battery weight database to detect deterioration

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causeless
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Location: Tokyo, Japan
battery weight database to detect deterioration

Does anyone know battery reviews or database include weight of batteries?
There are many great reviews and databases like BLF's but I couldn't find such a DB.

Or, could it be possible to add "Weight" column to BLF database?
To identify batteries and detect deterioration in the quality, it would be really useful information especially for who don't have analyzers like me.

Good points I could bring are,
1. a number of members would have digital kitchen scale (at least than who have battery analyzer).
2. deterioration in qulity of the brand may decrease weight from value reviewed before.
3. In my small list below, the weight seems to be roughly related to their capacity.

crown 1500cycle eneloop AA 25.89g
1000cycle eneloop AA 26.24g
>5years old green/orange GP AA 1600mAh 24.53g
>3years old SONY cycle energy AA 2150mAh(min) 28.39g
generic volcanoVZ AA 1300mAh (from Japanese dollar-store) 22.15g
blue unprotected ultrafire TR18650 2400mAh (from tmart) 45.57g
blue unprotected generic ICR18650 2400mAh (from ebay) 45.25g

Don
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The problem is that affordable devices can't be trusted at the 10 milligram level - the second digit will be dubious in the extreme. Come to that, most of them can't be trusted at the 100mg level.

I do have a proper lab balance somewhere in the loft, but the weights are at least 60 years old and are in ancient Imperial units. I'd need to set it up on a properly stable bench and encase it. I hate using ancient lab balances but at least it would have the required accuracy. Once I'd got it temperature controlled properly.

 

If there is a measurable weight loss in an NiMH cell it has vented some of the very carefully calculated amount of water in it - probably as hydrogen and oxygen and as a result the cell has been badly damaged.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

causeless
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sorry, my poor janglish confused you...

it's hard to detect damaged cell by precise weight. 1Ah loss means only 35mg hydrogen vapor.
i think 1g precision is enough to detect overrated/fake cells and bad batch of each brand. The weight will vary significantly when manufactures start to reduce active material in exchange for capacity and their credit.

Don
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There's absolutely nothing wrong with your English - I didn't notice you were from Japan until now. Certainly the fakes will almost certainly be lighter - the rechargeables sold in my local pound shop weigh next to nothing.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

sixfink
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My precision scale used for weight-matching engine internals is good for 0.2g at the most. Below that readings are still displayed, but become increasingly erratic.

Good thinking on the temperature, Don. My old ZEISS micrometer calipers (and an English pre-war Moore&Wright) have the proper temperature for measurements etched in on the frames.

cessnapilot
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Here is a scale that does .1g increments for $6.5 and good reviews. I just ordered it right now, since I have some other uses for it as well.  I can report on it when I get it if anyone is interested    ----  http://www.dealextreme.com/p/portable-digital-pocket-scale-500g-0-1g-2-a...

here is on that does hundredths of a gram but reviews say it is only really accuarate up to 40g   LINK