Nippleless 18650s don't work in my Vamo V2

[ThunderPumpkin]

I originally bought 4 Efest 18650 batteries for my Vamo V2s, 2 with nipples and 2 without. The 2 with nipples are what I've been using so far, and they work perfectly. And by the way, these are the Vamos with the big bottom spring and cardboard washer around the positive terminal.

I just recently tried the two without nipples, however, and they don't work in either of the Vamos -- no flashing light, and they won't turn on. When I put them in chargers (and I've tried 3 different ones) the light stays green. I assumed that meant that the batteries weren't properly making contact, so I put a drop of electrically-conductive solder on the charger's positive terminals to insure that the nippleless positive terminal on the battery was making contact, but this changed nothing.

Well, today I got 2 top-of-the-line Panasonic NCR18650Bs. I put them in the Vamos and... nothing! When I put them in a charger, however, the light does indeed turn red and they presumably charge (I'm guessing they were shipped partially charged.)

With the nippleless Efests, I figure I'd received a pair of DOA batteries. Now I'm not so sure.

With the Panasonics, however, since they're charging I figure the problem has to be with the Vamo, and specifically the contact between the nippleless positive terminal of the battery and the positive pin of the Vamo. An ad hoc sound test seems to confirm this -- when I drop an Eefest in from an inch or so above the terminal (with the Vamo upside down), I hear a nice metal-on-metal clink, but when I do the same with a Panasonic nippleless I don't hear anything like that.

Would it be safe to put a drop of solder on the battery's positive terminal in order to bridge the gap?

This is my preferred solution, since I have no idea where to get an appropriate magnet.

 

[crxess]

Simple mater of contact. Check that upper washer. If it is to thick get rid of it and fashion something thinner.
As long as you make contact with the top pin and the bottom spring, it HAS to work.
My V1 has no problems with Flat tops.

Do NOT induce Heat to your Batteries. Soldering batteries is tricky to avoid any damage. ( I do electric RC flight)

Hobby Shop - 2mmx6mm magnets will also work.............But a thin washer is best solution.

 

[NGAHaze]

+1 Yeah, definitely don't wanna solder your batteries. My V2 works fine with flat tops as well.

 

[ThunderPumpkin]

Thanks for the answers. I put the smallest drop of solder on the tip of the Vamo V2 positive post --a short brass or copper nail-like thingy-- and it's working now. I suppose the circuit board is seated 1 or 2 mm higher than it should be on this particular device and that's apparently keeping the post from contacting the battery.

There cardboard washer looks to be about 0.5 mm thick, and I don't think I could really put anything thinner on there, unless it were a few coats of nail polish.

So my question is, is this drop of solder on the Vamo post solution safe? I've been using it for about an hour now with no apparent problems (ready to hurl it out the window if need be), but I'd like to be sure.

 

[GaryInTexas]

I had to stretch my gold spring just a little when I first got my Vamo. No more problems.

 

[crxess]

Is your Screen aligned? if the Board has moved it should be evident in the screen and buttons.

Glad you got it functional!

 

[ThunderPumpkin]

Is your Screen aligned? if the Board has moved it should be evident in the screen and buttons.

Oddly enough, it seems perfectly aligned, so I guess the board itself is in the right position. Maybe the problem is with the post itself. It wouldn't have to be off by much... the drop of solder that fixed this is no more than 1 mm high.