# Flat Topped vs. Button-Topped, what's the deal?



## belomeclone (Apr 5, 2011)

So apparently my EagleTac Flashlights require Button Topped without some, uh, modding. But my question is, why don't people just use Button Topped? What's the appeal of Flat Topped? Is there more capacity in them or something?

On that note....

1. Are there any dangers to high-capacity batteries over the lower ones?

2. What are, uh, the best button topped cells for me? I want high capacity.


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## HooNz (Apr 5, 2011)

belomeclone said:


> What's the appeal of Flat Topped? .





"*Free*" is the operative word!

cheers, Paul


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## arek98 (Apr 5, 2011)

I assume you asking about 18650 batteries. Flat top is usually meant for battery packs. Since a lot of 18650 is used in packs (most laptop batteries is using them) flat top are pretty common. There is no particular difference between flat top and button top (assuming that particular cell is available in both)

1. No. Crappy cells are more dangerous than quality ones regardless of capacity (all Li-Ions need to be handled carefully).
2. Panasonic 2900mAh are as good as it gets for now. They are sold in MP (Redilast 2900mAh button top). 

Some info from LuxLuthor


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## arek98 (Apr 5, 2011)

HooNz said:


> "*Free*" is the operative word!


 
Hmm, I'm not sure. If you have source of good laptop batteries that you may dismantle then right but most people (I'm computer guy and I qualify as one of these most) may either buy new battery and get cells from it - not free, or get cells from old laptop battery - almost dead, end of life cells.


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## HKJ (Apr 5, 2011)

Flat top cells are shorter. The button top is a added to the cell when they are repacked for consumer user.

In my roundup of 18650 I have added information both about length and top.


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## bshanahan14rulz (Apr 5, 2011)

I got 6 free Sanyo 2600mAh cells. flat-top. only 50 charge cycles on 'em. Not all battery packs fail because of being old.


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## belomeclone (Apr 5, 2011)

I had a laptop lying around. So you mean inside its battery pack isn't some chemistry, it's just these lithium batteries? Like the old 9 Volt prank with AAs, but for real?


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## Stephen Wallace (Apr 6, 2011)

If you opened up most 9v PP3 batteries, you would actually find six cells inside, wired in series, but they are much smaller than AA cells - smaller than AAA cells even. I think they are AAAA cells.


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## HooNz (Apr 6, 2011)

arek98 said:


> Hmm, I'm not sure. If you have source of good laptop batteries that you may dismantle then right but most people (I'm computer guy and I qualify as one of these most) may either buy new battery and get cells from it - not free, or get cells from old laptop battery - almost dead, end of life cells.



Well i am very sure , i would not pay 2 bob for used batteries but if they are free and good i'll not complain (much)yet , i have the 8 that i have are less than a year old and belonged to a associates laptop who purchased the pack so , Free for me! and i gave away the lappy .

Any battery used is not worth 2 bob imo and for the prices seen for new 18650 flatop or buttons id'e personally buy the newies , but then again i know what i am doing even if i forget to remove one from my homemade charger that got to 4.5v and is still ok 
Paul

Operative Free .


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## SubLGT (Dec 15, 2014)

*Flat Top and Button Top 18650 Battery*

Am I correct in my understanding that the primary manufacturers (Panasonic, LG, etc) of 18650 cells manufacture _only_ flat top cells? 

And the button top versions of 18650 batteries are created by resellers such as KeepPower, by adding a button to the flat top?


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## HKJ (Dec 15, 2014)

*Re: Flat Top and Button Top 18650 Battery*



SubLGT said:


> Am I correct in my understanding that the primary manufacturers (Panasonic, LG, etc) of 18650 cells manufacture _only_ flat top cells?
> 
> And the button top versions of 18650 batteries are created by resellers such as KeepPower, by adding a button to the flat top?



Correct, only flat top unprotected cells.
But there is some Chinese factories that makes button top cells. AW's 2200mAh cell is native button top and a cheap LiIon cell I disassembled was also native button top:


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## SubLGT (Dec 15, 2014)

*Re: Flat Top and Button Top 18650 Battery*

If a reseller like Efest or KeepPower adds a button top (but no PCB) to a flat top Panasonic 18650 cell, how is the button top attached? With a spot weld?


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## HKJ (Dec 15, 2014)

*Re: Flat Top and Button Top 18650 Battery*



SubLGT said:


> how is the button top attached? With a spot weld?



Some do that, it can be a bit tricky. Most uses a cheaper method:




I.e. a short metal strip is spot welded on both the top and the battery.


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## SubLGT (Dec 15, 2014)

*Re: Flat Top and Button Top 18650 Battery*

Thanks HKJ. The explanation and photos are appreciated.


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## mummel (Jan 15, 2015)

*Button tops vs flat batteries?*

Threads Merged - Norm

I understand the buttons have some sort of protector in them. How risky is it really to use a flat battery? Thanks.


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## thedoc007 (Jan 15, 2015)

*Re: Button tops vs flat batteries?*

There are button tops with protection, and without. There are flat tops with protection, and without. The button, or lack thereof, does not indicate whether a cell is protected. There is no difference in risk between button top and flat top cells, all else equal. The main thing is to make sure the cell fits well and makes good contact - some lights work better with one type or the other.


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## alpg88 (Jan 15, 2015)

*Re: Button tops vs flat batteries?*

the biggest risk you may face is that flat top cell may not make contact in some lights, that is all,


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## Chicken Drumstick (Jan 15, 2015)

*Re: Button tops vs flat batteries?*

Nope. Button top simply describes the shape of the + positive end of the battery.

Flat top is flat and will need a spring or something else sticking out on the driver to make contact. These won't work for running in series well as they also wont make contact with the battery infront.

You get raised tops too, although more comment on larger batteries, 26650's or maybe 18650's. These might be called button sometimes. But they have a large flat raised metal + end, just slightly smaller than the battery diameter, so can be used in series.

Button tops are just that, a button or nipple looking thing on the end of the battery.


Protected and non protected Li-ion has nothing to do with the physical + end contact. Although you may find a trend that more protected batteries are button top and more non protected are flats. But I have some of both tops for each kind.


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## more_vampires (Jan 15, 2015)

*Re: Button tops vs flat batteries?*

Easier to put a flat top in backwards if you're not paying attention. I'm a fan of button tops for reduced screwups on my part.


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## mummel (Jan 15, 2015)

*Re: Button tops vs flat batteries?*

Thanks guys.


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## ChrisGarrett (Jan 15, 2015)

*Re: Button tops vs flat batteries?*



more_vampires said:


> Easier to put a flat top in backwards if you're not paying attention. I'm a fan of button tops for reduced screwups on my part.



A lot of modern lights have reverse polarity protection, so you're good on that front.

If a light has a spring contact at the positive end, or some sort of protrusion, then flattops work well for me, but my L3 Illuminations L10, my Icon Rogue 1 and my ShiningBeam I-Mini don't work with my flattop Sanyo UR-Ps, so I'm SOL. My EVVA protected Sanyos are just too long to fit in those lights, so I'm getting screwed both ways.

Chris


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## more_vampires (Jan 15, 2015)

*Re: Button tops vs flat batteries?*



ChrisGarrett said:


> A lot of modern lights have reverse polarity protection, so you're good on that front.



Even so, I always double-check polarity and hit them with a multimeter before and after charging. Sort of like checking to make sure the oven is off.

Makes me feel better.



ChrisGarrett said:


> but my L3 Illuminations L10, my Icon Rogue 1 and my ShiningBeam I-Mini don't work with my flattop Sanyo UR-Ps, so I'm SOL.



Tried one of those shim magnets?


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