Batteries! in general / stamina of..

[purkle]

Hello ya vaping friendlies! sorry.. me again.. with MORE questions!!

Once again something fairly simple (buying a couple of batteries for my imminent mod ownership (yas!!!)) has become oh-so-complicated! But probably just because, well, that's how my brain makes it, haha!  I've been reading a lot of stuff on Torchy's website, very interesting, total SHOCK HORROR about the state of those Ultrafire batteries which were just re-cased old defunct / tiny wee batteries!! that's mental! However the bit that was really interesting was the voltage capacity graphs showing how various batteries behave at a constant current discharge.  I'm looking specifically at the varying performance of 18650 batteries but thought what I'm not sure about would probably be relevant to anyone looking for any kind of battery probably..  Defo gonna buy from Torchy as he gets such great feedback from yous, plus he definitely knows his stuff & is honest about the facts it seems so nice one for the recommendation    Blaa, blaa, sorry I'm terrible for wittering on!

So these graphs.. It seems to me that for vaping you want a battery which is not JUST going to last as long as possible, but also stay above a certain voltage (say, 3.5v) for as long as possible?  If this is not correct then please somebody jump in here & stop me digging an ever deepening hole ! But what I was surprised about is that some lower capacity batteries seem to completely blow other higher capacity batteries out of the water!
For example, Sanyo 2600mAh (18650's) start at 4.2v & steadily decrease in voltage where they cross my 3.5v fence at 2600mAh.. so that's a really great capacity but also a useful one because at nearly the end of it's power it's still delivering a decent voltage (& therefore I assume Mr.Vaper is happy).  Whereas (& this is totally not the most extreme example by any means, but another decent battery I think) the SenyBor 2800mAh protected batteries start similarly but cross the 3.5v fence at just under 1500mAh?!!!

Here's a list of a few of them, from the best downwards (judged by my possibly stupid fence rule..!) ('P' = protected)
Sanyo 2600mAh:         start 4.1v, cross the 3.5v fence @ 2400mAh
Torchy 2600mAh:         start 4.1v, cross the fence @ 2400mAh
Torchy 2400mAh:         start 4.1v, cross the fence @ 2400mAh
SenyBor 2600mAh 'P':  start 4.05v, cross the fence @ 2350mAh
Sanyo 2800mAh:         start4.05v, cross the fence @ 2300mAh   *but meant to have a higher capacity than Sanyo 2600mAh!
Lezyne 2400mAh 'P':    start 4.0v, cross the fence @ 2050mAh
Panasonic 3100mAh:    start 4.05v, cross the fence @ 1750mAh
AW 3100mAh 'P':         start 4.0v, cross the fence @ 1650mAh
Torchy 2800mAh:         start 3.95v, cross the fence @ 1550mAh  *but meant to have higher capacity than Torchy's 2600mAh!
Torchy 2800mAh 'P':     start 4.0v, cross the fence @ 1500mAh

Ok I'll stop OCDing everyone out now, I'm sure you get what I mean.  They're all quality batteries, but they differ a lot & the actual stated capacity doesn't seem to mean much, even two different batteries by the same company (e.g. Sanyo) can outperform each other where the lower stated capacity can run at a higher voltage for longer than the higher stated capacity one.  The Xtar batteries on Torchy's site looked great, but again the 2600mAh 'P' looks a lot better than the 3100mAh 'P'!!  Some of the actually poor quality ones were REALLY bad: e.g.

Ultrafire 3000mAh (red/white):  start 3.95v, cross the fence @ 550mAh (!!!)

So obviously it's important to have a good look at the stats, & aye I'm aware that probably a difference in a couple of mAh or whatever won't be too noticeable, but according to some of these it could make a big difference if I'm not careful about choosing.  Can someone tell me if how I'm looking at these graphs is useful or am I 'doing a politician' and reading something from the stats that really isn't what is actually the case?

If what I've written is a useful comparison, then the best 18650 batteries were Sanyo 2600mAh, Xtar 2600mAh 'P', and Torchy's 2400 & 2600mAh.  And all of these were better than any make of battery listed as anything over 2600mAh capacity?! Aaaaahhhhh, brainfry!!!!

(Thanks in advance.. sorry about my wittering!!)

[giles]

Have you seen this guy's stuff purkle?

[DiscoDes]

Cutting through all that and to keep things simple, we have many users so can talk about what USERS have found to be the best I'll list a few here that people use and comment are good :

Efest IMR's all sizes
Panasonic CGR18650CH - 18650
AW IMR's - all sizes
Torchy IMR's - All sizes

This is NOT an exhaustive list!

Generally use non protected or IMR's in VV / VW mods with electronics in (Vamo, VTR, SVD, Zmax ect) as protection is built in to the Mod or a mechanical mod with a Kick unit.
Use IMR "Safe Chemistry" in non protectected mechanical mods - or protected batteries AFTER checking the protection can carry enough current to run the mech mod with your set-up.

Hope this helps.

[charon]

purkle Like the man says.^^^...... Just do yourself a favour.. don't over cook your search.

Generally use non protected or IMR's in VV / VW mods with electronics in (Vamo, VTR, SVD, Zmax ect) as protection is built in to the Mod or a mechanical mod with a Kick unit.
Use IMR "Safe Chemistry" in non protectected mechanical mods - or protected batteries AFTER checking the protection can carry enough current to run the mech mod with your set-up.

[purkle]

Thanks Giles & DiscoDes (great name btw!); yeah the video was useful actually, a good link, nice one. Although, really, why doesn't anyone just write stuff down anymore?!! But it reminded me about C ratings, very helpful. Didn't realise previously that C rating & mAh capacity is inversely proportional, that explains a lot

I can't find any reference to C rating or discharge rate on most of the battery websites though, even good components sites. EVEN Torchy doesn't seem to list C rating as far as I can see..! And it does seem to be important, I can't just ignore it, can I?

The vid still didn't really explain the differences in voltage drop-off & the consistency of batteries, although I spose I can just keep reading & researching.

Maybe you're right DiscoDes & I should just buy the brands that other people say are good! I don't want to become a batterygeek just for the hell of it, I'm meant to be studying chemistry haha, not physics! (Although all relevant I spose..) I'm just one of those people who need to always understand everything, I'm not good at accepting stuff if the info isn't there or if I don't get it! however I don't have a couple of years to learn & decide which batteries to buy haha! So I guess you're right...

Thanks Guess I'll just need to go for it & also keep researching

[purkle]

& thanks charon too! ayee, I've obv got too much time on my hands lol!!

[boyofford]

You could ask torchy himself, he is on the ukvapers website and can also get discount on his batteries there.

I asked him stuff relating to sub ohm battery recommendations and he was very helpful.

[Brambles]

purkle,
You are certainly on the right tracks with your investigation into batteries.
The reason some higher capacity batteries are appearing lower is because some have a max charge voltage of 4.3 volts and not 4.2. Also to get the full rated capacity some have to be discharged right down to 2.8 or lower volts. So quite rightly as you have done is to look at the actual returned capacity at the voltage you will use it down do. For a mech mod then you need the voltage drop to be as level as possible. For an electronic mod with voltage boost then you need to use the cut of voltage which is often 3.2 or 3.3 volts and find the capacity at that point.
The panasonic 3400 comes out tops but not by that much and you pay a lot for them. If you need the capacity fine but you are paying a lot a couple of hundred extra mAh.

Mid range capacities around 2600, the Sanyo's are good if you pick the right one. Also LG have a good battery as well.
I did a write up and posted on battery results a while ago, but i have edited the posts to say ignore because I made some stupid fundemental mistakes. However the conclusions in it are still fairly valid as to what are the best batteries for capacity. Since I have re-looked and corrected on my Excel spreadsheets but not updated my posts yet - forgot all about it.
Maybe now is a good rime for me to look back at my data collected and update it all.

If you really what to get into this yourself then you will find this guys test results extremely useful. www.dampfakkus.de/liste_akkus.php

If you open up the chart and results of tests at various amps you can see the graphs but be careful as they are a bit misleading as the x-axis is time not capacity although somewhat related.
Below the charts he lists the actual capacity discharged to various voltages and that is what is most useful.

There is always a trade of when a battery capacity increases, or max current it can supply increases and to get improved current and capacity batteries cost more.
In a mech mod you should really use protected batteries, but in Electronic mods often unprotected. So you then also should look at what safety is built into the battery. Some have built in PTC devices in the caps to give protection against short circuit, some have internal fuses as well and some batteries have, by their technology and chemistry, safety built in.

I recently bought some Sanyo UR18650FM batteries ( red with pale blue insulator ring on cap) and capacity has proved to be excellent and voltage stays up well and returns good capacity down to 3.6 volts and very rapidly falls from 3.6 to 3.2volts. And, they were relatively cheap to buy. Good choice for a mech mod when bought as a protected version as well as electronic with unprotected version.

I shall leave this scribble at that...and look tomorrow if I get a chance and make a more sensible contribution, but hope this all helps you a little.


Edit - cannot believe the number of spelling mistakes I made a above - think I have corrected most!!

[Brambles]

If you want a good example of a battery where specs and graphs matter, look at the link I gave for battery tests at the Panasonic NCR18650 2900mAh and the CGR 18650CG 2250mAh at 5 amps discharge. The NCR gives 35mAh down to 3.6 volts, and the CGR gives 356mAH down to 3.6 volts. This is 3.6 volts under a 5 amp loads and only applicable for high power vaperers, but shows how the specs are important. For a normal user at say 2 amps then the results will be quite different.

[purkle]

Thanks Brambles, that's just the kind of info I was looking for, thanks very much! I'm glad I was on the right track with the voltage drop-off as I've got my first mech mod on it's way..! (which will need to last me some time!) I kinda had to make a decision & just went for Efest 2250mAh 18650's from Torchy, almost wish I'd waited now but I'm sure they'll be ok for a while at least, as long as they're safe enough! They're not protected, but they are IMR so I don't think it should be too dodgy.. (she says, hopefully!) They're 3.7v & discharge up to 10A, but I'm only currently using 1.8? & 2? resistances which I gather will not push the battery to it's max & get too tricky. I've got a nitecore i4 charger on it's way which shouldn't overcharge them & charges at a safe voltage. Also because they're IMR they shouldn't be able to overheat I think?

From what I revised yesterday, 3.7v / 10A discharge = the minimum safe resistance 0.37?; although I'm sure I won't be discharging at anything like 10A, so I'm not entirely sure what to make of that.. 3.7v / 2A (which you mentioned might be a more normal load) = 1.85? so possibly I'd be better sticking to my higher resistance coils..

I'm thinking a good amount of power might be 10W, so 10W / 3.7v = 2.7A; if I'm drawing a current of 2.7A then the minimum safe resistance would be 1.37?.

The only bit I'm not sure about (which I now want to find out since I've not bought protected batteries..!) is how you draw a lesser current out of a battery which can discharge 10A. If you've got a clue what I'm asking then that would be great.. if I'm just getting all gobbledegooky then no worries But thanks anyway for the links & very useful info I'll also get a hold of Torchy methinks as maybe he'll recommend a different battery as he won't have sent mine yet, I didn't realise he was on UKVapers boyofford so thanks thats helpful too!

Cheers, Lauren

[purkle]

Ok maybe I'm getting there... so using a higher resistance coil will draw less current from the battery, but also mean less power (&therefore vapour); and using a lower resistance coil will do the opposite, but the 'safe' limits of the battery may be challenged.. I can test the voltage of the circuit using my multimeter, so say the voltage reads 3.7v and I've got a 1.8? coil in, then I'm drawing 2.06A, which is surely a nice safe current from a battery that can give 10A? If that's correct then I'll be fine eh?!! LOL! this is hilarious, sorry everyone! back to school! xx


edit: I found this as well; (AkkuDB link showed me that the Efest's are (I think) Panasonic in that battery) www.e-cigarette-forum.com/forum/super-t-manufacturing/295446-load-testing-panasonic-imr-18650-2250mah-cgr18650ch-stock.html
& the graph looks to show (although vv small writing!) voltage in relation to AmpHours (same as capacity x 1000 I'm assuming) which shows a really good voltage drop-off for them, so I'm satisfied I've got a good yin, just not totally sure about the safety & what kind of resistance to use.. all learning!!

[boyofford]

With a 10amp max discharge your good to use down to 0.4 ohms in theory.. in practice I personally leave a bit more of a safety margin and do my coils around the 0.7 ohm mark though.

[xs2man]

All very technical, lol.

I have the Panasonic CGR18650's and the Sony VTC 4's. Both are excellent batteries, and regarded as among the best you can get. I am very happy with both of them anyway.

My 18350's are Ultrafires though, and I have had no issues with them as yet.  I may well replace them with AW's or Torchy batteries at some point though, but just now they are working well.  And I barely use 350's.

[PipeBomb Jon]

Well done DiscoDes for keeping things clear and simple. It's good to be concerned and do your research, but at the end of it, I'm sure you'll find that its actually more simple than you first thought. Following what others use seems to be the best advice. As I see it, most manufacturers of mods recommend using AW IMR's for their devices and from what I understand, most people end up using these batteries. AW seem to be more 'honest' than most in regards to their mAh rating. I'm currently using Efest from Torchy, if you haven't found out already, you can get a good discount from Torchy when buying through UK Vapers.
On your earlier post Purkle, you stated, 'because they're IMR they shouldn't be able to overheat I think?'. IMR's will overheat in certain situations and vent gases (generally only in certain situations if used without care, by the user), but not explode. That's why you'll have venting holes placed on the overwhelming majority of mods. The majority of problems that I've seen talked about, is when users are not present when charging batteries, such as putting them on charge and going to the shops, or going to sleep with a mod in the pocket, without the safety switch engaged. So it's advisable that you are always present when the batteries are being charged and don't overcharge your batteries.
For battery geekiness, head along to batteryuniversity.com

[Romney]

Feb 6, 2014 17:28:34 GMT xs2man said:

All very technical, lol.

I have the Panasonic CGR18650's and the Sony VTC 4's. Both are excellent batteries, and regarded as among the best you can get. I am very happy with both of them anyway.

My 18350's are Ultrafires though, and I have had no issues with them as yet.  I may well replace them with AW's or Torchy batteries at some point though, but just now they are working well.  And I barely use 350's.

Hi xs2man,noticed your post on Sony VTC 4,s.Are they good? I was going to buy a couple for my SVD,are they unprotected? I believe unprotected is the best for VV-VW,looking at Forums.