Lets talk about safety

[funnelclouds]

Hey everyone,

I know there are lots of blogs, forums, sites and places to go to talk about rebuilding and sub ohm safety but it has been hard for me to have all of my questions answered. like my main question i have had 2 2500 mah 3.7 v 35 amp Efest batteries vent at the top of the positive side of the battery, most people have been telling me that my builds are to hot and leaving it at that but the issue is that, my lowest build to date has on been .35 i cant understand how people can have .15 .2 etc builds and have nothing happen to their batteries i was thinking it could be a low quality mod i have a nemi clone that i got from a shop in town for 45.00 so i know its low q but is that enough to blow out batteries. i am not the most knowledgable when it comes to this and i think the people i have talked to either know that or learn it quickly and decide that im more of a waste of time then someone worth helping.

 

[Susan~S]

Just a FYI for you. Your Efest 35A batteries are only 20A continuous. This link is from Baditude (our resident battery/safety expert): Purple Efest Batteries not as Advertised.

Battery Basics for Mods
- choose the safest and right battery for your applications here. Includes a list of name brand, high-drain, safe-chemistry batteries with mAh & amp ratings in 18350, 18490/18500, and 18650 sizes.

Information Resources for Your First RBA

Explain it for the Dumb Noob: Ohm's Law calculations

 

[funnelclouds]

Just a FYI for you. Your Efest 35A batteries are only 20A continuous. This link is from Baditude (our resident battery/safety expert): Purple Efest Batteries not as Advertised

Awesome thank you

 

[retic1959]

Switch to Sony VTC 4 or 5 batteries and get them from a reputable dealer like RTD Vapors , .35 is within the safety margin for 30 amp continuous discharge batteries .

 

[Kaezziel]

Susan is absolutely right. And you can find a ton of info if you follow the link in my signature to Baditude's blog.
Also, I wouldn't blame the mod... even a cloned Nemi won't cause a battery to vent.
You say that your builds don't go below .35 ohms, but what are you measuring with. You need an accurate meter.
Your meter may be off calibration, your coil may have been a bit loose and shorted some other way (ie. touching the inside of the top cap or build deck)
There are a multitude of reasons that a battery could vent... it could have been previously overdischarged and damaged internally...

Bottom line is, it will be very difficult for any of us to pinpoint exactly what went wrong to cause your batteries to vent... but we would be most willing to help you figure it out.

*edit*
Just wanted to add... at 0.35 ohms, you'll pull at most 12A
But at 0.21 you would pull 20A... that is only a 14 hundredth of an amp difference...... a VERY small margin of error...

 

[EBates]

Maximum Continuous Current for the Efest is 20 not 35 amps. 35amps is the Pulse Rating. Just so you know.
.35 ohms @ 4.2 volts is 12 amp current drain and IMO a safe build.
.15 ohms @ 4.2 volts is 28 amp current drain and IMO a unsafe build.
(V/R=I)
So, I think you can see that a difference of .2 ohms can be a problem. Please use a good resistance meter and be careful of shorts.

 

[Susan~S]

How to Spot Fake Sony Batteries



Only buy batteries from a reputable supplier (not ebay or Amazon) as there are many counterfeit batteries being sold. Here are several reputable battery suppliers in the US.

* RTD Vapor
* Illumination Supply
* Lighthound
* Orbtronics

 

[JeremyChess]

Sure - Always remove your battery while installing new coils. NUFF SAID ,,,,

There are Sony clones out there .. They don't provide nearly the amps advertised . I bought 4 from a Haji Mart E cig / head shop in Sacramento .. Burned one up in a Day .. So I tested all of them and each was only putting out 19 Amps except the dead one It was 0

 

[eratikmind]

The exception to the Efest being the purple 2100mAH, which is a 30 amp battery. It's a rebranded Sony VTC4.

 

[JeremyChess]

The exception to the Efest being the purple 2100mAH, which is a 30 amp battery. It's a rebranded Sony VTC4.

Damn skippy .It is not OFFICIALLY a Sony Re brand but it is the exact duplicate of the Sony VTC4 . The VTC5s are getting hard to find .. I heard a rumor Sony is calling it quits but no one knows anything , You know how those corporate hooligans are .. Secretive about everything

 

[Susan~S]

Damn skippy .It is not OFFICIALLY a Sony Re brand but it is the exact duplicate of the Sony VTC4 . The VTC5s are getting hard to find .. I heard a rumor Sony is calling it quits but no one knows anything , You know how those corporate hooligans are .. Secretive about everything

The Sony VTR series batteries are now being made in a facility in the Phillipines after the original plant in Japan was damaged by the nuclear accident. Hopefully availability will change once their new factory in the Philippines is up and running at 100% capacity.

 

[funnelclouds]

all of these post have helped exponentially this very informative i really appreciate it all

 

[funnelclouds]

Susan is absolutely right. And you can find a ton of info if you follow the link in my signature to Baditude's blog.
Also, I wouldn't blame the mod... even a cloned Nemi won't cause a battery to vent.
You say that your builds don't go below .35 ohms, but what are you measuring with. You need an accurate meter.
Your meter may be off calibration, your coil may have been a bit loose and shorted some other way (ie. touching the inside of the top cap or build deck)
There are a multitude of reasons that a battery could vent... it could have been previously overdischarged and damaged internally...

Bottom line is, it will be very difficult for any of us to pinpoint exactly what went wrong to cause your batteries to vent... but we would be most willing to help you figure it out.

*edit*
Just wanted to add... at 0.35 ohms, you'll pull at most 12A
But at 0.21 you would pull 20A... that is only a 14 hundredth of an amp difference...... a VERY small margin of error...

i have a cheap ohm reader but i also have a multimeter that i have been using as of late because after i had vented the second battery i got real freaked out. you mentioned shorting. I am now thinking, after reading all of the comments and using the link provided, that my atty was shorting i always had a screw coming loos and i wouldnt figure it out for a good while. I have checked everything else, there is no sign of shorting in the mod, i know there are many other possibilities but in your opinion would that be a pretty safe bet as to the reason of the venting?
Thanks for you advice i really appreciate it

 

[InTheShade]

For those interested, the Samsung 20R (22 amp) and 25R (20 amp) are decent replacement batteries for those struggling to find the VTC series. Both are available from Illumination supply for around $8-9 each.

 

[2naphish]

For those interested, the Samsung 20R (22 amp) and 25R (20 amp) are decent replacement batteries for those struggling to find the VTC series. Both are available from Illumination supply for around $8-9 each.

that's why i am using the 25r in my BCV mods and .4 - .5 ohm builds. they work wonderfully and the top end of the voltage seems to last a bit longer than the Sony's. i will continue to use them until i am as sure as i can be that i am getting the real deal on the Sony's. JMO

 

[Boiler]

 

[CoilMeister]

Mnke or Sony vtc's

 

[AzPlumber]

Sure - Always remove your battery while installing new coils. NUFF SAID ,,,,

There are Sony clones out there .. They don't provide nearly the amps advertised . I bought 4 from a Haji Mart E cig / head shop in Sacramento .. Burned one up in a Day .. So I tested all of them and each was only putting out 19 Amps except the dead one It was 0

I'm curious how you go about testing a battery for how many amps they are putting out.

 

[funnelclouds]

I'm curious how you go about testing a battery for how many amps they are putting out.

i would use a multimeter although i have not done that with mine

 

[AzPlumber]

i would use a multimeter although i have not done that with mine

You can measure how many amps a device is drawing but you can't measure how many amps are in a battery.