Battery Safety Questions

[raspberryblu]

I know this subject has been discussed ad nauseum, but I would like a simple list of recommendations on overall battery safety with regards to use and charging. I've done tons of research on ECF and the information does seem to be spread out all over the place. I was hoping I could get specific answers to my questions below.

18650's

I use VTC4's with an intellicharger I4. I use them on Vamo V5's and Sigelei 20W's. I build my own coils on my protanks with ohms ranging between 1.6 to 2.5. I normally do 9 wraps of 30g Kanthal on a 1/16 drill bit as my form. I'm using cotton wicking. 1.6 is the lowest I feel comfortable going. My questions on the 18650's at this point are more related to charging than actual use as the ohms and wattage I'm using are well within specs for the battery (6-8 watts depending on juice).

1) I've heard varying opinions on how low the battery should be allowed to go before recharging. Both my Vamo's and Sigelei's indicate low battery at about 3.3v. Should I be charging before then?

2) Since the batteries are all fairly new, they indicate 4.2v when fully charged. Should I be charging them to maximum, and if not what is the maximum time they should be left on the charger?

3) At what point would the battery be considered unsafe to use as they obviously degrade over time, and would a drop in voltage after being fully charged be a good indicator of when to get rid of the battery?

4)What battery tester would you recommend?

5)Using the intellicharger, the batteries get a little warmer when charging multiple batteries at a time. Is this normal? They are by no means hot, but there is a difference in temp as opposed to charging one by itself.


EGO Types

Although we primarily use our mods at home, we do have some Ego type batteries that we use out and about town. We never charge any of our batteries unattended, but whether you're home or not an exploding battery pretty much amounts to a bad day.
1) The little 510 chargers that I have go green and *supposedly* shut off when the battery is fully charged. Is heat an indicator that the battery is being over charged? In other words, assuming I'm sitting right there, how would I know that the battery is being overcharged?
2) What is the maximum amount of time these batteries should be on the charger, green light or not?
For those of you that take the time to answer these questions, your help is much appreciated.....

 

[Baditude]

1) I've heard varying opinions on how low the battery should be allowed to go before recharging. Both my Vamo's and Sigelei's indicate low battery at about 3.3v. Should I be charging before then?

Since you are using the Sony VTC4's, these are one of the newer hybrid batteries. "Hybrid batteries are capable of a much lower minimum discharge voltage before causing physical damage to the battery. The battery is capable of being discharged to 2.5V whereas IMR & ICR batteries have a cutoff around 3.2V." - http://www.e-cigarette-forum.com/forum/blogs/baditude/5162-11-deeper-understanding-mod-batteries-part-ii.html

I would trust the over-discharge safety circuitry in your PV's to know when to recharge your batteries. The problem of over-discharging is most common when using a mechanical mod and not being experienced enough to notice the drop off of the vaping experience when the battery voltage becomes too low. Mech users should have some type of way to measure battery voltage to prevent over-discharge.

2) Since the batteries are all fairly new, they indicate 4.2v when fully charged. Should I be charging them to maximum, and if not what is the maximum time they should be left on the charger?

Charge them to 4.2 volts. The Nitecore Intellicharger is an intelligent charger, so it will stop charging after the batteries are at 4.2 volts. However, safe battery practice dictates to still remove the batteries after reaching a full charge whether the charger is an intelligent charger or not. This just gives a little bit more peace of mind.

3) At what point would the battery be considered unsafe to use as they obviously degrade over time, and would a drop in voltage after being fully charged be a good indicator of when to get rid of the battery?

A healthy older battery should always charge to 4.2 volts. However the older battery will not hold the charge as long as when new. It's a matter of common sense as to when to replace the older battery for a new one.

I have a couple of two year old AW 18650 IMR 2000mah batteries which are just now starting to show their age, meaning they are only holding a charge for 12 hours use as opposed to 20 hours when they were new.

4)What battery tester would you recommend?

You could purchase an 510 inline voltage meter or a digital multimeter.

On hindsight, your regulated mods have a built-in voltage meter.

5)Using the intellicharger, the batteries get a little warmer when charging multiple batteries at a time. Is this normal? They are by no means hot, but there is a difference in temp as opposed to charging one by itself.

I use a Nitecore i4 myself, and my batteries or charger do not get warm, even while charging four batteries simultaneously. Others may check in here with their experiences, but none of my chargers (an older Pila, Xtar WP6 II, Nitecore i2) allow a battery to become warm. All of my batteries are AW brand IMR's.

1) The little 510 chargers that I have go green and *supposedly* shut off when the battery is fully charged. Is heat an indicator that the battery is being over charged? In other words, assuming I'm sitting right there, how would I know that the battery is being overcharged?

You shouldn't feel heat in a eGo battery, that's a red flag that the battery is defective. Unless you use a digital multimeter to check the voltage output of the battery, you don't know if the battery is fully charged.

An eGo battery charger "should" stop providing a full charge when the green indicator light appears. However, it will continue to give a "trickle charge" to keep the battery voltage at 4.2 volts. The longer a li-ion battery receives a trickle charge can affect the overall longivity of a battery's expected lifetime. This is why it is recommended to remove a battery off of an eGo charger as soon as the green indicator light comes on.

2) What is the maximum amount of time these batteries should be on the charger, green light or not?

I would remove them within an hour after the green light appears. Leaving a battery to charge overnight while sleeping decreases the overall expected lifetime of the battery.

I recommend charging all batteries on a flame resistant surface. I charge mine on a stove top. Other options would be a marble countertop, metal baking pan, or pyrex dish. Statistically, most battery incidents occur during battery charging.

 

[raspberryblu]

I appreciate the response baditude. I'm so freakin paranoid about batteries now it's cut in to my enjoyment of vaping....LOL I took a battery off the charger today because it felt lukewarm instead of cold like when I first put it on and now I noticed a dark spot on the side of it?