really weird battery behavior!

[vapero]

hi guys please help me figure this thing out...
I been building my coils on rdas for a long time and I think I have good experience.

usually I build at .5-.8 and use mostly aw 18490's (enough amp limit for me)

but yesterday I swaped batteries (I have 4 18490's on rotation) and suddenly started to get burnt hits, I thought it was that I overstuffed my wick so I changed the cotton, still no improvement, today I changed the coil thinking that somehow that was the issue even if the coil would glow perfectly at .65 ohms, changed it to a identical one and still had the same issue, checked the voltage and the bat was at 3.77... changed batteries and now the issue is resolved

I always check battery voltage after charging and after using, this bat has been working great for the last 6 months

I checked everything and can't pinpoint the issue here

 

[Subdivisions]

sounds more like a wicking problem that suddenly resolved itself. I'd look more into that. You didn't really mention what tank/dripper/etc. you are using.

 

[pdib]

I was going to say a hot leg. Did you notice whether it kept making hissing sounds for a sec. or two after you released the fire button? (a little longer than you'd expect it to)

Wicking problem/hot leg

 

[edyle]

I guess you decided it was a battery issue because by the time you changed the battery, the taste was gone.

I figure some stuff got burnt somewhere and eventually burnt off. Once you changed the coil most of the problem was probably gone.

 

[Benzin]

If you put the same battery (the one you had burnt hits with) back, does the problem return?
If it does, check the voltage under load (remove the cap from your rda and attach the multimeter tips to the posts), and compare the under load voltage of that battery with another one. I bet the voltage is higher.

If the problem does not return when using the troublesome battery, then i agree with the others, it might be a hot leg.

hope this helps

 

[vapero]

this is really weird!!!
it wasn't a hot leg, it wasn't the cotton as I changed a few times while on that bat and had the same issue, it wasn't the coil as I changed also and didn't change, just went away when I swapped batteries (I took a vape with the bad bat then swap then took another vape with the good one and worked, I don't think that it was a coincidence...

I charged the bad bat again and came out at 4.24v, just used it and works great, I have no idea what happened

ps I'm using a igo-w rda on single coil

 

[edyle]

Yeah, it wouldn't be a battery problem; but since you decided to charge it, you can't check it again until you get it back down to 3.77 volts.


......

wait, are those the safe chemistry batteries or not?

benzin's suggestion is well worth trying if you can ; compare the voltages of the batteries under load;

especially with low ohm loads, the underload voltages are going to be significantly lower than the noload voltages.

 

[vapero]

Yeah, it wouldn't be a battery problem; but since you decided to charge it, you can't check it again until you get it back down to 3.77 volts.


......

wait, are those the safe chemistry batteries or not?

benzin's suggestion is well worth trying if you can ; compare the voltages of the batteries under load;

especially with low ohm loads, the underload voltages are going to be significantly lower than the noload voltages.

they are safe, AW from rtd or rdt vape I forget the name but they are good.
I'll give it a test undervolt once it gets there probably tomorrow as I don't want to mess with the rotation

 

[edyle]

I was just looking around and noticed a chart which showed in the case of nickel batteries, the internal resistance being lowest around the middle of the discharge state but higher at the fully charged and fully discharged state.

I don't know if that happens with lithium batteries also, but it could account for a battery seeming to run hotter at the medium charge state than at the fully charged state.