A Dumb Question about Panasonic NCR18650B Protected 3400mAh Cells

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indenial
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A Dumb Question about Panasonic NCR18650B Protected 3400mAh Cells

I decided to test my SRK with a new set of four protected Panasonic NCR18650B cells to see how long they could last on high mode.

Suffice it to say after several hours the light went dim. But when I tested the batteries with my multimeter they were dead. I mean 0.00 volts!

Isn’t the protection circuit supposed to keep them from fully discharging? I guess my batteries are worthless at this point.

If I’m missing the obvious please enlighten me. I’m here to learn! Thanks.

My name is indy, and I've been a flashaholic since 2004.

NightCrawl
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The protection is tripped and therefore showing 0.00V. They will be good again when you charge them.. if you have a good charger. Wink

But for the next time: its never a good idea to run batteries until the protection shuts them off.

FMcamaroZ28
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What charger do you have?

Most likely you can toss them in the charger for 1 sec and that will reset the protection.

But yeah, not a great idea to do what your doing.

indenial
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Nitecore Intellicharger I4. I placed them in the charger and they reset and are now at 2.76v.

Is it a good idea to recharge them or should I just toss them?

Thanks.

My name is indy, and I've been a flashaholic since 2004.

Halo...
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Panasonics are pretty reliable, they should be ok.
As long as they are real panasonics. Where did you buy them?

FMcamaroZ28
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If they are legit panasonics, charge them up. they will be fine.

relic38
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Most protected cells use the same protection chip, which has a trip point of 2.4-2.5V. This is well below the manufacturer rated voltage of 2.75V. Repeated discharges to 2.5V will probably degrade your cells. The result will be lower capacity and increased internal resistance.
Charge em back up, they should be fine.
I will note that protected Panasonic NCR18650B 3400mAh cells do not make a lot of sense. The fully charged voltage is 4.35V. The overcharge voltage of the protection chip is 4.25-4.30V. You would never be able to get a full charge in the batteries. On the plus side, cycle life span would be higher when not fully charging.
Edit: Crossed out apparently erroneous information. I looked for a Panasonic datasheet on panasonic.com and they list the cell with no datasheet.

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RedForest UK
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Actually, the full charge for NCR18650B is 4.2v, I don’t know why so many people keep claiming it is 4.35v as that was a misprint by CNQG.

2.76v should be ok on the NCRs, even for regular discharges, as they are rated down to 2.5v. Many other brand cells don’t like to go below 2.75 or even 3 though.

indenial
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I got them at fasttech.com….Thanks for the help!

My name is indy, and I've been a flashaholic since 2004.

BIGWOOD
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I thought the NCR18650B 3400mAh batteries are fully charged up to 4.2V and not the 4.35V (as it was first rumored)

Indenial was using it under load on high. So when the protection kicked in the resting voltage would have been alot higher.

Someone pls correct me if I’m wrong.

NightCrawl
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Yes, NCR18650B are 4.2V down to 2.5V. Protection usually trips around 2.4V, if they had only 2.76V after 1 hour in the charger, they were really down to around 2.5V. They wont explode or really suffer from that, but doing that more often will let the cell age earlier.. the PCB is there to protect the cell, not to turn the light off.

NightCrawl
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kreisler wrote:

4.35V is Corea cell

Since when is Japan part of Corea?

NightCrawl
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kreisler wrote:

you miss quoted me hehe.

i wanted to write 4.35V is Samsung.

Silly

Also wrong, 4.35V is Samsung, LG and Sanyo. Silly

kreisler
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NightCrawl wrote:

kreisler wrote:

you miss quoted me hehe.

i wanted to write 4.35V is Samsung.

Silly

Also wrong, 4.35V is Samsung, LG and Sanyo. Silly

kreisl diffusing wrong info? omg

sollie. it's already deleted.

da gone!!

*FMI* i got 4 i/o sh