Making good 18650 cases bombproof... ish. (Pics)

Hey guys, I’ve been lurking around here for a little while, both before and after I made an account here. I never posted here because, idk, I guess I wanted my first post to add to the discussion. I’ve been using the Waterproof 18650 cases from Dealextreme ( At just over 2 usd a piece, they are very rugged for the price, and after numerous MTB crashes into puddles, logs and what have you, the waterproof aspect has been pretty true. They are not without fault however, they leave a large amount of space around the batteries:

Because of this, whenever I have spare batteries in the case and I’m biking or running, all I hear is clack, clack, clack. This sound is highly irritating to not only myself put anyone in earshot of me, and honestly I don’t always want everyone in the area to hear me if I’m riding alone in the woods. The impacts also hurt the casings of the batteries, one of my TF Flames already needs to be covered in tape. So long story short I decided to fix this.

I had some 1/4 inch adhesive high density foam stripping I had left over from a gig that I purchased from McMaster-Carr and I decided to use the to pad the case.

Before dealing with the foam I attached red electric tape to both the inside of the lid and the outside of the body. Its a small thing many of you already do, but its too useful to ignore. If you don’t know, one puts the batteries in the case with the negative end under the tape. When a discharged battery is place back into the case the positive side goes on the taped side. This allows one to have both full and depleted batteries in the same case without confusion. A (+) showing is full and (-) is dead, simple stuff.

Now back to the foam. Each case needs two strips of about one inch in length, and three at about two inches. Because I cut these by eye here’s two differently sized pieces with a case and an 18650 for scale.

Time to add the strips. The layout is pretty simple. Word of warning though. If you have the strips from Mc Master, DO NOT MESS UP. I can’t really stress this enough, I have never met a more unforgiving adhesive in my life. The second these strips touch anything they are now a part of it forever. Even a glancing blow will cause them to stick with the might of a thousand gorillas. The short strips (protects the ends) go on either end of the case. Try to center them on the walls from side to side. Two of the long strips go into the centers of each battery well, at the flats (prevents rib gouging). The last long piece goes in the middle of the lid (Prevents the batts from hitting each other).

Do this for all of your cases, and now you have shockproof, rattle-free, 18650 cases of win.

Apologies for my bad grammar if you notice any errors, too tired to sleep, too tired to proofread.

Welcome Aboard !!

Nice first post !! :bigsmile:

Think I may just have to borrow your idea… :wink:

And TY for the walk through of ... shockproofing (is that a word?) those 18650 cases.

I mostly agree with you on all counts: Rugged - check, cheap - check, waterproofish - check, makes loud noise when moving - check! :-)

I've never gotten around to do anything else about it but stuff some bubble wrap in there but I see how this is more forgiving on a windy day in the fields.

Nice first post and I hope you have fun here - I know I do ;-)

Welcome to the monkey house, UnfourtunateJones!

very useful if you do canyoning on night and need a backup of batteries xD
ty for share

welcome jones :slight_smile: