Lithium batterys explained(ish)

[Crossbow]

Credits first - most information, and all the graphs were from http://www.mpoweruk.com/

As most of you already know, Ecigs use Lithium - ion batteries. The main reason for this is the high voltage, the way in which they discharge and their high energy density (a small battery holds a lot of power)



As you can see, after an initial steepish drop, discharge voltage remains fairly steady, up until the end, where it plummets.
Lithium batteries also hold charge well - most rechargeable batteries will self discharge in an annoyingly short period of time, typical self discharge rates for common rechargeable cells are
    * Lead Acid 4% to 6% per month
    * Nickel Cadmium 15% to 20% per month
    * Nickel Metal Hydride 30% per month
    * Lithium 2% to 3% per month
This isn't quite the whole picture however - most rechargeable batteries only have reversible self discharge - Lithium batteries actually permanently lose capacity over time! This is why ecig batteries are relatively short life items
The rate of this loss is largely temperature based.... bad news for hot titans!




The rate a battery is discharged at also affects its capacity. This is expressed as a C - rate, with 1C being a one hour discharge time, so a battery discharges in an hour at 1C, 30 mins at 2C and 2 hours at 0.5C. High discharge rates significant damage battery life, bad news for Uber heavy users like me.






The same C rates, and their effects apply to charging (to some extent, and to keep it simple) which is why most chargers take several hours.

Lithium battery chargers are generally constant current - constant voltage, where initially a constant current is applied (resulting in an increasing battery voltage) which is then switched to constant voltage when the voltage reaches 4.2V (as overcharging lithium batteries is BAD)





Its also possible (and I haven't checked, but I imagine this is how ecig chargers work) to charge using constant current ONLY. In this case, charging stops at the end of the flat green part of the graph above. This reduces the capacity of the battery to about 80%, but simplifies the charger and usually slightly extends battery life, and of course reduces charge time

Most commercially sold Li batteries have a protection circuit (and that includes all ecig batteries) which does 2 things - it prevents an input voltage of more than 4.2V being applied (to prevent the likes of this happening) and to prevent it being discharged too far - if the cell voltage drops too far, the chemical reaction becomes irreversible, and the battery wont hold much if any charge.
Some of the larger Lis (such as 14500 and 18650) may, or may not be protected - if they aren't it's vitally important to use a protected charger!

[spiraller]

Fantastic information cross, I'm making this a sticky and referencing it in the FAQ! Hope that's okay

[Crossbow]

Of course

[SludgeVanDiesel]

I wish I was more technical.

[~K~]

Cross lost me lmao as that is to tech for me 

[moog]

I wish I was more technical.

LOL..Same here....

[Crossbow]

I wish I was more technical.

Me too

[prof beard]

On the subject of "unprotected batteries" - these are NOT lethal man-killing devices (as some on the dark side would have it) PROVIDED (as has been said) a proper charger is used.  It is also preferable to use a slow charger rather than a fast one for these batteries.  The SD uses unprotected batteries and (as trog has said) you "could" overcharge them with the wrong chargers - however he has also said that there is no realistic likelihood of someone dangerously depleting such a battery in an e-cig as the atomiser stops working before a dangerous level of battery flatness is reached

[IYFZZZ]

If the rate of loss is largely a  temperature issue then why encase the batteries  in a solid round casing? In my field of expertise when you have a heat sensitive item you would not use a flat surface ( I know the ecig is a round cylinder) but by adding very small ridges you create more surface area hence more heat can be dissipated quicker.  The ridges also take the heat away from the body of the battery this would also help.

[Crossbow]

Most of ecig design is based around the cigarette look, and of course, having a metal body and connector provides heat conduction between the atomiser and battery. Its the heat from the atomiser thats the issue - unless a battery is already FUBAR, it shouldn't generate significant internal heat.
That said, on a small battery, the biggest issue is likely to be charge and discharge rates, atomisers can draw anything upto 1000mA, which is about a 5C discharge rate. Its intermittent, so its not as bad as constant discharge, but its not going to help matters.

[Larry]

I notice these e-cigs are consumable so people have to replace batteries and atomizers.  That seems wrong to me.  If I could unscrew the tip and drop in a couple of AAA batteries I'd be happy but what's with the atomizer burning out?  Maybe someone will make one that has an indefinate lifespan.

[Angela]

I agree Larry, but unfortunately it seems to be going the other way with disposable 'cartomisers' (a combined atty and cart).  I will resist that at all costs!

[Crossbow]

Thats one of the reasons I bought the Janty Stick Replacement batts for £2.50.... hell yeah!

[moog]

or even cheaper at dealextreme....

[g-grandad]

Is there something in the design of lithium batteries that limits their capacity ? AAA NiMH rechargeable batteries are available at 1000mAh these days.

[Crossbow]

In theory, the newest NiMH have about the same energy density as Li-ion, so they should be comparable sizes, I think that cost is probably the limiting factor for Li capacities, as Li is about 4 times more expensive (and thats the industry cost). As has happened with NiMH, larger capacity Li batteries will probably start appearing as price drops

[FireSprite]

Is there something in the design of lithium batteries that limits their capacity ? AAA NiMH rechargeable batteries are available at 1000mAh these days.

Ah but lithium batteries have 3 times the voltage of NiMH. A battery's energy is measured in mWh and to get that you multiply the mAh by the volts. So a 1000mAh NiMH (1.2V) has 1000 x 1.2 = 1200 mWh, and a 360mAh lithium (3.7V) has 360 x 3.7 = 1332 mWh.

[moog]

Welcome to the forum Firesprite...

[~K~]

Welcome to the forum Firesprite 

[Larry]

Totally Wicked is selling a 5 pack of batteries and atomizers for both the 901 and the Titan.  I don't need batteries right now but I will in the near future I think so if I bought the 5 packe and kept them fully charged but didn't used them at all, would they degrade on their own and eventually become usless or would I be better off buying them as I need them?

[Crossbow]

if I bought the 5 packe and kept them fully charged but didn't used them at all, would they degrade on their own and eventually become usless

The best answer I can give to that is... kinda
Lithium batteries (apparently) store best if less than fully charged, and if stored cool, don't drop off terribly fast - if you have a look at this graph...

You can see that a battery at about 20 deg C will lose about 10% of its capacity in 12 weeks - not exactly a huge problem.
Based on what I know (and I'm no expert) I'd say that if you part charge them after testing (give them 10 mins or so each) and store them cool, the money you save will far outweigh the capacity loss

[prof beard]

As far as I'm aware all e-cigs use lithium batteries

[moog]

Cheemiss...checkout our FAQ section at the top of the forum.....click....most of what you need will be there....welcome to the forum...

[Crossbow]

Cheemiss...checkout our FAQ section at the top of the forum.....click....most of what you need will be there....welcome to the forum...

ALways a good start - and if you haven't already ordered, don't
Bear in mind that a company that employs sales reps will almost alwys be more expensive than one that sells direct. Also bear in mind that there arent actually that many models of E-cig, so theres a very good chance that any brand name is available elsewhere, and often much much cheaper.

As fas your question goes - any cigarette shaped E-cig will have a battery not significantly different to any other (other than disposable ones), they're much the same.

[MrMylesGuy]

So is it possible to say... take apart a titan battery and drop in say a new AAA? 

I think if e-cigs are goign to catch on they can't be this disposable.  Something dies I have to wait for my order to come online, I can't just pop in a new battery. What is it about atomizers that kills them?  They are just metal heating up.  Seems like there should be an easy fix. I realize these companies probably want you to keep buying from them, but I would much rather pay a premium for a replaceable AAA rechargable and a long lasting atomizer.

[Larry]

 I'm afraid an AAA battery won't be able to power the atomizer, in fact, not even two of them will because that would only be 3 volts total and the batteries with our cigs are like 4.1 volts at a full charge.  Three AAA batteries would give you 4.5 volts which might be too much so you might need to add an inline resistor to cut the voltage down a little before the atomizer.
The coil in the atomizer is thin so the low voltage of 3.6 to 4.1 can work with them.  If the coil was any thicker, You'd need higher voltage to heat it up and get vapor from it which means you'd be carrying around a bigger battery  You can fashion an atomizer that would last for years if you plan on hooking up to a car battery.  Look at an electric burner on a stove and how thick the ni-chrome is.  Yes they last for years but they're thick and have to be plugged into a wall outlet to work.  Not even a car battery would last long with a draw that great. 

[DaveDzRochNY]

Lithium batteries (apparently) store best if less than fully charged...

OK, so...

Say Somebody buys a HUGE stash of batteries and they arrive partially charged.
Should Somebody deplete the charge (down to flash mode) before storing them
away and then bring them into use only as needed when old ones bite The Big One?

Signed,
Somebody

[Crossbow]

Say Somebody buys a HUGE stash of batteries and they arrive partially charged.
Should Somebody deplete the charge (down to flash mode) before storing them
away and then bring them into use only as needed when old ones bite The Big One?

Nope, best to leave them part charged, otherwise they may tip over into 'too flat' while they are stored, and you have a huge stockpile of metal cylinders

I would much rather pay a premium for a replaceable AAA rechargable and a long lasting atomizer.

Try a Janty stick (it takes cheap 10440 batteries) and combine it with a 5 pack of 801 atomisers from TW. 801 atts are pretty reliable, and 5 ought to last a loooong time

[jonuk76]

Hi Crossbow, do you (or anyone else for that matter) know much about the difference between Li-Ion and LiFEPO4 batteries, and their respective chargers?  LiFePO4 (Lithium Iron Phosphate) batteries are apparently much safer than Li-Ion's. They don't have a tendency to explode or catch fire.  They also have longer service life, but on the downside don't hold as much power as Li-Ion's.

I recently got some Tenergy LiFePO4 3v protected batteries which came with a specific charger for them.  I also ordered some spare 3v Li-Ion batteries (1000 mah rated CR123A's) from DealExtreme. I assumed at the time I'd be able to charge them with the Tenergy charger, but now I'm not sure. I'm a bit wary of trying it and seeing... Any thoughts?

[Crossbow]

My (quite possibly flawed) understanding is that LiPo are much safer, but the chargers aren't compatible - I'm not sure why, especially in the case of batteries with the same voltage (and it's too far past beer oclock to research it now )

[jonuk76]

Thanks for that I don't think I'll try them on the charger I have. If in doubt, don't do it seems to be a pretty good plan as far as lithium batteries go    A suitable charger from DX is pretty cheap anyway.

BTW, I believe Lithium Iron Phosphate and Lithium Polymer are different types. Lithium Polymers (LiPo) do explode as can be seen here http://www.youtube.com/watch?v=z3o_2mwRPdw

[magestorm]

Yes, current setups do not allow for one to get regular batteries and pop them in.  They are meant to be about the size of a ciggy.  Now, is it POSSIBLE?  Yes, it is.  The attys should be able to accept 4.5v from 3 AAA batteries.  You might need to drop in a resister to drop the voltage down to 4V.  Or, getting NiMH AAA, at 1.25v, should bring it to the low end of where it needs to be. 

Look in the mods area, and you'll find several mods.  Personally, I'd love to see one made from a recycled iPod, with one of THOSE batteries wired up and ready to serve.  You think you get long battery life listening to music, just wait till you try the new iVape 

But, if you know how to do some basic electronics, it's not hard to build the guts of a mod. 

[moog]

I thought this is an interesting link for why e-cig batteries don't last very long......click

[trog100]

Try a Janty stick (it takes cheap 10440 batteries) and combine it with a 5 pack of 801 atomisers from TW. 801 atts are pretty reliable, and 5 ought to last a loooong time

we have a sweet little cigarette sized manual  switch device that takes a cheap 10440 battery... way better than any janty stick... he he

sadly they are not ready for market yet.. they will be tho.. we just need to get them made.. we have the working prototypes..

basically they are about as near cigarette sized as possible whilst still taking a replaceable lithium cell.. they should have the same run time as the JS.. but be based around a more sensible size atomizer..

trog

[trog100]

I thought this is an interesting link for why e-cig batteries don't last very long......click

now you know why i got banned from the place moog... he he

trog

[Crossbow]

Try a Janty stick (it takes cheap 10440 batteries) and combine it with a 5 pack of 801 atomisers from TW. 801 atts are pretty reliable, and 5 ought to last a loooong time

we have a sweet little cigarette sized manual  switch device that takes a cheap 10440 battery... way better than any janty stick... he he

Funnily enough, my 3rd stick has keeled over, and my main vape is a Garry Dibley 10440 torch mod

[Larry]

Funnily enough, my 3rd stick has keeled over, and my main vape is a Garry Dibley 10440 torch mod

What's happening to your sticks anyway?  I've had a few problems with mine too but I keep fixing them.  Flooding the circuitry has been the main problem but the button got screwed up on one of them and I figured out how to fix it(which is quite easy) but the button problem is inexcusable and just poor design and/or poor assembly.  At work the other day the vapor on my afternoon stick tapered off then just stopped working completely.  It's a good thing I had my morning stick in the box so I finished the day off with that.  Got home and took apart my stick and squirted it down with alcohol, let it dry off and now it's working fine again.  The leaking problem wouldn't happen if Janty took the small effort to design the 801 atomizer properly.  A vent hole on the side of the atomizer(just like the 901 atomizer) and plug the three holes at the bottom would prevent any juice from leaking into the circuitry no matter how flooded the atomizer gets.  Mostly stupid stuff is causing the problems with the Janty stick and it's ashamed.

[Crossbow]

The first one suffered total switch failure (it fell off)
The second suffered some kind of electrical fault (the magic smoke escaped)
The third has basically drowned. It was pretty clear it wasn't going to last long once juice started leaking out of the switch and usb port everytime I put a fresh cart in. It still kinda works - but not well enough to be more than annoying

[Larry]

It's rediculous that those things are happening with the janty stick when most problems could be avoided if they put a tube about half the length of the atomizer and sealed it at the bottom near the connector.  Then, no matter how much the atomizer leaked, it wouldn't get into the rest of the stick.  Cheap!  I'm sure we're not the only ones having these problems but I guess Janty thinks it's cheaper to replace defective sticks than to spend an extra dollar or two to fix the problem.

[moog]

I did hear a distant rumour that there might be a V3......

[Larry]

They have a few things in the works right now but I haven't heard anything about the stick yet.  Just a small sealed fitting on the end of the atomizer would solve the leaking problem.  No need for another version unless they want to make it into a flash drive or mp3 player.  Right now they have the Cameo, Baby J, Ego, twin box and Telsa filter and all are just prototypes right now.

[moog]

I think the Cameo is on the back burner......the other prototypes just don't appeal...The JS was something that was really quite popular and to make it more sturdy and leak proof would be a winner.....

[Larry]

I'd like it leak proof as well but that's a design flaw they should have addressed in the beginning. 

[Crossbow]

The only good news is that they can be picked up much cheaper now, but even so, at a stick every 2 months, I don't think I'll bother

[Larry]

If you're handy you could always rip out the electronics and turn your stick into a no frills box mod.  That's what I plan on doing if mine ever dies.

[exogenesis]

Not sure how I missed this thread the first time round Crossbow,
but this is certainly a great help in understanding Li batteries.

Helps a lot , thanks

[Syanidi]

great information.

Thanks,

[TheNige]

Great information indeed....but a bit lost on me. 

Perhaps some kind soul could briefly explain the do's and don'ts of unprotected batteries is simple terms for us simple people.
Lets say I had 2x UltraFire (yikes!) TR15270  600mAh 3.0v batteries to charge a 6v device....(lets call it a copper.)

How long are they safe in the charger?
"The atomiser will die off way before the batteries reach a dangerous state of low charge"...but if these batteries were then removed,set aside and forgotten about,would they evenually lose charge to the point of becomeing unstable?

Yeah....Do's and dont's...
What should I do?....and what shouldn't I do?
I can't see them being exceptionaly dangerous or they wouldn't be on the market.Would they?

Cheers
Nige.

[Phil A.]

IIRC, the main thing about unprotected batteries is don't charge them in a charger that's got no "intelligence" in it to prevent overcharging as there's a risk of them blowing up if you overcharge. Also, if you short-circuit one without short circuit protection, it can catch fire or explode. Unprotected batteries are designed to be used in a device that has protection in it (which is why there's none in the battery)
There's actually a picture on this forum somewhere of someone's Janty Stick which did get very badly damaged (to the point of being unrecognisable) so whilst unprotected batteries aren't super dangerous, you do need to be aware that bad things can (and occasionally do!) happen with lithium ion batteries...

[TheNige]

Thanks Phil....That helps a bit.Dont over charge and dont short-circuit.
I'll need to check out if my supplied charger is "intelligent" but even so I can keep a check on that.

What about completly draining them?Anyone?

[exogenesis]

Isn't that what crossbow meant about 'protected' batteries being all about,
i.e. they cut out below 3.x volts, stopping them draining completely & irreversibly chemically changing.

[Crossbow]

Having 'discharged' batteries lying around for long periods of time (multiple weeks) could be an issue, potentially, although the self discharge rate is pretty low. They shouldn't become unstable - more likely just unusable.

As for leaving them in the charger - in theory, as long as either the charger or battery is protected against overcharging, it shouldn't be a problem, but it's certainly good practise to remove them after they are charged. It's not worth worrying about too much though - I tend to charge batteries over night, and so far have had no failures of any sort.

[TheNige]

Thats cool....Thanks Crossbow......Maybe I'll get some sleep tonight. 

[AlanShaw]

Hi all, do the 280 ma batteries that are on the TW site at £12.99 produce more vapour as well as lasting longer??

[Crossbow]

The larger capacity means they will be ever so slightly better, but the main thing is just that they will last longer

[smurf]

Hi all,

This discussion is very interesting. My question is this: Do the lithium batteries have memory? What I have heard is some rechargeables have memory and that if you say for instance, have all you ecig batts dead, can you do like a half hour charge just to get your vape fix? Will this be a problem? 

[NandyDC]

Somewhere I had read that there is no memory problem with the lithium...

[capt12b]

I agree with nandy, if they had a memory the pcc would not be good for the batts at all  

[smurf]

Thanks guy's. That has been constantly on my mind since I got my first starter kit. I was afraid that if I kept taking them out of the charger as soon as the light went green they might end up with a shorter usage time between charges. The manual says charge for eight hours the first time. Then it says the batt is ready when the light goes green. Sometimes my batts only charge for an hour at the most, then the light is green. I just want to get the most usage as possible from the batt. But don't we all? 

[Chaotic]

Great thread everyone, lots of good information, keep it flowin.

[ddracer]

Hi all,

This discussion is very interesting. My question is this: Do the lithium batteries have memory? What I have heard is some rechargeables have memory and that if you say for instance, have all you ecig batts dead, can you do like a half hour charge just to get your vape fix? Will this be a problem? 

Not as such memory effect was only really a problem on Ni-Cad's what would happen is the battery would run for so long then suddenly drop off. It was caused by part charging. The best way to avoid it happening was to run them flat before recharging. Lithium battries do degrade with use but this mainly happens in high C draw applications, eg. running ESC's for high speed motors etc.

Hope this helps.

[Tammy5332]

Love the info

[Geth]

I have a KR808d-1 style e-nic I use for backup. I have 3 of those batteries and 2 PCC's for them. Nice small battery but it doesn't take much time to deplete the battery. I use if for short trips out of the house or when I am doing a lot of physical activity in case it falls out of my pocket like when I'm roughousing with my young sons so I don't lose my favorite tornado tank. I can get a tornado tank battery to last me from waking till I go to sleep. The one reason I keep them around is these particular batteries have a full LIFETIME garantee. If a battery dies I just call the company, get an RMA number and then post it back to them and a free replacement is on it's way. I've had battery issues with then before and they sent me replacements and a SASE bubble mailer for my dead battery before I even shipped out the dead battery. It's a decent company BUT they ONLY sell the KR808D-1 style e-nic, no bottled juice , thread adapters, etc. I don't buy their products anymore but keep them around and refill the cartomizers with TW e-liquid. My only source for my e-cig hardware and supplies is TW for the past few months and I don't see any other suppliers with the discounts and specials , like the yo-yo promo and the weekly discounted items. Add to that the new lower price structure for atomizers, batteries, etc and I don't have any reason to go elsewhere for my supplies.

[b.dave911]

nice work

[Void]

Simple Guidelines to Prolong Lithium-ion Batteries

Do not discharge Li-ion too low; charge more often.
 
A random or partial charge is fine. Li-ion does not need a full charge.
 
Limit the time the battery resides at 4.20/cell (full charge), especially if warm.
 
Moderate the charge current to between 0.5C and 0.8C for cobalt-based lithium-ion. Avoid ultra-fast charging and discharging.
 
If the charger allows, lower the charge voltage limit to prolong battery life.
 
Keep the battery cool. Move it away from heat-generating environments. Avoid hot cars and windowsills.
 
High heat and full state-of-charge, not cycling, cause short battery life laptops. (I assume this include other devices)

Source: http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

[RichJr]

All correct info thanks for posting it.

[teatime]

I was reading this thread last night and, oddly enough, there was some interesting lithium battery news today! Apparently, the University of Leeds is developing a gel lithium batt!

http://www.bbc.co.uk/news/science-environment-14852073

[Killjoy]

Nifty.  I'll be curious to see what come of this research

[terrier]

better batterioes hopefully

[jeffj4873]

Crossbow,
i'M IMPRESSED. I am a Technician by trade and your knowlege of those batteries is really good. Excellent graphs. I learned a couple of things here.

[CraigwSmith]

Great info on this thread.. I suppose by now everyones heard about the guy with the exploding e-cig battery in Florida or Alabama or something? What would cause something like that? I apologize if theres another thread about it but I didn't see one.

[Lettie22]

Great info on this thread.. I suppose by now everyones heard about the guy with the exploding e-cig battery in Florida or Alabama or something? What would cause something like that? I apologize if theres another thread about it but I didn't see one.

Yeah, a 3-page thread so far!

http://www.totallywicked-eliquid.com/forum/general-e-smoking-discussions/well-this-is-not-good-news/

[jediknight129]

can I ask a question about lipos in a different context since people can explain them here?