Good-quality holders for 18650 batteries

Another mini-review of various useful little things. This time, it’s holders for one or two 18650 batteries.

I ordered the holders from two different sellers. I’ll link to both below, but they did have a few things in common: very fast shipping and decent packaging—in one case, excellent packaging.

As you can see in the photo, some came in resealable bags with extra foam protection, while others came in a cardboard box.


First, the single-cell holders. I ordered them from AliExpress: three lots of 10. Each lot cost $3.54, but with shipping the total came to $15.20 for all three lots (shipping wasn’t free).


The double-cell holders came in a sturdy cardboard box, as I mentioned above. That earns the seller an extra point.
There are 20 in the lot. I bought one lot; here’s the product link. It cost $17.18, with free shipping.


As with the previous batch, I have no complaints about the molding quality. I’ve ordered holders like these several times, in every size from 1x to 4x, and never had any problems.



All the holders except the single-cell ones are marked for both parallel and series connections.


There is one minor drawback: the tabs are rather thin, so high currents could cause problems.


The contact springs, on the other hand, are excellent: they’re fairly wide and grip the cells very firmly.


A few dimensions. The last photo was taken with the contacts uncompressed, but keep in mind that the springs are very stiff.


In my previous review of similar holders, I posted a dimensioned drawing. It applies to these holders too, with the obvious caveat that the drawing shows a 4x holder, while this review covers 1x and 2x holders.


Branded batteries without protection circuits fit perfectly. But because the contacts grip so tightly, it’s best to insert the positive terminal first, then the negative one.


Unbranded batteries may not fit, and protected batteries won’t fit at all, so keep that in mind.
Even branded batteries can sometimes be tricky to remove. For example, when I pulled one out, a tab tore its insulation. That’s exactly why I recommend always removing the negative terminal first, then the positive. I was holding the holder in midair while removing the battery, and still ended up damaging it.


As I mentioned above, the tabs that the wires are soldered to—or that are used to mount the holder on a circuit board—have a fairly small cross-section. At currents above 5 A, this could cause problems. I once tried drawing 14.5 A, and the contacts nearly melted through the plastic housing.


I ended up using intermediate tabs at first, then eventually soldered the wires directly to the top. With the latter setup, I was able to draw 20 A without any problems. Used this way, these holders can handle heavy loads, for example in a cordless drill.


As a bonus, here’s a thermal image of a battery under a continuous 20 A load, installed in a holder similar to the one reviewed here.


That’s about it. I can definitely recommend both the holders and the sellers (they’re two different stores).

And as a bonus, here’s a short video about the item reviewed here and a few other useful things.