Where does YOUR DSD terminate?

[bshanahan14rulz]

I've been monitoring mine with an ultrafire blue-label 18650 unprotected. It's at 4.22 right now, light is still red. I will post what the cell voltage was right at charge termination and a few hours after, but I was wondering what the rest of you have been getting?

Ultrafire 18650 blue label "2400mAh"
end of charge cycle voltage: 4.25V
resting voltage a few hours after charging:4.22V

2 hours after: 4.24V
3 hrs: 4.23V

 

[bshanahan14rulz]

same ultrafire: 4.24V after light turned green

 

[bshanahan14rulz]

Sanyo 18650: KB7M2A6

fresh off the charger: 4.23V

it quickly came to rest at 4.20V (within 45 minutes)

 

[bshanahan14rulz]

Did a pair of sanyo's using the new 5V 1.5A PS. Charged both to 4.23V. Will see if they drop later.
a pair of Sony's using 1.5A PS Charged both to 4.21V.

Strange, seems like it is overcharging by less than it used to on the old, weaker supply. charging voltage usually hits about 4.26V before quitting, but that could be due to meter error, charger sense resistor error, whatever. It's still good that it's terminating around 4.25V as it should. Would be nice to lose that last 100th of a V, but eh, whaddaya gonna do

Much faster now, took all of a weekend to charge a pair (on and off, as I had to leave the house a few times) using the 5.5V 450mA stock charger.

took 4 hours using the 5V 1.5A

 

[Sailhome]

Ultrafire 18650 grey 2400mAh
at green 4.21V
removed from charger for 1 hour 4.19V
It's been a good charger for 16340s and 14500 w/spacer.

 

[Oddjob]

IIRC you should try to stop charging at or before 4.2 volts for maximum longevity of the cells.

 

[Illum]

my DSD terminates sometime after the cell cuts out...because I've rarely seen it turn green, just from red to red/green indicating cell circuit cutoff

 

[jayflash]

Mine never gets the cells above 3.9 - 4.05 volts. If I want closer to 4.2v, I have to put CR123 cells into a Nano charger.

 

[The Dane]

@ bshanahan14rulz

What measuring instrument do you use?

In order to measure 0.01V reliably the resolution/error must be at least a factor 10 better.
So an error persentage of 0.1 or better in your DVM is nessesary for your measurements to be valid.

Fluke series 180 or better:shrug:

 

[bshanahan14rulz]

TheDane, ah, my accuracy then, will only be to a tenth of a V, then, and I shouldn't trust the multimeter's 100th place? It says extech, I'm just borrowing it from my boss: http://www.extech.com/instrument/products/000-099/22-816.html

Illum made some interesting points, and now I'm questioning the behavior of my DSD. Mine alternates green and red when plugged in w/ no battery. both red and green stay on when charging. when it stops charging, the red light turns off (the green might get brighter, or maybe it just looks like it does)

and Oddjob, that is correct. Manufacturers will say that the max is 4.25V, but how am I to know if 4.25 on my meter is actually 4.25. It is definitely something to look into and I'm thinking of trying to find how the dsd works and replacing any sort of sense resistor with one of the same value but higher tolerance rating to see if that helps.

 

[The Dane]

Sorry mate your DVM is only 1% so 4.20Volts could read anything from 4.16-4.24V.

 

[bshanahan14rulz]

what is the specification that I should look for that would tell me this information? say, if I want to try to find a multimeter that can tell me V to the 100ths place accurately, what key words should I look for?

 

[rizky_p]

isn't 4.25v is a borderline for lithium safety? at that high level you cells will be killed in no time.