Here’s a review on one exactly the same spec as mine:
My sample came with the standard 18650 tube, and per Hank, you must use standard length, unprotected batteries…
I tried a long Thrunite 3100 mAh 18650 and a Sofirn button top cell for fun, and the Sofirn button top fit fine, but the longer Thrunite cell was too long.
The Sofirn button top must measure measure 65.0mm or under to fit. The VCT6 button top is 67mm and is too long. I don’t know why the battery compartment has to be so tight? From rough measurements I took, both springs must be completely flattened to fit a battery spot on the 65.0mm length spec.
All my 14500 batteries are button tops, both the ones that came with their lights (Manker E03H II, Lumintop ToolAA 2.0 UV, and Wurkkos TS10) and the Vapcell H10s I bought afterwards. The problem is that lights with ‘physical’ polarity protection like the E03H II require a button top, otherwise the positive terminal won’t make contact.
I’m glad all my 14500 flashlights work with them, but at the same time sad that when the time comes to get myself a Hank D2, I would need to get a whole new set of batteries just for it
Why doesn’t Hank just add 2mm more to his battery tubes and a proportionally longer spring on the tailcap/head so his lights can work with button tops too?
That would be great! All my button-tops are unprotected, so no issues here.
Any other side effects from a driver with no spring, besides (obviously, I guess) not working with flat-tops anymore? (not a problem for me as I don’t have any)
The springs are easily long enough to cope with an extra 3mm body length in a D1V2 fitted with a GT-FC40. There are springs both ends that must get compressed almost flat- even with a flat top 18650 inside.
(I’m not sure if the LED / driver config makes a difference to the battery compartment space?)
I think theres a fine amount of space in the d1. I have one of every color, they’re all snug but not too tight. But I have a d4 thats pretty snug, so I get it. Hasn’t dented any flat tops yet tho. I’ll take springs over a solid button contact anyday tho
Manufacturers don’t add spring bypasses due to the risk of them coming loose and shorting out the light. The tail bypass isn’t really an issue, but if there is a bypass at the driver spring and it comes loose, it can cause a catastrophic short.
I just checked and there’s 67.5mm length in the battery compartment of my D1V2 with the GT-FC40 12V driver- that’s to the top of the post that the spring is wound around- not including the spring length on the driver.
The height of the spring on the driver post adds at least 3mm (bearing in mind mine has been squished big time), the spring in the tail cap stands 6mm high and you need to subtract it’s wire coil diameter (1.0mm) from the available length- as it’s soldered on top of the lip that contacts the body barrel.
So that’s:
67.5mm body space
1.0mm tail spring diameter
= 66.5mm maximum battery length with both springs squashed dead flat!
The springs have at least ~3mm + 6mm = 9mm height uncompressed. It’s not the spring length that limits using the button top- with 2.0mm difference in a button top vs flat top for a VTC6.
The springs will be almost completely flattened with only 1.5mm distance spare to share between them using a spot on spec 65.0mm flat top 18650.
Ya I meant to add “and the brass post/button it’s wrapped around”. My bad. The springs will be pretty much flat. The post on the boost driver is a tiny bit longer than the button on the linear one. It’s that little button that dented the button top I tried. That was on the linear driver
I only care about it having enough space to not dent a typical flat top tho. Some lights, 21700s especially, will dent flattops. As long as it doesn’t do that I don’t care what it does to button tops. Not sure why someone would use button tops if they don’t have to tbh. Except on the D2. That I can understand.
I’ve got at least one flat top that’s now a “concave top”. So I usually go for button tops as they’re more durable- plus they can be less problematic in some chargers (where the positive terminal doesn’t have a decent projection to touch the flat top.)
