Battery Configuration Question

[billiam]

Hi. First off I don't intend to try this. There was something Phil B. was reviewing that just got me wondering. He was reviewing a mod with a battery slot big enough to hold 2 18350s stacked or 1 18650. The mod I'm gathering parts for will have 2 battery slots big enough to do either. In this image: I have one slot stacked and one not. Could this fry the lone battery?

I know If I put a fully charged battery and a near dead battery in parallel like this they will equalize, which brings up another ? how fast does this happen? If it's too fast, could that cause some damage of some sort? To the main ?, will the stacked batteries try to pack a few more volts into the lone battery trying to equalize, damaging the lone battery?

Thank you to anyone for any clarification.

 

[billiam]

Well I realized the answer to my own question. When you think about it on a larger scale, say a 12 volt car battery and a 6 volt lawnmower battery, it becomes obviously insane to hook them in parallel with each other. I would expect the same disaster with the set up I diagrammed. Never do this. OK?

 

[MorpheusPA]

Good for realizing that. The 7.2 volt paired batteries will try to charge the 3.7 volt single battery and things are going to get very ugly a lot faster than you might think they would. Lithium batteries really, really hate uncontrolled charging, and charging at too high a voltage. This manages to combine both of these.

Theoretically you could parallel two 3.7 volt batteries, but they'd have to be well-matched and I'd personally avoid doing so. I dislike stacking or side-stacking lithiums under any circumstances. Lithium is touchy and you have to be very careful.

 

[billiam]

Hi MorpheusPA. What I have here is a gutted Smok Tech Groove. It's a mess because I just threw together something to make it work with an 1100 mah IMR battery as soon as they came. A couple of weeks after that I broke the circuit board in my 900 mah Ego battery (a "short" story I won't go into here ) and thought what the heck and stuck the battery part in there also (in parallel). I haven't had any noticeable problems. Sometimes I unplug the 1100 battery so that I'm not tethered to the wire but try not to let the Ego discharge too much farther than the 1100. After reading your reply, I will be doubly cautious of this.

Thanks for your reply & Happy Safe Vaping to All

 

[MorpheusPA]

BillIAm, you just managed to scare me a little. Said batteries are unmatched, and I'm never inclined to trust one from a commercial product (the eGo) to be anything other than the cheapest possible model.

I'm going to presume you have good homeowner's insurance. If not...please get some.

That may sound flip, and it is, a little. But that setup has the potential to do some really ugly things to you and the things you own.

 

[billiam]

Don't worry Morpheus. I never leave any of my batteries charging unattended. I check for heat often. I've never noticed more than the slightest bit and that's only when charging. I've read the horror stories and keep a close watch on them.

Thanks for the concern.