Why do my APVs think freshly charged batteries are dead?

[Poeia]

Equipment
I'm switching away from tubes and bought three variable voltage box mods, each built by a different person. I also have a couple of 3V box mods.

One VV came with a pair of TrustFire 14500s. I bought another of those plus 2 pairs of EH brand IMRs.

I'm primarily using Vivi Novas, mostly at 2.4Ω, but am having the same problem with standard resistance Joye 510 atomizers.

I have 3 chargers that can handle 14500s -- a TrustFire TR-003 (which can do 4 batteries), an UltraFire WF-139 ("rapid charger" for 2 batteries) and generic charger that I've been using for almost 3 years.

The Problem
All was fine for a couple of weeks but now, when I take my freshly charged batteries off the charger and put them in a VV mod, I get one hit (if I'm lucky), then the mod thinks the battery is drained. I put it back on a charger and the light goes green within a couple of minutes.

It doesn't matter which VV mod I use, which set of batteries, which charger or which atomizer/cartomizer. It happens every time.

I've split up the TrustFire pairs and am using them on the 3.7V box mods and they work fine with the same atomizers/cartomizers that just failed on the VV (regardless of which charger was used.) I also tried the IMRs in the single battery units and they worked too.

Any ideas why it's doing this (other than for the fun of driving me nuts)?

 

[recidivus]

Not 100% sure, but I recall reading that protected batteries bugger up on VV units. Something about not being able to handle the draw and it trips the protection. Do you have a multimeter to test the batteries when they come off the charger?

 

[Poeia]

Thanks. The IMRs are doing it just as much as the protected Li-ion batteries so I don't think that's the problem but it's a good idea about the multimeter. I have one, I've been incompetent about using it but I guess I'll have to learn.

By the way, the atomizers and cartomizers all work fine in basic 900mAh eGo batts as well.

 

[WillyB]

Are these VV's made with plastic 3AA battery boxes?

 

[Poeia]

Yes, although each are somewhat different -- the backs aren't interchangeable. They are basic box mods that I don't have the skill to make for myself.

 

[WillyB]

Well that is probably your problem. The positive connectors.

Take a peek at this.

Those plastic retainers will bump up against the body of the battery, and depending on the size of the nipple (or on flat tops the lack of one) hold it back from making firm, positive contact.

In days past some folks would build up the positive terminal with a layer solder, some would just remove the shoulders altogether. In the top one you can see how it's also concave.

When I used to build such things I'd bend them a bit to make them convex and shim the back with whatever I had handy.

 

[Poeia]

Thank you. That makes sense. What was making it so perplexing was that all three were from different makers but, looking at them, they all have that little bit of plastic.

I assume getting batteries with very raised nipples will help -- I need more batteries but was waiting to order them as I didn't want to send good money after bad -- and, if that doesn't work, I can attack the little shoulders with a file (I don't solder.)