Help choosing an 18650 battery (Sigelei 20W)

[makeyourself]

Right I've read just about everything I think I possibly can read about batteries for now but still feel I could do with some advice before I make a decision. Basically I was going to get a Panasonic 3400mAh NCR18650B but then I realised that this is an unprotected battery, unprotected ICR I think. My main priority is safety followed by something with the maximum possible mAh. I don't need high drain because I'm not planning on doing any sub-ohm any time soon. So from all what I've read so far IMR is the safest option for a device like the Sigelei 20W but the highest capacity I've been able to find so far is the Efest 2500mAh. Quite a big discrepancy between that and 3400mAh. Now there very well may be other decent ones out there with similar or higher capacities that I just haven't come across so if there is could somebody please point the model numbers out to me? If not then I assume its something inherent in the chemistry of IMRs and I'll just have to put up with it!

Just a couple of other things, it just so happens that the Efest 2500mAh is a high drain battery, maximum discharge current is 35A. Am I correct in assuming that this just makes it safer to use even if I don't need the extra current?

Final thing, I've seen a couple of remarks about certain batteries being very tight fits and squashing/crushing the springs in mods (even though they are the are the correct form factor, e.g. 18650), how do I tell which batteries might do this?

 

[Baditude]

IMR batteries are inherently high drain and safe chemistry batteries.

By all means, do not use a protected ICR battery in ANY mod (in my opinion). In this day of modern battery technology, ICR batteries are antiquated and should be considered obsolete in mods. They had their day in the sun, and that day has come and passed.

Are Panasonic/Orbtronic NCR18650 3100/3400mAh batteries any good?

I don't know the recommendations nor the requirements for DNA devices, but as they still use regulated circuit boards to produce high voltage, I don't see why they would be any different than ordinary regulated mods. At the very least you'll want a high drain battery. Perhaps even a high-amp high drain battery. I'd say the Sony US18650VTC5 2600mAh 30A battery would be your best option. Another possible alternative for a higher mAh rating would be either the Panasonic/Orbtronic NCR18650PD 2900mAh or NCR18650PF 2900mAh 10 amp batteries (unprotected versions).

Because of battery chemistries as we know it today, you can either have a high-capacity (mah), low-drain, low amp, unsafe battery (ICR) or a high-drain, high amp, safe chemistry battery (IMR). You can't have your cake and eat it too. Which one sounds best to you?

 

[makeyourself]

The second option but I'm a bit confused Baditude because you have linked to one of your posts in which you advise against using ICR/IMR hybrids. But the batteries you have recommended above are all hybrids. I know there are several variations in hybrid chemistry so maybe that's where the differences lie?

What I do know about the Sigelei 20W is that pbusardo tested it with an oscilloscope and it appears to output flat DC, no PWM, which is apparently the same as DNA20s:
https://www.youtube.com/watch?feature=player_detailpage&v=7jxTyMCyo-g#t=1575

What do you think about the Effest 2500mAh 35A IMR?

 

[Baditude]

The second option but I'm a bit confused Baditude because you have linked to one of your posts in which you advise against using ICR/IMR hybrids. But the batteries you have recommended above are all hybrids. I know there are several variations in hybrid chemistry so maybe that's where the differences lie?

There are variations in the chemistry of the different IMR-hybrids on the market. IMR-hybrids are a mixed-chemistry of ICR and IMR chemistries. As I will show below, not all IMR-hybrids are high drain batteries.

The 3100mAh & 3400mAh Panasonic/Orbtronic models' hybrid chemistry is so heavily weighted toward ICR that they may as well be practically considered an ICR - they are not considered to be high drain, have a high internal resistance, and have a lower than typical amp rating (only 6.8 amp vs the typical 10 amp). Orbtronics had a disclaimer for their version that said these were not recommended for e-cigarettes but only for flashlight applications.

On the other hand, the NCR18650PD & NCR18650PF models by Panasonic/Orbtronics are IMR-hybrids which still retain a high drain ability, have an low internal resistance, and have a 10 amp rating. They currently have the highest mAh rating for a high drain IMR-hybrid battery (2900mAh) on the market.

What I do know about the Sigelei 20W is that pbusardo tested it with an oscilloscope and it appears to output flat DC, no PWM, which is apparently the same as DNA20s:
https://www.youtube.com/watch?feature=player_detailpage&v=7jxTyMCyo-g#t=1575

That may well be so. The same thing can be seen when you put a Provari on an oscilloscope (flat line) and it has a circuit board which uses pulse regulation (pulse width modulation) using 800 Hz PWM.

The majority of other circuit boards use PWM at a 33.3 Hz - 46 Hz frequency ("rattlesnake effect"). http://www.e-cigarette-forum.com/forum/variable-voltage-apv-discussion/488840-rattlesnake-effect-why-cheapo-vv-exception-itaste-mvp-dont-vape-same-provari-dna20d.html

What do you think about the Effest 2500mAh 35A IMR?

No comment presently. Much of the specification data from Efest has been overstated in the past, to be found to be inaccurate when actual bench testing is done by independents. I read of one such test comparison of the above battery and it said that it tested out to be only a 20 amp battery. I don't have a link to that but I'm sure I read it in this subforum.

 

[makeyourself]

Well I think I might go for a Sony US18650VTC5, I can find the 2900mAh Panasonic ones for sale over here (in the UK) but only from web sites I've never heard of. I'll probably just buy one Sony for now and might get a higher capacity at some point later depending on needs. I don't suppose you happen to know if the US18650VTC5 comes in a protected version (i.e. hopefully not)? The reason I ask is that the vendor hasn't stated whether the version that they are selling is protected or unprotected. Even the Sony datasheet isn't that clear about it, at least not clear enough for me:
http://www.intaste.de/community/dtf/technical_information.pdf

 

[Marc411]

I'm using the VTC5 and the Efest IMR Purple 18650 35A in Sigelei 20W and both perform excellently.

 

[makeyourself]

Well I managed to get a VTC5 ordered so thanks for all the help. Also got the mod and Nitecore charger on its way so all sorted now!

 

[GeorgeWachsmuth]

Good choice! I use VTC4s and VTC5s in mine and they work great!