18650 Battery Case Holder, 10 Pcs 1 Slots x 3.7V DIY Battery Storage Box, in Parallel Black Plastic Batteries Case with Pin for 1 x 18650, by Ltvystore

This is my favorite holder for 18 650 cells. It holds your battery nice and snug like they should and you may need to use a small straight blade screwdriver to pop them out if you need to but for my application that's not a big deal because I would only be changing them if a cell were to go bad. The tabs on this are designed 2 solder to a circuit board but can very easily have wire soldered to them. For instance I have the three battery holder block soldered in series on four of them making a block of 12 18 650 batteries with an output voltage of 16.8 volts. If you plan on buying these and putting batteries in and out of them all the time you may want to bend the contacts in a little bit or I should say out so the battery fits a little bit looser but besides that these are excellent and the plastic used is very durable. Also if you are planning on some pretty heavy current draw from your batteries these will work great. My average draw / cell is 3.5 amps and no issue with heat like I would with the spring type.

The holders are hard plastic and have quite stiff contacts that solder well, thats the good. The bad is how to mount them. the small screw holes are not countersunk and cannot have any screw head sticking up, at all, or the battery will not fit in to seat on the contacts. So your guess is as good as mine, drill new and countersunk holes for verrrrry tiny screws, I guess so. Too bad the seller did not consider how to mount them. The existing holes are useless.

3 18650s side-by-side in the 3 slot version bump right into the plastic dividers that run from top to bottom in the holders. At least in my case, I had to cut them out for the cells to fit properly. They do work, but the terminals are also not rated for high power, so keep your loads below like 2 amps, maybe an amp. The terminals are more meant to go into a PCB, and the slots are not connected to each other (independent with all +'s on the same side as marked).

These are not good for tight spaces. Tried to use them for an 18650 battery mod in the SkyController 2 and it was too tall. Even after removing the extraneous plastic at the top of the poles with a cutter it was still too tall. This is because it has a thick plastic bottom below the batteries. Would recommend the Keystone model with holes at the bottom instead if working in tight spaces -- that will get you the lowest possible height.Like the other reviewers mentioned, the battery fit is tight and taking batteries out is somewhat difficult.

These are great, maybe a bit tight. I hot glued them together then soldered a positive & a negative lead along the bottom edges making a 1s15p holder to speed the charging of my 18650s. Works like a charm. Probably going to duplicate the setup soon because even 15 at a time isn't as fast as I'd like with > 1000 to do.

Review of the 3 slot 18650 battery holder. Good quality holder that appears to be for the 18650 button top vice flat top battery. Flat top will not fit unless you use pliers to permanently squeeze the tabs at each end; even then it is difficult to fit the battery. Button top 18650 can be fitted without smashing tabs, but then cannot be easily removed without a pry tool. Tab to tab distance is 61.5mm without battery and will compress to 63mm with moderate force. Battery length measures 66.5mm; that's 3-5mm short for fitting a flat top battery into the slot.

I just received these double 18650 battery holders, along with some single holders. I broke the first holder by simply trying to put the batteries in. The problem appears to be that their length is slightly too short. One way around this, is to slightly compress both electrical tabs on each end before trying to insert. Once I did this on the second battery holder, it seemed to minimize the stress on each end. These are not super high quality holders, so be careful with them.

Unfortunately, I could not use these because I have Protected Button Top 18650 batteries. I've tried squeezing the metal contacts to give the batteries more room to fit but still just 1 millimeter too long. These holders were made out good material and had nice solder leads.

Everything works.I wish the tabs were easier to solder.Strong connection it does weaken over use compared to spring.It's difficult to remove battery. You could use something under the battery to aid in remove. After some use it does get easier to remove.