# Any one konw the discharge rate of a given lithium battery

#### Minos2014

##### Newly Enlightened
I being asked how much of the discharge rate of my lithium battery , But i have no idea.

The lithium battery was a 3400mah 18650 lithium battery with protection board as below.

Can anyone helps answer it and how to calculate it correctly?
http://image4.pushauction.com/0/0/a...a795/89a19558-d9b2-2fec-fee8-beaf952394fe.jpg

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#### Nisei

##### Newly Enlightened
You can't calculate maximum discharge rate. It's a spec provided by the manufacturer.
Your picture is showing a Panasonic 18650B which has been tested here.

#### Minos2014

##### Newly Enlightened
• Recommend discharge current 1C 2.9A
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Does that mean the discharge rate is 1C?

#### ChrisGarrett

##### Flashlight Enthusiast
• Recommend discharge current 1C 2.9A
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Does that mean the discharge rate is 1C?

It means that you can discharge that cell at 2.9A continuously. I think that the XM-L and XM-L2 LED emitters are good up to 3.0A at X, Y or Z temperature.

Some of the new E-Cig doohickeys can drain a cell upwards of 7A, IIRC and some of the incandescent flashlights can go 20A, IIRC.

The Panasonic NCR18650B wouldn't be a good choice for those applications.

You would want to go with something like an IMR chemistry, or the new hybrid chemistries, which have discharge currents of up to 30A, ah la the Sony VCT5 cell and some of the Samsung cells.

Chris

#### Minos2014

##### Newly Enlightened
It means that you can discharge that cell at 2.9A continuously. I think that the XM-L and XM-L2 LED emitters are good up to 3.0A at X, Y or Z temperature.

Some of the new E-Cig doohickeys can drain a cell upwards of 7A, IIRC and some of the incandescent flashlights can go 20A, IIRC.

The Panasonic NCR18650B wouldn't be a good choice for those applications.

You would want to go with something like an IMR chemistry, or the new hybrid chemistries, which have discharge currents of up to 30A, ah la the Sony VCT5 cell and some of the Samsung cells.

Chris
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I can not understand your mean very well . I am sorry.
From this chart below,It shows the minimum discharge current is 2.928A.
http://image4.pushauction.com/0/0/a...a795/4e22b94c-a43d-a2d9-822c-bcb416278a99.jpg

#### ChrisGarrett

##### Flashlight Enthusiast
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I can not understand your mean very well . I am sorry.
From this chart below,It shows the minimum discharge current is 2.928A.
http://image4.pushauction.com/0/0/a...a795/4e22b94c-a43d-a2d9-822c-bcb416278a99.jpg

What you outlined is red is measured capacity in mAh, at those given discharge currents and not the MAXIMUM discharge current that that cell can safely handle.

You'd need to go to Panasonic's datasheet here for the NCR18650B:

http://industrial.panasonic.com/www-data/pdf2/ACI4000/ACI4000CE54.pdf

Looks like they test it at 2C max on that graph, which would be between 6-7A?

Chris

#### RoGuE_StreaK

##### Enlightened
HKJ's test shows the protection kicking in at about 6.5Amps. Seems to me to track be OK below that, as in it should be capable of discharging at up to say 6Amps. As for long-term impact of regular discharge at those rates, who knows; I guess that's why they have a "recommended" discharge rate.
Some batteries (radio control in particular) have "constant" and "burst" C ratings, essentially being the "recommended" rate and the "max (recommended)" rate.

Seems Panasonic can't calculate or missed something when updating their specs, as 1C should actually be 3.4Amps on a 3400mAh cell.

#### Minos2014

##### Newly Enlightened
discharge rate
[COLOR=#878787 !important]Web definitions[/COLOR]

• The rate, usually expressed in amperes or time, at which electrical current is taken from the battery.