perform on rechargeable batteries.
I've heard of ageing test and sensitivity test but I do not know what they mean and searching on Google didn't yield much results

 

[brianmoooore]

How well it survives a fall, and overall life, however it is abused, are the two most important tests for a battery pack for a cordless tool.

 

[devagup]

Battery pack meaning 2 AA batteries

 

[rapparee]

Battery pack meaning 2 AA batteries

No.

Meaning an 18v battery you would plug into a cordless drill.

Batteries are abused by their end user, are they robust enough?

 

[devagup]

I'm staying that I'm talking about AA rechargeable batteries

 

[Mike Johnson]

Each AA cell in a battery pack should have the same capacity or within a certain range to ensure compatibility when being charged, not just what is written on its case, the charge rate of each cell must be balanced, this can be by reducing the charge of one of the cells whilst still charging others, or by charging each cell individually, but this all depends on the compatibility of each cell to each other, each cell needs its own negative and positive lead to enable this to be carried out.

 

[devagup]

Thank you.
In general though, what kinds of tests could be done on rechargeable batteries apart from capacity check, voltage check and charge/discharge tests?

 

[Mike Johnson]

As far as I know there are no other tests that can be carried out without destroying the cell, the amount of amps that a cell can discharge at without destroying itself is important, but as long as the cell meets the requirements of its intended use that should be sufficient, the capacity of a cell gets lower the more often it is charged and discharged this can vary from cell to cell, hence the requirement to balance charge the pack, obviously keeping a close eye on the discharge threshold of the cells.

 

[Jim_e_Jib]

Are the company testing all of the batteries before each is accepted for use in a product or are they just checking samples from a batch to ensure general quality?

The number of charge/discharge cycles before capacity drops below a certain percentage might be useful as could the self discharge rate.

I imagine an AA battery has a specific size with an allowable tolerance. Does this need to be checked?

Likewise weight if the overall weight of your product is critical.

 

[devagup]

Jim_e_jib - thanks for your Inputs. They are only checking samples from a batch to ensure quality.
"The number of charge/discharge cycles before capacity drops below a certain percentage might be useful as could the self discharge rate." - yes definitely. Is this also referred to as an ageing test?

Also any idea what a sensitivity check is and also frequency response range check when testing rechargeable batteries?
Thanks.

 

[Jim_e_Jib]

Jim_e_jib - thanks for your Inputs. They are only checking samples from a batch to ensure quality.
"The number of charge/discharge cycles before capacity drops below a certain percentage might be useful as could the self discharge rate." - yes definitely. Is this also referred to as an ageing test?

Also any idea what a sensitivity check is and also frequency response range check when testing rechargeable batteries?
Thanks.

Hi, that probably is what is meant by an aging test, although whether there is also some element of physical aging that can be tested too. I guess that's tricky to assess if it's in real time.

Self discharge is how quickly a battery looses it's charge when it is sat on a shelf unused.

I've no idea on the sensitivity or frequency response check I'm afraid.

Is your product likely to be used in extremes of temperature? Could be worth getting charge and discharge rates at the expected temperatures to make sure they meet the spec you need.