Holders for four 18650 batteries

Another mini-review of 18650 battery holders, this time for four cells.


I recently published a review of some triple holders, but that seller only had versions for 1, 2, and 3 cells. I also needed four-cell holders, so I ordered them from another seller, which means a separate mini-review :)


The seller surprised me a little. First, the packaging was excellent; also, he shipped two orders in one parcel. I had ordered two items from him but hadn't noticed they were from the same seller. I found out later, when I added the tracking numbers to my tracking system and it notified me that the two numbers were identical. When I picked up the parcel at the post office, it turned out he'd put both orders in one box and provided a single tracking number. Of course, it would have been better if he'd asked first, just in case. But in this case, I was fine with it.


One order consisted of ten 4x18650 holders, priced at $0.67 each. Shipping to my country was $1.37 for one, then an additional 25 cents for each extra one, so 10 came to $10.79.
The second order was for enclosed holders for 2x 18650 cells, priced at $0.41 each. Shipping to my country was $1.37 for the first one, then about 50 cents for each additional one, so 10 came to $10.10.

When shipping to Russia, the first item costs less to ship, but each additional one costs a little more. An odd seller, that's for sure.


I'll talk about the enclosed holders next time; today we'll look at the regular ones. They're packed compactly and snugly, so nothing rattled around or got scratched.


These holders are made by Blossom. I buy them very often, partly because this review won't include resistance measurements: their quality is very consistent, and I measured it recently anyway. I did measure these too, of course, but the results were the same as for the 3x18650 holders I showed recently.


As with the previous ones, these holders are universal: each battery has its own terminals, so you can connect them in parallel or in series. The holder itself is marked for both parallel and series connections.


The holder is almost as long as it is wide.


Last time I included my own dimensioned drawing, but this time the seller's page had a full set of dimensions, including the PCB mounting dimensions. The image quality isn't great, of course, but you can see everything you need.


Still, comparing it with the 3x18650 version makes it clear that it's the same thing, just larger :) Both holders have slots for a strap (presumably) to help pull the batteries out. In this photo, they're the two slots on the left and right of each holder.


Apart from the good points, these holders share the same drawbacks. You can't fit batteries with a protruding positive terminal and a protection circuit. This is because they use solid contacts rather than springs, which have more travel but also significantly higher resistance.


The springs are very stiff, at least when new, although I also have an old holder and its springs aren't much weaker.
If you remove the positive terminal first, you can damage the insulation, as shown in the photo. In fact, the holder being reviewed damaged this battery, so remove batteries from the negative end and do it carefully.


That's probably all. I have no complaints about the product, the seller, or the packaging. I buy these holders often and in quantity; in my opinion, Blossom offers very good quality at a good price. However, keep in mind that you can't draw much current through the terminals intended for soldering to a circuit board. If you expect to run substantial loads, it's better to solder to the bend in the heavy-duty contact instead.