Can YOU help me with battery Safety please!?

Batteries and Chargers Rechargeable Batteries
1

Hello, this is my first post at BLF - and its a shameless attempt to siphon information from the longtime members. So for that, and there sheer length of the post, I apologize in advance.

2 weeks ago I knew nothing about Cree LED's and 18650 Batteries and whatnot. All I wanted was a Tactical Flashlight for Home protection (blinding upper hand factor) And I was thrust into a world of maddness that I never knew existed (the underground highpowered flashlight world).

I did about 2 days of research and bought a WF-501B w/T6 Drop in, It came with two 18650 Ultrafire's and cheapo Charger. Probably a regular "first buy" for many.

Then, I wanted something that throws further.. Why? Im not sure.. I just do. I've become addicted to high power compact flashlight's and I'm not quite sure why. I now understand this Forum doubles as a support group. Anyhow..

Did some more research and figured I needed an HS 801 with an R2 Cree. So I Bought This Lengthened (2 x 18650's) UniqueFire HS-801 for $23.00 Shipped.

AFTER I buy it, I read horror stories of Double cell Lights Blowing up like small WMD's in their unsuspecting owners hands, Like nuclear budget hand Grenades. Then I read more.. What? 18650's have to be watched on the charger like a sleeping Newborn, In order to prevent my house being napalmed from the inside from a bursting 18650 cell. I've spent 4 days reading about batteries and the horror stories of...

These are very "newb" questions, and I've done alot of research. I'm asking alot, But you BLF folks seem to be a pretty nice lot, so I have three questions that, despite how much research I do, I cannot find a definitive answer:

1. What is the MOST safe charger in YOUR opinion? (I forget to take the trash out 9 times out of 10, no less remember to take a battery off a charger before it turns into a mazel-Tov battery bomb.) I Currently own a Maha C808M Charger for all my NiMH batteries and I can leave batteries i that thing for a week if I want. I'm looking for something that will SHUT OFF when the batteries are charged. And is hassle free, I really don't want a "hobby" charger that I see mentioned here, because it looks too difficult with all the wires and clamps and complexity.

2. What are the dangers of Double Battery Lights? And how can I prevent blow ups? Should I just stick to AA or AAA lights since I'm having to ask all these questions?

3. In Your Opinion, what is the Best 18650 Battery there is? As far as safety, reliability cost reputation, etc. I have read so many charts and graphs, and they all seem to be good, but nobody has ever said "these seem to be the overall best batteries"

I have kids, I cant risk maiming them with molten battery Lithium! My whole reason for the light is protection. And as I do understand there are no "absolute safe, fool proof ; never fail" chargers out there.. However - Would still like your input if you have the time to answer my thread (especially after having taken the time to read the whole thing)

Thanks again in advance! I'll be watching this thread closely. If I have missed Threads on this forum that have the answers I'm looking for, don't hesitate to give me a snarl and shoot me the link.

2

Hah, I understand your fears completely. I was the same way a few months ago!

1. There are a lot of good chargers out there. What I use now is a Xtar Wp2 II, it gets great reviews and a lot of people here have it :) Bought mine from this seller, on this site. He's based in USA and it arrived in like 3 days after i paid.

2. If you use good brand/trusted batteries that are the same charge state (don't use one dead with one full charged) then it will be fine. Don't overcharge or under discharge, use a multimeter to test the batteries every so often. Use protected batteries, these have a circuit built in that will not let the battery over charge or under discharge (but i still test mine with a multimeter to be sure) I would avoid using the cheap batteries that came with your light.

3. there are many many great 18650's out there...but also many many terrible ones. Don't buy cheap ones. Look for reviews on here before buying, and again, i recommend protected ones. Right now I have Trustfire Flames and Tenergy batteries and both work well for me.

3

Hi, and welcome to BLF!

Some answers below. I bet others will give you even more info soon.

1. I'm very happy with my XTAR WP2 II. It always stops at 4.16V, like a clockwork.

..but I'm always extra careful during the first few times I use a new charger. Anything can be wrong, no matter in what country the charger is made in.

2. The main danger is to use unmatched cells: Other battery starts violently charging another and there you go..

To prevent this, you should:
- take one pair of new batteries and keep them always together in the same light
- measure the batteries before and after using them in multi-cell light (and if the voltages differ -> get another pair - my own limit for this is 0.02V - playing safe I guess..)

3. There's no such thing as a best cell, but Panasonic & Sanyo cells are considered to be good. Add well known protection circuit and good wrapping and you'll be both happy and safe.

I have been using XTAR 2600mAh 18700s, which are based on Sanyo cells.

Hope this helps.

4

I have the same fears as you.

I flat out don't buy torches that require more than one 18650 battery. I don't watch my charge voltages/cell matching like others here, and I don't want to put that much work into inserting batteries to get light.

So I just don't go there.

5

Some good questions. I'll try to answer what I can.

Xtar WP2 II charger is a good one. You can buy it from Serena in a thread here for around $18. Trustfire TR003P4 is another good one. The Xtar's had some problems but I think they have that fixed with the built-in circuitry I think it was. I have 3 Xtar chargers and they are good. And they are supposed to be very safe.

They say double batteries are more dangerous since you are stacking usually in parallel on top of each other. More to go wrong I suppose. But if you buy a good multimeter like the red Innova 3320 from Walamrt for $25 you can check the voltage on each cell after charging to make sure that it is safe to use. Should be somewhere between 4.12 and 4.23 volts depending on your charger or at least the ones I own. You don't want a charger that will go much higher than that for a top end. 4.30 is said to be very dangerous for when the battery vents I was told. Could explode. Lithion Ion batteries are good batteries and very good technology I think. That's why they went to it. They can be charged over and over and have no memory effect so you can charge them at any state. I don't think they are meant to go below 2.75 volts. But you will have to talk to others for sure on that one. But I think the ones that are protected(PCB) protection circuit board will kick in to prevent any mishaps.

For the money the best 18650 batteries are probably the Hi-Max off of ebay. Xtar 18700 are good too. You can buy them from Serena here on this site if you look for $13.50, and the hi-Max are about $13 a pair from a guy off of ebay. The Trustfire Flames from Manafont are good ones too. If I had to pick I would go with the Hi-Max for best capacity.

If you need the link for the ebay seller I can get if for you.

Brad

6

And I meant to type Walmart on the Innova 3320 multimeter. Buy it if you don't have a good multimeter. I can help you if you want to check barttery voltage if you don't know how.

7

I trust XTAR WP2 II more than Trustfire TR003P4. For some reason my TR003P4 terminates quite randomly at 4.16..4.24V, but XTAR is always 4.16V, sharp!

Don't get me wrong: TR003P4 is ok, but I think XTAR WP2 II is more reliable.

8

Usually a thread about the safest charger turns into a big pissing match. I actually like my Trustfire TR-001 charger I have bought a couple of them and they have been dead reliable. I test all the batteries that come off the charger with a multimeter, I never leave it unattended and I occasionally touch the batteries during charging to make sure they are not getting hot.

I also own a Turnigy Accucell 6 charger I feel this is a very safe charger if you know how to use it and you put the correct settings in it, the chances of a mishap with this unit are quite low.

As long as you use a multimeter and monitor your batteries religiously with it, double battery lights can be relatively safe. Make sure you have a set that takes the same amount of time to charge and discharge. Always check the voltage of the batteries when you take them out of the light and before you put them in the light. The batteries that keep the closest start and end voltage are the safest matched set to use.

The safest batteries are the ones you trust the least because you will keep a better eye on them then the uber expensive ones that can go boom just like the cheapies. I have over 40 Trustfire Flame 18650s that get tons of use and have not had a single mishap yet. I have several multicell lights including A DRY triple X and a Skyay triple X.

Let the games begin.

9

Just so there is no confusion, stacking batteries on top of each other is in series not in parallel. The risk of series configuration is one battery (a good or strong one) attempting to charge the other (the bad or weaker one).

10

Stacking in a normal torch is series but for one to try and charge the other they would have to be in parallel. In series the strong cell will be forcing current through the weak cell when in a complete circuit, nothing will happen open circuit.

11

Well that's what I meant to say. Thanks for correcting me.

12

But wouldn't that mean that cells in parallel are at least as dangerous as those in series? I didn't think that was the case?

13

Hi, Blinder and welcome to the support group. I too am a bit of a noobie and also a budding flashaholic. I'm a cyclist that does night riding, so I started accumulating bike lights several years ago to support that habit. In addition to dedicated bike lights, which usually go on the bars, I also started dabbling in flashlights for use on the helmet. I started off with regular AA, then moved up to rechargeables, but I was never satisfied with the light level. When I got a 700 lumen bar light last year, I discovered that the AA flashlights were washed out by the brighter lights so the next progression in my light addiction was 18650 Lion torches. I now have 4 nice 18650 flashlights, with 2 more on the way, including a 3xT6 XM-L monster that uses 2 stacked batteries - this is not really for the bike, more of a wall flower/wow light. I read about all the same horror stories you referred to so I did some heavy duty research as well and asked a lot of questions here, on CPF, MTBR forums and a few others. Here's what I've found out:

1. I purchased an Xtar WP2 II from the same vendor that 08CivicSi referred to. This after just using cheap $4.95 black box China chargers. It really does get a lot of positive reviews and so does the vendor.

2. I've probably made the same mistake as a lot of other new flashaholics in that I assumed the shiny plastic on batteries and the claimed mAh rating meant it was 'new' and the most powerful. There are plenty of horror stories out there that can debunk that myth - many are repackaged old batteries and the ratings are inflated. With my new 3xT6, I invested in some new Callie's Kustoms that will be used only with this light. Callie's are very expensive, but I think they are worth the piece of mind. Another source for good quality protected cells is Outdoor Store. Both of these batteries use new Panasonic 3100 mAh. I invested in a relatively simple and inexpensive digital multimeter from Radio Shack. A cycling friend is an electrical engineer and while he has an $800+ jobby, he assured me that it is more than adequate for an electronics dunce like me.

4. I'm teaching myself all about electricity and electronics, including how to use this multimeter on flashlights and batteries and actually understand what I am measuring. I started on the internet, but am now working on getting through the Boy Scouts merit badge guide on Electronics. It seems to be a good first step for someone who knows next to nothing about the subject. To ILIKEFLASHLIGHTS: I would love a primer on how to use the MM to check batteries!

Good luck on your quest and your lumen addiction!

14

1)Just use protected batteries from the cheap trustfire flames(take care fakes around) to panasonic/sanyo

2)Using multiple cell be sure that are all of the same type and with the same charge level(look the voltage or to be sure recharge the cell first)

3)Don't discharge litio cells too much and don't store them discharged(continue losing power with the time)

is better charge the litio often don't have memory effect instead of leave them discarged

the best solution is to store cells in health is at 60% of charge ~3,7v(is discharged at 2,7v and full charged at 4,25v) in a cool place

4) buy a charged that don't self explode

I have a cheap trustfire tr001 from 1 year as said the voltage is not constant go from 4,17 to 4,23(protected cells stop the charge at 4,23v usually) but do the job

never recharge cells that goes under 2,5v(edit 1,5v) is dangerous better never go under 2,9v than recharge

15

The general rule is not to recharge cells that are 1.5V for more than a week. But if you protection has been tripped the voltage reading will be 0V.

For different cells, different depletion voltages. Panasonic NCR18650 & NCR1860A are rated to work down to 2.5V.

Sanyo UR18650FM 2600mAh are rated down to 2.75V so that's what you should keep in mind.

However the purpose of a protected battery is to forget about the over-discharge and over-charge issues. The protection will be tripped when these things happen. That's the theory anyway.

16

ya maybe is 1,5v sry XD btw better charge often

Depth of discharge

Discharge cycles

Table 2: Cycle life and depth of discharge

A partial discharge reduces stress and prolongs battery life. Elevated temperature and high currents also affect cycle life.

100% DoD

50% DoD

25% DoD

10% DoD

500

1500

2500

4700

17

That can be also said about the charge termination voltage, at 4.1V you end up with more cycles than at 4.25V

I actually though of tha. I use mostly lower outputs, I ended up with 50 cycles is a year on some cells. In this pace I am far away from the 500 cycles and the cells will degrade naturally in 3 to 5 years. So for that reason I am somehow relaxed with some cells.

Elevated temperatures affect cycle life, but Li-Ion cells perform better at 40 Celsius ambient than at 0 Celsius according to the official discharge graphs of the manufacturers.

18

...and I would still suggest measuring the voltage after charging the cells. Otherwise you might not notice the situation with either one overcharged or one dead cell and this is what might happen then (use Google translate or just check the pictures from post #16)!

19

Well, I certainly appreciate all your advice here people! Ill never use unprotected, and as im starting to read, that the protected batteries are just that, the protection will trigger before the battery blows?

By the way, Does anyone know the actual mechanism that "triggers" in the protected batteries? By that I mean, Is it some kind of resistor that pops at a certain voltage?

Anyone heard of protected batteries blowing?

And, lastly, does anyone know the chemical process that happens to create the explosion? Or is it just a build up of heat that quickly vents causing a small blowup?

thanks for answering everyone, some really good discussion giving me great avenues of further research here!

20

See, seeing that makes me just wanna go single cell light and forget about the extra battery..chances are I probably wont need the light to work for 4 hours straight on high, It would just be nice if it would. That battery didnt look protected though. poor guy almost lost his hands. I just need a flashlight not a pipebomb.