when to replace rechargeables due to endurance...

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turkeydance
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when to replace rechargeables due to endurance...

essentially; for you, what determines
the end-point of a rechargeable battery?

here are my details:
an 18650 is slowly dying.
it will hold a charge for continuous use
for around 30-40 minutes. after that,
the output dims the light significantly.

what is your ONE sign to decide to discard and buy a new one?
age? corrosion? yes, there can be multiple indicators….
i would like to know what is your one-and-done?

ChrisGarrett
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80% of original capacity is what the hacks in Vegas tell us.

Chris

BlueSwordM
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I pretty much never replace rechargeable cells, especially since I take care of them so well.

Anyway, I’d go for 70% of original capacity and significantly increased for IR to derate them and use them in other applications.

My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547

jon_slider
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I have some old AAA eneloops and when new they gave
80 lumens, but now, 7 years later, they only achieve
35 lumens. Since I dont use high mode, Im happy to keep using them at the
15 lumen output level that the medium mode provides.

I did recently order new Eneloops.. I feel Rich in Lumens again

TIFisher
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I’ve only been into this “hobby” for 18 months or so. I bet I only have one or two cells that have been cycled more than 4 or 5 times, and have probably a dozen cells that have never been used. I doubt I’ll ever see a situation of significant capacity loss due to high cycle counts. The only thing I would ever be concerned about is high internal resistance, but I’ve read conflicting schools of thought on what constitutes values high enough to warrant discontinuing use of a particular cell. The caveat here as well, is having an accurate method to measure/calculate IR. My Opus allegedly performs the function, but I don’t necessarily believe it to be more than a rudimentary guess as the values are so inconsistent.

wle
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i don;t have a test

i throw them out if

a. they heat up when charging
b. they seem to never finish charging
c. the run time seems too short
d. i get better newer cells, and or start to get too many i am never using

"You never have the wind with you - it's either against you, or you're having a good day."
    Daniel Behrman, "The Man Who Loved Bicycles".
It never gets easy, you just go faster.   
-Greg Lemond.
       ,ø¤º°`°º¤ø¸,ø¤º°`°º¤ø¸,ø¤º°`°º¤ø¸

Helios azimuth
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wle wrote:
i don;t have a test

i throw them out if

a. they heat up when charging
b. they seem to never finish charging


Me too. The only batteries I have sent to the recycle bin have had charging issues or do not hold voltage.
Serlite
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I found that one of the Sofirn 21700s I had was completely drained in a light I thought I’d locked out.

The battery charged up just fine and it even did fine in the capacity test…but after leaving it off the charger a while and checking on it, I noticed it was warmer than an identical cell sitting nearby. I measured the voltage and also noticed a significant drop, suggesting an internal short. Over the next few days it regressed back into a fully discharged state.

I don’t often toss Li-ion cells, but this was a clear sign that this cell was ready to retire. It’s currently waiting for recycling, as soon as I can visit a drop-off for them.