Why 3.7v batteries? and temporary workaround to shipping ban on batteries

[ardev123]

The shipping companies are refusing to ship any Li-Ion Battery. The problem with the batteries we use in our APVs is that they are not easily bought from supermarkets etc.


First of all, why did the manufacturers use 3.7v non-standard size Li-Ion batteries for APVs? They could've easily designed their circuitry around the operating voltage for NiMH or NiCd rechargeable. 3.7v Li-Ion 18350, 18650, 14500 are extremely limited in availability. In my country, the only way to source these batteries are online and the shipping ban makes the experience stressful on top of the already stressful experience of buying electronic cigarettes online and shipping them here where it is already banned.


Since my current stock of batteries are going down rapidly and my order from Singapore (the only place I can purchase batteries online at the moment) will take a month to reach me, I started thinking of a temporary solution that can keep me vaping until I sort out the battery shortage issue. I looked everywhere for 3.7v batteries and the only ones available locally and practically everywhere are Cell Phone batteries. Almost all cell phone batteries operate at 3.7v and are the same Li-Ion compound used in the 18650s etc. Some are Li-Polymer but apart from the mAh boost, they are practically the same.


So I went to a phone shop and got me a couple of these Nokia Batteries:





They are extremely cheap if you get the non-original sort. Took out the soldering iron and soldered the male on these JST Connectors




on the batteries and female on a spare single Li-Ion battery charger for 18650, 18350, etc. which came free at one purchase I made.




And there you have it a 3.7v Li-Ion battery stocked practically everywhere (including supermarkets) and cheap (I got them for $10 a piece).


I had a SmokTech VMax with a broken button lying around so I stuck it to a project box, soldered two female JST connectors in serial (stacked) to the +ve and GND and I am enjoying a full day per charge on these Nokia Batteries!

 

[JJOOHHNN]

The shipping companies are refusing to ship any Li-Ion Battery. The problem with the batteries we use in our APVs is that they are not easily bought from supermarkets etc.


First of all, why did the manufacturers use 3.7v non-standard size Li-Ion batteries for APVs? They could've easily designed their circuitry around the operating voltage for NiMH or NiCd rechargeable. 3.7v Li-Ion 18350, 18650, 14500 are extremely limited in availability. In my country, the only way to source these batteries are online and the shipping ban makes the experience stressful on top of the already stressful experience of buying electronic cigarettes online and shipping them here where it is already banned.


Since my current stock of batteries are going down rapidly and my order from Singapore (the only place I can purchase batteries online at the moment) will take a month to reach me, I started thinking of a temporary solution that can keep me vaping until I sort out the battery shortage issue. I looked everywhere for 3.7v batteries and the only ones available locally and practically everywhere are Cell Phone batteries. Almost all cell phone batteries operate at 3.7v and are the same Li-Ion compound used in the 18650s etc. Some are Li-Polymer but apart from the mAh boost, they are practically the same.


So I went to a phone shop and got me a couple of these Nokia Batteries:


View attachment 301849


They are extremely cheap if you get the non-original sort. Took out the soldering iron and soldered the male on these JST Connectors

View attachment 301850


on the batteries and female on a spare single Li-Ion battery charger for 18650, 18350, etc. which came free at one purchase I made.

View attachment 301851


And there you have it a 3.7v Li-Ion battery stocked practically everywhere (including supermarkets) and cheap (I got them for $10 a piece).


I had a SmokTech VMax with a broken button lying around so I stuck it to a project box, soldered two female JST connectors in serial (stacked) to the +ve and GND and I am enjoying a full day per charge on these Nokia Batteries!

Because of energy density.

 

[ardev123]

Because of energy density.

Brand-name NiMH batteries have comparable energy density to Li-Ion if i'm not mistaken

 

[UncleChuck]

Brand-name NiMH batteries have comparable energy density to Li-Ion if i'm not mistaken

It's all about capacity, voltage, and how much current the battery can safely handle.

Original ecigs were all cigalikes, roughly the size of a real cig, Nicds or NiMh wouldn't have nearly the performance needed in such a small cell.

Then came Mods, mods originally just being re-purposed flashlights and other tubes. Back then people were using all sorts of batteries, some using the 4xAA battery packs with NiMh and the like in box mods. 16xxx and 18xxx batteries were already being used in the flashlight world (for the same reasons) so it was an easy transition to ecigs. Over time the 18xxx series of batteries have become somewhat of a standard when it comes to non ego and non cigalike devices because they have a high capacity, can handle high current loads, and operate at a higher voltage than a 1.2v NiMH or NiCd cell.

In order to match the voltage of a single 18650 battery you are going to need to run at the very least 3 cells in series, probably 4 cells to take into account voltage drop from load and draining batteries. Now you have 3-4 batteries to deal with instead of one. And since series configuration of batteries doesn't increase their current handling abilities, you are still limited on current by a single cell. Meaning your amp limit will be the limit of a single AA nimh cell, which is not very high at all.

You could very well design the atty to work at a lower voltage, but to do that you are going to have to reduce the resistance of the coil, which quickly begins to drastically increase the current demanded of the battery, which again AA NiMh cells can't handle.

Not to sound callous or anything, but your situation probably doesn't rank very high on the radar of ecig manufacturers. The vast majority of ecig consumers have fairly easy access to the cells we are currently using, and they work better for our purposes than anything else that's reasonable (nothing exotic in other words) so they likely don't see any need to start using other batteries.