What is your favorite method of converting flat top batteries to button top?

Good info Jerommel, thank you for posting it. :+1:

My goal is to make mine look as perfect as yours do in your pics up in post #4. :slight_smile:

Other - I prefer to go from house to house and explain the peril their little battery souls are in if they don’t convert to button top ism :wink:

I use piece of solid core wire and bend it into a ring and give it a tap with a hammer to flatten it some. Then i just solder that to the battery.

Nice one ‘Tjhosan’. :slight_smile: I never thought of that, thanks for sharing.

:+1:

Thanks for the instructions!

Have you tried doing tail cap amp readings with & without magnets ?
I used to use magnets but after finding that on an S70 on turbo running 2 x Liitokala 26650”s with magnets I was losing nearly 0.5A.
It may be of course that the magnets I was using had pretty high resistance but because of that I quickly over came my fear of solder blobbing cells & now solder blob if I need to turn a flat top cell in to a button top :+1:

I’ve seen magnets dent my cells .
not a fan of magnets

Solder blobs are simple …Add flux first then load up your iron till the solder is almost dropping off …it takes about a second to do .

Kicked myself for waiting so long to do it .
Seems like I was always hunting for a longer cell for lights that didn’t have a spring …messing with magnets or buying protected cellsbecause they were longer was just dumb .

+1……. I was in the same boat as you Boaz until not too long ago. I detest magnets…. :wink:

While I just received 10 flat tops, I was in need of a solution.

A quick search of the forum, and here I found some nice ways of getting the task accomplished.

Excellent topic, ALL. Several great solutions!!

Thanks to all who chimed in.

Update:

I just did all of mine. Works as explained.

I used to use solder and a washer of the right size, put the washer in place and then solder into the hole in the middle, it gives more strength than just solder,

Now I just buy the correct batteries with buttons :wink: .



Not many people use spacer, i dont know why
There is battery store at my place. And they have service convert from flat head to button head, 1$ for every 5 batteries
The result is good(at least to me)

I use some magnets and a little bit of glue to stop them sliding to the side.

Made a couple of these.
I just drop one in between the flat tops. Usually 2 batteries and usually the first battery in doesn’t need any help, at least in my flashlights.
The disc keeps it centered in the flashlight tube. Solder blob in the center. These are the thicker ones. I use the thinner ones most often.
Not a good solution for everyone but works for me. YMMV.
These are for 26650 sized cells :slight_smile:

+1 Agreed. I’m inspired looking at these guys solder pics.

I love this thread. As soon as 18650’s stop driving me crazy, they start driving me crazy again. Magnets are ok for me, but never anything more than just ok. Obviously they are not always a viable solution. In any of the 4p twist top configurations, they are definitely NOT ok.

I see a nice path to several solutions here and really just appreciate this thread and the activity here. I’ve always thought of doing the solder blobs as cumbersome and having an ugly appearance. However, with the given soldering tips and the posted pics, I can clearly see that it’s just the opposite.

Sorry, but:

With regards to decreased discharge performance, magnets resistance is not the real issue. The issue is in part related to the increase in contact resistance, as you are creating another non-stationary surfaces solid to solid contact. Increase contact surface, get wider magnets and or solder the stuff.

No, I'm not buying shitty button tops. That @#$% is an aftermarket add-on, very cheaply made. Crappy steel sheet spot welded with a puny nickel strip. Dreadful.

If I were to be handed button top cells without any real use for these ignominious stuff to be there, I'd probably grab my multitool and remove them (Oh! Already done in the past).

This may sound a bit dramatic to some of you, but not to me. I'm happy with it. If in need for protruding contact surfaces, I build my own to my standards.

^:)

how to build it? can you advice me?

I stumbled on a great way to make flat tops the same size and protected cells (sometimes your light just needs long cells)

Driver springs, or more specifically a stiff driver spring that RMM has in his shop. tin the spring first then a quick dab of solder once on the cell and bingo a flexible sized cell that fits protected and button top sized lights.

I found those on Aliexpress which might a nice option for soldering

Definately cheaper than the brass buttons from Fasttech or Kaidomain

https://www.aliexpress.com/item/50pcs-lot-4-5-6-7-8-10m-Yellow-Copper-Round-Flat-Metal-Spacer-Beads-Fit/32799436603.html
https://www.aliexpress.com/item/50pcs-lot-5x2-5mm-Vintage-Original-Brass-Loose-Spacer-Beads-Round-Flat-Beads-Nepal-Beads-fits/32807367148.html

Even gold plated ones

https://www.aliexpress.com/item/100PCS-24K-Gold-Color-Plated-Brass-Wheel-Spacer-Beads-Various-models-High-Quality-For-Jewelry-Making/32807065998.html