Efest at it again!!!!

[b1mble]

Nov 8, 2014 12:17:52 GMT Bob said:

The main problem facing us now is that the Sony VTCs are getting very hard to find, what we need is a comprehensive list of what the capabilities are of the batteries available, along the lines of: battery name, size, mAh, Max Amp (both Continuous and Pulse).

As I was getting low on Sonys, i've just bought 4 x Samsung 18650-25R which are supposed to be good, I know the 20R were tested and actually okay up to 22A, but I haven't found any testing for the 25R.


EDIT: I have now on that German site linked to in the OP and according to them the Max is 20A for both those Sammys

Try Cell data. These are all the cells that three of us have tested.

[VapingBad]

Nov 8, 2014 20:30:25 GMT b1mble said:

Nov 8, 2014 12:17:52 GMT Bob said:

The main problem facing us now is that the Sony VTCs are getting very hard to find, what we need is a comprehensive list of what the capabilities are of the batteries available, along the lines of: battery name, size, mAh, Max Amp (both Continuous and Pulse).

As I was getting low on Sonys, i've just bought 4 x Samsung 18650-25R which are supposed to be good, I know the 20R were tested and actually okay up to 22A, but I haven't found any testing for the 25R.


EDIT: I have now on that German site linked to in the OP and according to them the Max is 20A for both those Sammys

Try Cell data. These are all the cells that three of us have tested.

IR is a lot higher for the VTC4 than I measure on my well used 10 I get mean of 12.1 m?, I will give you the Internal Resistances I have measured:

4  well used Panasonic NCR18650B I get mean of 43.25 m?
10 well used Panasonic CGR1865CH I get mean of 29.9 m?
2 (only half dozen cycles) Xtar 18500 both 19 m?
2 lightly used Efest red 18500 BT mean of 31 m?
9 Efest red 18350 are all over the place, both in IR and capacity

All measured on a ZB206 analyser & I try to test around 4 V, but some IRs will be a bit high as I have only had the analyser for a month and some readings are when fully charged so probably too high.

E: all the batteries were button top

[Deleted]

Nov 8, 2014 12:17:52 GMT Bob said:

The main problem facing us now is that the Sony VTCs are getting very hard to find, what we need is a comprehensive list of what the capabilities are of the batteries available, along the lines of: battery name, size, mAh, Max Amp (both Continuous and Pulse).

As I was getting low on Sonys, i've just bought 4 x Samsung 18650-25R which are supposed to be good, I know the 20R were tested and actually okay up to 22A, but I haven't found any testing for the 25R.


EDIT: I have now on that German site linked to in the OP and according to them the Max is 20A for both those Sammys

The battery buying guide is a good place to start. No Efest are listed there, much to the consternation of many at the time, but omitted for the same reason this thread was started. I personally don't buy Efest anymore.

Recommendations change so does the guide just need a refresh?

[thatguy]

Looking at the german graph provided by the OP, this relates to battery life, not to max safe discharge. Data I've found from reliable sources such as candlepower forums (the guy there test batteries correctly, and uses multiple batteries and multiple runs of tests on each), the max discharge of the 3100 purple efests seems to be 10A. The 20A stated by efest has been tested and seems to be safe as a pulse discharge rate, not a constant discharge.

Be aware that there may be safety issues with these batteries, but with the information currently available, I'd say be careful, but not bin them.

Quite honestly, I run two of these at 0.5 ohm with no issues at all. Not a hint of heat buildup which would be apparent if the batteries were being discharged too quickly. AWs tend to heat up more in my experience.

Take note of the OP's warning, but don't overreact by trashing batteries just yet. Perhaps sit them aside until more information comes through.

[Tom]

its bloody worrying is what it is.
im willing to bet a pretty large portion of people, even sub ohmers are thinking these are safe

[davetherayon]

It's concerning that Real People new to vaping will be watching youtubes by a certain nob'end whose name rhymes with Pee Way, and stack dodgy 2600 batteries expecting the result to be a cumulunonimbus in their living room, followed by no teeth.

[b1mble]

Nov 8, 2014 22:40:30 GMT VapingBad said:

Nov 8, 2014 20:30:25 GMT b1mble said:

Try Cell data. These are all the cells that three of us have tested.

IR is a lot higher for the VTC4 than I measure on my well used 10 I get mean of 12.1 m?, I will give you the Internal Resistances I have measured:

4  well used Panasonic NCR18650B I get mean of 43.25 m?
10 well used Panasonic CGR1865CH I get mean of 29.9 m?
2 (only half dozen cycles) Xtar 18500 both 19 m?
2 lightly used Efest red 18500 BT mean of 31 m?
9 Efest red 18350 are all over the place, both in IR and capacity

All measured on a ZB206 analyser & I try to test around 4 V, but some IRs will be a bit high as I have only had the analyser for a month and some readings are when fully charged so probably too high.

E: all the batteries were button top

Yes - I have my doubts about the reliability of the AWT charger's impedance measurements that are in some hitherto unknown units depicted as mR. IMO you need a 4 wire setup to measure internal resistance of batteries but the numbers given by the charger are better than nothing. Lab grade they are not.

[VapingBad]

Nov 9, 2014 8:42:00 GMT b1mble said:

Nov 8, 2014 22:40:30 GMT VapingBad said:

IR is a lot higher for the VTC4 than I measure on my well used 10 I get mean of 12.1 m?, I will give you the Internal Resistances I have measured:

4  well used Panasonic NCR18650B I get mean of 43.25 m?
10 well used Panasonic CGR1865CH I get mean of 29.9 m?
2 (only half dozen cycles) Xtar 18500 both 19 m?
2 lightly used Efest red 18500 BT mean of 31 m?
9 Efest red 18350 are all over the place, both in IR and capacity

All measured on a ZB206 analyser & I try to test around 4 V, but some IRs will be a bit high as I have only had the analyser for a month and some readings are when fully charged so probably too high.

E: all the batteries were button top

Yes - I have my doubts about the reliability of the AWT charger's impedance measurements that are in some hitherto unknown units depicted as mR. IMO you need a 4 wire setup to measure internal resistance of batteries but the numbers given by the charger are better than nothing. Lab grade they are not.

I agree and think that your spreedsheet is grate.  The analyser I have uses a 4 wires set up and was under £20 FT SKUs 883205, 1883213 & 1883210 not lab grade, but the best I could find for affordable money.