Capacity Mapping (Optimal Charge-Discharge Voltages)

Batteries, Chargers, and Battery Management Systems.
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DrkAngel
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Re: Capacity Mapping (Optimal Charge-Discharge Voltages)

Post by DrkAngel » Fri Oct 13, 2017 6:34 am

.
...
DOD is major factor in cycle life!

As I have long suspected, and advocated, tests and manufactures now indicate that DOD is a major factor in reducing\extending cycle life.

Manufacture clearly indicates discharging to 10%, rather than 0%, capacity doubles cycle life!
Image

Tests clearly indicate that avoiding discharging the last 10% of rated capacity provides greatly extended cycle life!
Image

My original reasoning was to avoid the voltage "cliff" indicated in all discharge graphs.
Going below this voltage produces the voltage sag and heat production indicating-exemplified by excessive discharge rates ... which we all know damage cells and cycle life.
There seems to be mounting evidence that DOD is nearly as critical as SOC in enhancing\degrading cycle life.
10%-90% seems to be promoted as optimal. (80% capacity with possibly 400% cycle life)
5%-95% might provide the greatest enhancement at the least capacity loss.
My testing seems to indicate that not dropping over the voltage cliff results in ≤ 5% capacity loss ... with a, now indicated, great extension in cycle life!

Please post any further proof of DOD as a major factor in cycle life ... :pancake:
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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DrkAngel
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Re: Samsung ICR18650-22p

Post by DrkAngel » Wed Nov 08, 2017 10:04 am

Just realized pairing Samsung HO cells with Sony or Samsung laptop cells is a bad idea!
3.7V "empty" laptop cells paired with 3.4V "empty" Samsung cells would be a bad, or at best wasteful, idea.

Samsung ICR18650-22p
Just completed:
2 x 5s2p 18.5V B&D power tool upgrades
2 x 3s2p 11.1V B&D power tool upgrade
s

2 x 7s12p 25.9V 26.4Ah eZip battery upgrades

Excellent speed and torque on power tools!
eBikes have noticeably improved speed and cold resistance.
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

New & Improved - Acronym Definitions

Index - Homemade Battery Packs - Updated - November 2015

EBike Toolbox - Bargains! $

Endless Sphere Wiki

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