Why Such Minimal Information on Which (Lithium) Batteries to Use?

Batteries and Chargers Rechargeable Batteries
1

I looked at all the Sticky topics and don’t see this topic specifically addressed, though it is touched on in randomly throughout the Forum.

Many popular lights use 18650s. When choosing batteries, we have to choose protected vs unprotected, and flat top vs button top, resulting in 4 possible combinations. In some lights, any of the 4 possible combinations will apparently work. But others have specific requirements.

First up is size. All things being equal, protected cells are longer than unprotected, and button top are longer than flat top. Some lights will not accept the (longest) protected cells, but rarely do I see a maximum cell length in a flashlight ad. Sometimes an ad will state that a light will accept protected cells, but do they mean ALL brands, and both flat and button top?

Wouldn’t it be expected that the sellers or manufacturers of lights would state the maximum cell length a given light would accept? It seems silly that every potential buyer should have to contact them to ask this question, or poke around the flashlight forums looking for some user to have posted the information. Especially since cells are not all the same size (“Will your Groovyfire XY light will take my AW 2200s (66.4mm)? What about my Tenergy 2600s (66.7 mm)? What about my Orbtronic 3400s (68.9mm)?” etc.

Second is protected vs unprotected. It would help if ads stated whether protected (or unprotected!) cells are required or recommended for some reason. For example, I read an opinion that because Fenix sells only protected cells, their lights are intended to be used only with protected cells, but their ads do not specifically state this.

Finally, flat top vs button top. I have read random posts over the years about lights that work with flat tops but not button tops and vice versa (leaving aside magnets and solder blobs). Again, this information does not seem to be readily available in ads.

My point is just that, with no standardization, it seems to be much harder than necessary to know for sure which cells one will need to power a given light. If I see an 18650 light I would like, I feel like I have to go digging to figure out WHICH 18650 it needs, or I have to have an assortment of all 4 combinations on hand just in case.

Bottom line: If I want to buy a Convoy S2 or somebody’s C8, or whatever, it would help to simply know the maximum cell length it will accept, and whether there is a need to use protected cells. Am I overstating?

2

Simply put, if you purchase a normal light and it doesn’t work with an 18650 which is protected and has a button top, someone has screwed up. At least that’s my opinion. Certain specialty lights and bad production runs might require flat top, short cells, etc. Some lights have very tight tubes and do not accept the wider cells. Again, this applies to either specialty lights (which will often specify this information!) or bad production runs. Dealing with bad production runs is just part of cheap flashlights.

3

There’s been more than a few instances reported where a seller said a particular cell was compatible but wasn’t. Best to always remember that they just want you to buy their products and that most of them have no means of actually checking this. Most simply repeat what their manufacturer tells them. And there have been production changes found with several lights which the seller never noted that changes which cells work.

The best you can do us search for specifics on light forums and ask if they’re old or not to be found. Better to trust us than them.

Phil

4

You’re going about it all wrong, see, what you do is you buy about 300 assorted cells for your 100 flashlights, then when you get a new light, you play around with all those cells and figure out which one’s your new light likes best and you order a few more of those. Simple! :slight_smile:

OR, you buy all one kind, a good one, like an Efest Purple 35A flat top, and then you make whatever modification is necessary to adapt a light to work with that cell.

When you buy a car, does anyone tell you what tires to put on it? You know a size, but which one of about 400 choices is the best one for that car? This is life and death stuff, how do you really know? A Firestone 721 might allow a break in traction when it’s wet out, while a Goodyear Aquatread will work splendidly in the rain but might let you down when it snows. How do you know what to buy? Research, make an educated decision, and carry on. Just like with the lights and cells. You have to do your homework.

5

I like your analogy DB.

6

I’m having trouble feeling the analogy.
In the tyres case, the consumer knows which size tyre to put on.
The variable being the performance of said tyre.
I’m the cells case, the consumer has to find out themselves which size to use.
If the consumer had no reference as to which size tyre to put on, the analogy would fit.

7

I appreciate the feedback and especially nobody taking me to task for being a relative noob.

Wight, you are saying what I am thinking. A 18650 light ought to fit a 18650 cell, unless it is a real specialty light (like tiniest possible) or a real specialty cell (like a 18650 that is really a 18700). Unfortunately, when a cell doesn’t fit, I think the buyer is sort of stuck sorting out a cell that will fit rather than returning the light as “defective,” especially if ordered from one of our friends in China.

SawMaster, I don’t post much but I do try to read the forums a lot, which is where some of my a) information and b) frustration comes from. I don’t want to have to search for “maximum cell size” for every light I am looking at but at least if I have to, I have a place to turn.

DB Custom, LOL I knew that was coming. Of course, I need to have 300 assorted cells, what was I thinking? Though I am a lightweight compared to many here, I already have way more lights that anyone could “need” and enough CR123s and AAs to last a decade in the lights I usually use. Getting interested in 18650 lights, I’d rather not have to buy 30 or 40 in a dozen different configurations just to be safe.

As far as tires, to me it is more like buying a car that takes one of the most popular tire sizes—like 205/55R16—and finding out that the Firestone 721 will fit but the Goodyear Aquatread in the same size will not.

Maybe I will settle on a small-ish cell and hope whatever light(s) I choose will fit. I will look into those Efests.

8

Some manufacturers like Zebralight mentioned in their publications that their latest SC600 mk3 will only accept 65mm length 18650, making protected button-top battery incompatible with their newer lights,
while some manufacturers like Nitecore normally specify that their lights can only accept button-top 18650, so like what DB said, we have to do our homework.

9

Good on Zebralight for providing that information!

Unfortunately, I don’t see anything about max cell size or type (protected/unprotected; flat top/button top) on Nitecore’s website.

Or ThruNite.
Or Ultrafire
Or Olight.
Or SolarForce.
Or Imalent.
Or Manker.
Or Brinyte.
Or TrustFire.
Or JetBeam.
Or Nextorch.
Or Fenix.
Or ThorFire.
Or Niwalker.

I got tired of looking. Many brands do not seem to have a manufacturer’s website: SkyRay, DQG, Astrolux, Eagle Eye, Convoy, etc.

10

Is that because those brands are literally only that ? A name stamped on to generic torches made en masse in one large Chinese factory ?

11

Certainly, as in anything else, such as tablets, electronics components, clothing, shoes, cell phones, computer monitors, so on and so forth, there are a few factories which manufacture to customer specification. So, they manufacture and place whatever name the customer wants on them. Always been that way.

Some lights will not take protected button top cells, but the vast majority will. Do you need protected cells? By asking that question, I would say yes you do. People not well versed with Li-ion cells should use protected cells. Unprotected cells could result in problems with direct shorts causing catastrophic cell failure, where protected cells "should" to stop direct shorts, by opening the circuit and thereby stopping the flow of current in the cell. Is it up to the flashlight manufacturer or seller to tell you that? I do not think so. I think since most lights are sold without cells, there is no way a seller or mfg. can tell you which cells to use, since there are so many possible combination of cells and lights.

12

:smiley: just :smiley:

13

Apart from the safety aspect as mentioned by OL, another reason some lights would benefit from protected cells is if they have no low-voltage cutoff. It may be possible to run a cell down past it's minimum recommended voltage (typically 2.5-2.7V). Usually, by the time the voltage has dropped so far there is little light coming out anyway, but if accidentally left switched on unattended this might be an issue.

High performance hotrods (Dale's specialty) will require unprotected cells as protection circuits would trip under the high-amp loads being drawn.

Yep, the variations in cell length and battery carrier or tube length is annoying. I think most of us probably have a few lights that are incompatible with some of our cells. The most forgiving lights are probably those with both driver and tailcap springs.

14

While not ideal, nor easy for a newcomer to the hobby, it is on us to determine through research or experimentation which size cells are going to fit into a specific light.

Is it right? Probably not… Is it easy? Not always…

But when dealing with flashlight manufacturers, especially budget ones, no amount of internet ranting is going to make them change how they do things. They will always state that the light outputs 4000 lumens from an XML-T6-4D emitter at only 1.04A, and they will rarely state what size or type of lithium ion cells fit the tube.

Also, HereAgainAgain, you’re having trouble with the analogy because you’re talking about something called a “tyre”…. we were talking about tires. The round rubber things that get filled with air and make cars roll. I don’t know what the heck a “tyre” is. :stuck_out_tongue: :bigsmile:

15

The tire analogy fits, you know what SIZE cell to buy, just like the tire. But do you know how it’s going to act on YOUR car? Performance, how do you know how a tire is going to perform? I have tested many brands and sizes, car and motorcycle, many times a specific tire in one size outperforms it’s other size siblings. A Dunlop D65 radial tire in 225/60 16 will severely outperform the same model tire in 185/70 14. So how do you KNOW? You can’t. Great reviews on a GoodYear Aquatread in a 225/60 16 may mean absolutely nothing for your 185/70 14, the same tire, same company, radically different results. You have to research. Dunlop K595 motorcycle tires are raved about. For my size, I found they lost traction downshifting and would slip on corners with a mere 1000 miles on em. On the other hand, the same size Metzler ME-1 would pull wheelies in the rain all the way down to a slick. In much the same way, the Efest Purple IMR35A that I love in so many lights loses out to the LG HE-2 in my Ti X6 Quad Nichia 219C, a rare occurrence but the truth learned by experimenting. (17+A from the Efest cell, 21.1A from the LG)

Your car, like your flashlight, demands a specific size. How you drive (how you use your light) and what extremes you put either through will help you determine what you need for your usage… only research is going to solve this dilemma for you. In other words, you can’t be lazy, you have to do the homework. Fenix will tell you to buy only Fenix brand cells, so will Nitecore, so how does that help you? It doesn’t.

16

I think the tyre analogy is not apt. I used a Keeppower 18650 in my Manker U11 and it crushed the top. How often does using a tyre once damage it? Tyres are marked by width, diameter and speed rating. Batteries are sold by size but they do not conform to the size. The problem is that they were never intended to be used naked. They were made to go inside packs, with lots of protection circuitry. But some people decided to take naked cells, stick on a basic protection circuit, and a thin plasic wrapper. So it’s all a bit Heath Robinson. I wish we could buy properly made cells with protection designed in from the outset.

17

Put a mudder on your car, proper size, watch it tear up your fenders. :stuck_out_tongue:

The true problem is that the cells were indeed manufactured to be assembled into packs, then someone comes along and adds a protection circuit that varies widely in thickness, they may or may not remove the original wrap, possibly doubling thickness and also adding that connection strip. So by making it a protected cell, they changed it’s call size. The manufacturer’s, to my knowledge, do not make a protected cell, and since the protection circuits can vary so widely, there’s very little way to really know what you’re getting WHEN YOU BUY CHEAP CELLS.

18

What is a mudder? What is a fender?

19

Don’t ya’ll off-road over there? Seriously?

A mud tire has very pronounced grip, for digging into deep mud and self-cleaning, throwing mud out of the tread so it can continue to bite. The fender on your car covers the tires, preventing mud and water and debris from being slug out and into other traffic. A mudder can be very oversize, cut into the fenders of the car and cause all kinds of damage. They’re typically made for trucks, pick-ups of 4x4 design primarily.

Yeah, I know, y’all don’t really know what a pick-up truck is. We have them EVERYWHERE!

A Toyota Tacoma 4x4 with mudders

20

Ah, okay, but normal tyres fit, just get the right code. Don’t fit ‘mudders’ to one of these:

Psst: we don’t all drive those little cars. Mine is much much bigger:

As you can see. :slight_smile: