Genuine Eleaf iStick 40W TC Temperature Controlled Box Mod, No e Liquid, No Nicotine (Blue)

Robust, holds its charge well.

I use them all the time for vapes

Excellent

Don't get me wrong it's a really good battery. There are to reason why I've given only 4 stars1. after a while the screws are loose and it's almost impossible to tighten.2. While charging the screen does not give a real indicator about the battery level

Good price for good product

So I have two of these, one given as a gift and one I bought from a shop. Both are the same battery, blue, "iStick TC40W". And both of them are non-functioning within 2 months of purchase. My father also has 2 bought here on Amazon, one of which was useless within 2 months (and the other seems to be going the same way within 3 months of purchase). Why do I say non-functioning? Because we cannot charge them.Here's the problem. MicroUSB is notoriously bad as a connector; no matter the quality of cable, whether it's a PS4 controller or a Wacom, in short order plugging it in and searching for that one angle of insertion that will allow charging to occur becomes the standard routine. This is bad enough even when the implementation is done well.But here it is even worse. The above happened quickly, but then over a short period of time the MicroUSB connector inside the battery starts to be pushed backwards INTO the battery. This has happened to both me and my father with these iStick ones. Eventually they end up so far back that the MicroUSB connector can't even reach. At no point do you hear some kind of snapping inside it, so my GUESS is that the female MicroUSB is simply glued down and that wears out over use.When this happens, the battery becomes useless. Well, no bother right? You could just open it up and reseat the connector. Except they use some tiny 6 pointed star of David screw. The sort that you can't unscrew with a normal screwdriver or even a pointy knife. So you'd have to buy a completely non-standard screwdriver.I discussed this with some other people who I would describe as "vaping-zealots" (the sort who refuse to accept any criticism of vaping paraphernalia). They told me that because it's MicroUSB, I should be using a "charging dock" which prevents odd-angled insertion. Which sounds great, except if that is necessary to even use the product for more than a couple of months then it should be included in the box. And also, I can't find one available for purchase anywhere. So my only option is overly-careful insertion of the charging cable by hand, which doesn't actually slow down the damage to the port.As a comparison, I also have a battery from another company that says "Vapefantasy" on the side. I don't know who made it. It's very similar, but the MicroUSB port is on the SIDE instead of the BOTTOM. This other battery has all the typical MicroUSB problems (it's just an awful connector), but because it's on the side it has nowhere to go inside the shell, so doesn't get pushed back out of reach of the connector. And its screws on the bottom are philip's head. Just like the iStick you find yourself having to tenderly spend 5 minutes moving it to find the one spot where charging can occur, but it never becomes COMPLETELY non-functioning.I ended up in a situation recently where I couldn't get either iSticks to charge. Borrowed one of my father's iSticks, and couldn't get that to charge either. That's 3 batteries of the same make and model, which can't be charged within 2-3 months of purchase, because of the implementation of the MicroUSB port. Since I'm still addicted to nicotine, I had no other option than to buy a pack of cigarettes to tide me over until I got back home and could get the other non-iStick battery. Yes, these iStick batteries are SO unreliable that I ended up having to momentarily give up on giving up. You might say that that is a me-problem, which is true, but the point I'm making is that a totally normal usage for this equipment (replacement for smoking) is not something you can rely on because of poor product design.Looking at the iStick, the only thing I can think is the term "Planned Obsolescence". The design choices legitimately only make the battery worse and more likely to fail, forcing you to buy a new one sooner. This is EITHER incompetence in design OR maliciousness towards the consumer on the part of the manufacturer. In any event, it makes me want to find another product.I would not buy this product again unless:- They redesigned it to use USB C ports; or- They ship each battery with a dock shaped to reduce the natural stresses which MicroUSB can't handle;This battery is a little over £30 right now. Both I and my father have 2 of these each. That means we cumulatively spent about £120 on these batteries, of which £90 was wasted within 2 months, and the whole £120 was wasted within 3 months.I would rather spend £50 or £60 on one battery that has a USB C port which is internally held down by a screw or something. Stop skimping out by using MicroUSB. It is an utter plague.I will not buy this product again, nor recommend it.

I have used this product for a few years and I am very happy with it.

Smart