Don't charge battery more than 2-3 hours, huh?

Factual Questions
1

Several ecig batteries I have purchased say to only charge them 2-3 hours, with a warning to not leave them unattended or charge them overnight. The chargers plug into a USB port on a PC or laptop and the battery indicates when it is done charging by turning off a LED, if it is fully discharged it takes longer and if not it takes a shorter amount of time. So it does seem like it stops charging when fully charged.

I’ve never seen this warning on any rechargeable battery before, obviously it is very easy to forget it is plugged in or accidentally leave it overnight.

Is this a real issue?

2

After some quick googling I found three reports of exploding ecigs, including one fatality.

But if the warnings are something you really have to worry about as long as you are using proper chargers, or just ass covering by the manufacturers, I don’t know.

3

I can see how maybe overcharging could damage a device. But the part I don’t understand is, if that’s so, and if the device can tell when it’s done charging (as evidenced by the light turning green), why can’t it just cut off the charging circuit automatically once it’s done?

4

The proper charger routine for Lithium-Ion cells is what’s called Constant Current- Constant Voltage( CC-CV). During the initial CC period a charger should gradually raise the voltage until the specified charging current is going in to the cell. Charger voltage climbs as the cell fills during the CC phase . Once the voltage reaches the maximum the cell should not exceed (usually 4.2 ±.05 volts for the typical Li-ion) voltage is capped. That’s the CV stage. During CV the current going in to the cell naturally dwindles down as the cell voltage gets closer to it’s max. A proper charger let’s that CV period go until current drops to low level and then shuts off. It’s not really that hard to implement.

The problem is that a lot of cheaper chargers implement something different which is “good enough” …until they aren’t. Sometimes when the light changes to show full charge they don’t actually shut off. Sometimes they exceed max voltage during parts of the charge routine. Sometimes they initially do the right things and terminate at a safe voltage …but then turn back on after a while and shove some more power into a full cell before terminating again. :smack:

Finding a charger that actually follows a good CC/CV routine and terminates properly can be a challenge. This recommendation seems to be a way to deal with the the fact that a lot of chargers are crappy. It doesn’t really protect you if a mostly full cell would terminate before the manual unplug time though.

5

These people are producing such a poorly designed and cheap product, and yet you put their poison in yours and other peoples lungs ?

6

The company that makes the hardware like the batteries is not the same company making the nicotine liquid, for what it is worth.

7

My cousin just got 3rd degree burns all over his hand when his e-cig blew up in his pocket. I don’t get why this happens when it’s not charging though. Probably a different issue entirely.

8

Straight nicotine has to be a lot better for you than tar and other carcinogenic combustion products from regular cigarettes, right? It’s still technically poison though, I’ll give you that.