Let's Talk Batteries

[Laszlo]

*Edit by Rhapsodies Fire*
As per several requests...
And knowing that it is important to keep the discussion going about battery safety I am opening up a new thread for a continuous chat about batteries. Post your theories, experiments and questions....teach & learn. I will be bringing an ongoing battery discussion into this thread from another thread....and possibly others. This is simply an attempt to separate information so it is more easily found for those who may or may not be looking for it.

Here are links to tons and tons of battery information. If you feel there are more links that I need to add...just shoot me a pm with the link and I'll add it.

http://www.e-cigarette-forum.com/forum/ecf-library/129569-rechargeable-batteries.html (there are more useful links at the bottom of this page)

http://www.e-cigarette-forum.com/forum/announcements-rules/77710-basic-safety-specification-mods.html

[URL="http://www.e-cigarette-forum.com/forum/announcements-rules/129007-warning-rechargeable-batteries-mods.html"]http://www.e-cigarette-forum.com/forum/announcements-rules/129007-warning-rechargeable-batteries-mods.html

[URL="http://www.e-cigarette-forum.com/forum/announcements-rules/76078-exploding-mods-current-situation.html"]http://www.e-cigarette-forum.com/forum/announcements-rules/76078-exploding-mods-current-situation.html

[URL]http://www.e-cigarette-forum.com/forum/announcements-rules/269461-exploding-mods-update-february-2012-a.html[/URL][/URL][/URL]

UNSURE's LAW: Cover your bases and have all things in house before the REO arrives!

Btw I noticed its the stacked battery nearest the positive connector that drains first/most.

I'm not doubting your observation, but there's no rational explanation for such a behavior providing the batteries were charged to the same voltage. The current drawn thru both batteries connected in series is exactly the same. If batteries were connected in parallel, it could happen that one battery will drain sooner than the other.

You may possibly have one battery that was used more often or is older and that battery happens to be placed at the top of the stack.

 

[unsure]

I'm not doubting your observation, but there's no rational explanation for such a behavior providing the batteries were charged to the same voltage. The current drawn thru both batteries connected in series is exactly the same. If batteries were connected in parallel, it could happen that one battery will drain sooner than the other.

You may possibly have one battery that was used more often or is older and that battery happens to be placed at the top of the stack.

I don't know the technical reason for it and it is possible that one battery is older than the other (can't confirm since they were given to me) but others have said the same thing in previous posts so if there is a technical reason I'll leave it to the others for an explanation.

 

[beezer]

You know me. I wanna know too. Ya know

 

[davelog]

Maybe the resistance of the battery is different than that of the wiring, meaning the charge from the bottom battery is somehow bottlenecked at the top battery, causing it to drain at a slower rate?

I dunno beans about electricity, just guessing here.

 

[pmoraldo]

I'm not doubting your observation, but there's no rational explanation for such a behavior providing the batteries were charged to the same voltage. The current drawn thru both batteries connected in series is exactly the same. If batteries were connected in parallel, it could happen that one battery will drain sooner than the other.

You may possibly have one battery that was used more often or is older and that battery happens to be placed at the top of the stack.

Not sure about why but I can tell you from experience with stacking IFR14250's one is always drained more than the other

 

[FeistyAlice]

I don't know the technical reason for it and it is possible that one battery is older than the other (can't confirm since they were given to me) but others have said the same thing in previous posts so if there is a technical reason I'll leave it to the others for an explanation.

Just jumping in really quickly and having a little more brain function today. There is a technical reason, described in detail, that I've read, a few times, and understood (I have a strong Physics background, in a "life" long, long ago.). That being the battery closest to the positive contact, in a stacked set, will drain faster than the one in contact with the negative terminal. The set I took out of BP, last night, exhibited the behavior, that I expected, with battery touching positive terminal of mod, having half the voltage left, of that of the battery touching the negative terminal of mod. I'm now writing down the voltages of each battery when they come out of the mod. (It was especially confusing to me, past few days, with my severely diminished "flu brain", with some of the battery sets exhibiting behavior different from what I expected. I'll be recording results for those sets, too, to get to the bottom of my confusion.)

Feisty Alice

{edit} When I get the time, if someone hasn't already done so, I'll post link(s) to the explanation.

 

[unsure]

I'm not doubting your observation, but there's no rational explanation for such a behavior providing the batteries were charged to the same voltage. The current drawn thru both batteries connected in series is exactly the same. If batteries were connected in parallel, it could happen that one battery will drain sooner than the other.

You may possibly have one battery that was used more often or is older and that battery happens to be placed at the top of the stack.

Im curious if you are going by theory or have you actually tested it? I doubled check last night and yes in fact the one battery discharged more than the other and this time I use new fresh off the charger batts.

 

[tmcase]

Not sure about why but I can tell you from experience with stacking IFR14250's one is always drained more than the other

I think this is true of stacking any batteries. It's happened with all of mine.

 

[tmcase]

Im curious if you are going by theory or have you actually tested it? I doubled check last night and yes in fact the one battery discharged more than the other and this time I use new fresh off the charger batts.

I've check my stacked batteries and it's always the one under the carto connection that drains first.

 

[mwa102464]

westamyx,

The top batt always drops off voltage first, this is why it is good to rotate them and mark them A-1, A-2 and so on with your Batts, I use a permanent sharpy to do mine. Your also going to get a little voltage drop once you test it under load with an Atty one it. As for using a IMR Batt and AW Batts, the 18350 IMR will give you a longer run time then the smaller black 16340 IC AW Batt. Buzz's Powerizer Batts will probably give you the longest overall run time though I have not tested them vs the 18350 but I'm sticking with using the IMR 18350 myself

 

[sashwa]

mwa, I have a question for you if I may.

I remember reading that you said you should let your batts rest before you recharge them. Could you explain why and how long they need to rest for? I've not heard that before.

 

[mwa102464]

Sure Sashwa,

It is good to give your Batts a rest in between use & charging cycles, simply it is not good to keep running your batts, by this I mean using them in your Mod then slamming them right on the charger then right back into your mod, this is like continuous use and not good for them or there lifespan. It is best to rest your Batts then when the power cell is depleted and ready for a charge state to set them next to the charger for a while and rest them, then after a rest charge them, then rest them again before use. this is also why people should have multiple pairs of Batts and not just run one or two pairs of Batts, I suggest 4 pair at a minimum for a mod you are using all the time on a daily basis, though I have at least 6 pair myself, I also feel this is of a good safety practice.

 

[FeistyAlice]

mwa, I have a question for you if I may.

I remember reading that you said you should let your batts rest before you recharge them. Could you explain why and how long they need to rest for? I've not heard that before.

I'll answer that one. As usually seen, many times by temperature of the batter, heat, with many batteries and cells, the molecules, in the cells, remain in "motion" for a bit of time right after a charge or discharge. In the case of many batteries you can readily feel the heat of the battery or cell. When I'm running my cleaning 'bots, and have to use the batteries for several cycles, in a day, I'll let them cool off before putting on chargers and if I have to use them quickly, after charging, I throw them in the fridge for a few minutes. I was advised about this many years ago, from the battery experts, on some robot forums. This goes for NiMH and Li-ion packs.

Using 'bots that have battery packs that aren't easy removed and/or that are not placed, out of 'bot, onto an external charger, the heat is not as easy to detect. So you just make it a habit to "rest" them after charging, unless they have been on a "trickle" and, for sure, immediately after a discharge.

It is not always as easy to detect the "heat" in a small cell. The heat, in very simple terms, is caused by molecular movement.

Feisty Alice

 

[sashwa]

I rotate my batts as I use them so they are never used right after they come off the charger. But I didn't know I should let them rest before recharging them.

I've started changing out my batts at night before I go to bed so they can rest while I sleep and then charge them when I get up since I read that. I use to change them out when I got up and then start the recharging up right away.

Thanks for both your replies.

 

[stravaigin]

Sure Sashwa,

It is good to give your Batts a rest in between use & charging cycles, simply it is not good to keep running your batts, by this I mean using them in your Mod then slamming them right on the charger then right back into your mod, this is like continuous use and not good for them or there lifespan. It is best to rest your Batts then when the power cell is depleted and ready for a charge state to set them next to the charger for a while and rest them, then after a rest charge them, then rest them again before use. this is also why people should have multiple pairs of Batts and not just run one or two pairs of Batts, I suggest 4 pair at a minimum for a mod you are using all the time on a daily basis, though I have at least 6 pair myself, I also feel this is of a good safety practice.

Hi Matthew I had no idea about this, so thank you. Roughly, how long would you suggest I let them rest for?

 

[ltrainer]

When I stack batteries the one on the neg side usually reads zero volts so rearranging them won't work. You can rearrange them half way through their useful cycle to prolong the battery life until they reach cutoff.

I've check my stacked batteries and it's always the one under the carto connection that drains first.

I'm really confused by these two replies. Are they contradictory or is it me. Help!

 

[ufo]

Last night, when the voltage control chip cut off, on my BP, and I pulled the two 3 volt batteries out, note 3 volt and not 3.7 volt batteries, New Unused Tenergy LiFEP04 3v, the battery touching the positive terminal of mod, which is the top battery on the Buzz Pro and VV REO, read 2.50 v and the bottom one (touching negative terminal of mod) read 3.15 v. Remember that the voltage "rating" of a cell (battery as we mistakenly call them) is an approximate. The Tenergy 3v LiFEP04 batteries come off the charger a little above 3.2v. It looks like the bottom battery was hardly depleted. Interesting.

It is normal.
All PV (and I say all) tend to to download the Batts in non-uniform manner.
As has been stated by others, the best way is to invert them during the vaping.
Your Tenergy freshly charged come off only with 3.2 v??
Very strange. I've had 10 pairs of tenergy lifepo4 (4 are indeed of almost 2 years old), but freshly charged, they come to about 3,9-4v, and after one day, if I let them rest, arriving at about 3.6- 3.7 v, but I never I get only 3.2v with Tenergy at full charge
I, for my Tenergy, use exclusively the Tenergy charger appropriate for Lifepo4. You? what charger you have for your lifepo4? because the lower charging may depend on the type of charger used.

More testing to come. Right now I have two AW LiFEPO4 3v batteries in the BP set at 5.1v. (The Resurector carto, constantly flooded, in a tank, is now a week in use. I may need the higher voltage, for satisfaction, because of my throat healing and/or the carto is getting gunked and just needs more voltage to give satisfaction. It is probably a bit of both.)

I know the AW Lifepo4 3v: I have some of them. They have, despite their 500mAh, more or less the same performance and durability of Tenergy: although, personally, I prefer the Tenergy LiFePO4. I think that charging them is slightly more durable (although their 750mAh are only nominal, while the 500mah of AW are real ). However, the two are very similar, but the Tenergy give me more reliance. Years ago, just came out on the market, for the first time, the lithium polymer cells, I bought some of them, and they are still going well (after 2 years) like new

and it is yet to be determined which 18xxx battery will give the longest performance or life of the battery, re. charge/discharge cycles.

Feisty Alice

{edit} yet to be reported, here, as to which battery will provide......

My personal opinion: AW IMR 18350.

I've tried several: IMR no brand, UF 18350 1200mAh xls, etc ...., but the AW IMR between the category of 18xxx category, are the best, for me

 

[ufo]

I suggest 4 pair at a minimum for a mod you are using all the time on a daily basis, though I have at least 6 pair myself, I also feel this is of a good safety practice.

I agree.

4 are few and the risk is damaging them with too intense use due to the small frequency of rotation. Better 6, or even 8 so as to alternate them.
Then, for heavy vaper (like me), better 10 Batts. For ex, I use 2-3 pairs daily and the remaining are always in recharging. I'm talking, of course, of the Tenergy Lifepo4 3v (and in general of batts size 16340/CR123A)

With respect to the AW IMR 18350 (given the increased amperage), I would say that 6 is more than enough to power a single PV, even in case of heavy vaping

 

[FeistyAlice]

It is normal.
All PV (and I say all) tend to to download the Batts in non-uniform manner.
As has been stated by others, the best way is to invert them during the vaping.
Your Tenergy freshly charged come off only with 3.2 v??
Very strange. I've had 10 pairs of tenergy lifepo4 (4 are indeed of almost 2 years old), but freshly charged, they come to about 3,9-4v, and after one day, if I let them rest, arriving at about 3.6- 3.7 v, but I never I get only 3.2v with Tenergy at full charge
I, for my Tenergy, use exclusively the Tenergy charger appropriate for Lifepo4. You? what charger you have for your lifepo4? because the lower charging may depend on the type of charger used.

I just checked all my 3v LiFEP04 batteries; those that just came off charger, those that came off charger an hour or so ago, and those that have been charged and stored for 24-48 hours.

History of these batteries. They have been used very sparingly since purchase. Some were purchased Feb/March 2011 and two sets of the Tenergy Green were purchased with the standard 3.2v Tenergy charger, sold as a set with charger and two batteries, Green Label. Two chargers, with two batteries, each charger were purchased Summer 2011. Before purchaseing the dedicated Tenergy chargers I used a Universal charger that charges NiCad, NMHD, and Lithium chemistries, from 1.7v up to 9v. It has independent channels and has a chip that detects chemistry (so they say) and voltage limit of batteries. I've used the Uni charger for about five years, with all types of battery chemistries, and I've never had any issues with uneven charging, when two were charged at same time, nor with overcharging. I do, though, only charge same type/capacity batteries, at the same time. In Summer 2011, I started using the Tenergy 3.2v charger for all 3v batteries.

The early sets had maybe 10 charge/use cycles and the Summer Tenergy sets had probably only 2-3 charge use cycles.

Since Fall 2011 they have been stored, without topping up, but charged before storing. I just pulled them out a week ago and charged them up, first time on the WF-188, set at 3v and low amp settings. Then I retrieved one of my Tenergy chargers, from "storage," and have been using it since.

I did not use the batteries, fresh out of storage, rather I charged them first. But I did check the voltage on them, fresh out of storage, and all were at or slightly above or slightly below 3v.

The batteries are pictured below. All are LiFEP04. The Green Label Tenergy are labeled 3.2v while the Blue Label Tenergy are labeled 3.0v. Neither the Green nor the Blue have any marking that indicates mAH rating. The Blue AW are labeled with mAH, at 500 mAH but do not have any marking indicating voltage. All very interesting!!

Fresh Battery Readings.

Green Label Tenergy: 3.37-3.56
Blue Label Tenergy: 3.10-3.23
AW: 3.45 to 3.55

I'm not sure why we have a difference, Ufo, unless my batteries have been affected by long storage and or lack of recent use. The multimeter is a very inexpensive digital. I have two of the same kind and get virtually identical readings from both MMs. They have always give me what should be expected from fresh 3.7v and 4.8v batteries. I have other short batteries, 3.7v, Li-ion protected, UltrFire and AW, and one set of unprotected Powerizers I purchased with the Buzz Pro.

What voltage readings are others getting after pulling off charger and, also, after batteries have rested a bit?

The discussed LiFEP04 batteries are pictured below along with one of the Tenergy 3.2v chargers. BTW.... I'm charging using a 110v input to charger power brick.

 

[FeistyAlice]

Thanks again MXBNW, Wayne, for the suggestion to change position of batteries, several times, during one use cycle. Most EXCELLENT Tip!!!!! I started doing that right after I read your post. As I'm using the BP only when sitting down, in recliner, with a heavy drinking glass to set it in (don't need to do that with REOs), and not carrying it around, as I do things around and about, the BP is not getting used as much as it would be if I were carrying it around...... that's the job of REOs. And, I'm switching out the battery positions about every hour of use. So far the batteries are coming out of BP, when the chip shuts power off, due to low battery voltage, both batteries coming out virtually the same voltage. YEAH!!!!! This is the easiest way to maintain health of stacked batteries that I have found!!!!!!!!!!

Feisty Alice