need some help understanding batteries

[Rickajho]

I use red AW 18490 and aw 18650. So, say you fully charge a battery then let it sit for a day. When fully charged and it's at 4.20. What voltage should you expect it to be at the next day without being used? Meaning how much does it drop naturally from just sitting.

That depends on the age and the treatment of the battery. As batteries age out (or if they have been abused) they lose their capacity to retain voltage at rest. A brand new battery will most likely retain 4.2 volts at rest. But with use and time the resting voltage will drop further and faster. I just dumped some eFest 18350's that were long in the tooth - the resting voltage was dropping on this suckers to under 4.08 volts within an hour or so of the end of the charge cycle - with correspondingly shorter and shorter run times.

Just leave your batteries sit in the xtar at the end of the charge cycle for an hour or two and see what happens. A VP1 or VP2 continues to monitor the battery voltage at the end of the charge cycle. If you aren't seeing a significant voltage drop within two hours chances are you won't see a different voltage 24 hours later either.

Don't obsess over it either. A battery with a resting voltage of 4.18 volts may not be "perfect", it just means it's showing signs of being used.

Also, on the xtar is it best to charge at .25 or .50?

Well, either of the batteries you mentioned can be charge at up to the one amp setting with no problems. The theory is that the lower the charge current you use the longer the overall lifespan. The tradeoff is the lower the charge current the longer it takes to charge. I just the 250 mA setting almost all the time, unless I'm in a hurry to get batteries off the charger for some reason.

 

[Filthy-Beast]

All the batteries mentioned have a max charge rate of at least 2 amps or more. I don't bother to go down to 0.25, I charge at 0.5 that is at least 1/4 of max
and my batteries are never warm while charging.

 

[kinggirl]

ok so one of my batteries was fully charged at work on the xtar charger at 4.20 around 4pm. I took it off, let it sit, and put it back on the charger a min ago. It's reading 3.86. Is that normal?

 

[caup]

Definitely not normal.
After several weeks unused in a battery box, I wanted to refresh them in my older xtar wp2, but the led stayed green and indicated "full".
So they were definitely not below 4.1, otherwise they would have reloaded.
No exact science through, due to the older xtar.

 

[Tangaroav]

For me it would be easier to understand battery-life/ml of juice vaped , ( at a given coil built ).

My experience has been that my new AW 2000 mah will not last a full 6ml bottle vaping at around 1 ohm resistance. I am one of those chain vapers, +/- 15 ml/day and I have to use three batteries every day.

I only have 1 month of Reo experience. Can experienced Reo users confirm this is normal battery life ?

 

[caup]

For me it would be easier to understand battery-life/ml of juice vaped , ( at a given coil built ).

My experience has been that my new AW 2000 mah will not last a full 6ml bottle vaping at around 1 ohm resistance. I am one of those chain vapers, +/- 15 ml/day and I have to use three batteries every day.

I only have 1 month of Reo experience. Can experienced Reo users confirm this is normal battery life ?

That sounds right, especially if you change batteries early (on first taste change).
Make sure, your resistance is above .8 ohm, better above 1 ohm. AW2000 heats up and can't handle lower ohms.
You need higher capacity (or/and higher ohms) for longer vaping.

 

[Filthy-Beast]

ok so one of my batteries was fully charged at work on the xtar charger at 4.20 around 4pm. I took it off, let it sit, and put it back on the charger a min ago. It's reading 3.86. Is that normal?

No that battery is not good. I rotate through about 22 batteries, so they go a week or more between being charged and used. I just put one of my batteries charged a week ago in the charger and it's reading 4.2

 

[nerak]

ok so one of my batteries was fully charged at work on the xtar charger at 4.20 around 4pm. I took it off, let it sit, and put it back on the charger a min ago. It's reading 3.86. Is that normal?

I would toss that battery. It is broke! LOL!

Really, they should still read a full charge even after a couple weeks just sitting.

 

[pdib]

could be counterfeit batteries, kinggirl. did you get those AWs from a reputable vendor? (RTD. , KidneyPuncher)

 

[six]

It sure sounds like that battery isn't a good one any more... and that's almost certainly true that one cell is a goner from your description (likely that one of the 4 cells is losing its ability to push ions through the membrane - I'd bet that if you let that battery rest a week or two, it would lose a whole volt of charge) --- but, before you spend ten bucks on a replacement, clean the contacts on your charger - charge again - rest again - and check again. Just like the little bit of oxidization the REO contacts can get, the charger can get too and that can interfere with not just proper charging, but also the chargers ability to read the battery voltage. Regardless if that turns out to be an issue in your case, it's a good idea to clean your charger contacts every so often anyway.

On my Xtar WP2 II and my Xtar VP2, I charge 14500s at .25 or .5 (the WP2 II doesn't have a .25 setting) - 18350s always at .5 - and 18650s at .5 or 1 amp. -

Some of my other chargers have other settings and a couple of those chargers are way smarter than the others ... and the really smart ones (there's a Hyperion EOS at my work, for instance) don't play at all by the same rules as the others. They can and do far exceed the "maximum charge rate" of just about any battery they are able to charge at the beginning of the first charge cycle, and they finish charging at super low rates at the end of the final charge cycle... I only mention this to highlight the fact that charging can be a really complex topic. It isn't quite as simple as just feeding the battery whatever number of amps the switch is set to. And, I'd like to add that all three amp settings your Xtar VP has are all safe and appropriate for your AW IMR 18500s and 18650s... but do make sure it's on the 3.6v setting and not the 3.8.

 

[Funk Dracula]

Just leave your batteries sit in the Xtar at the end of the charge cycle for an hour or two and see what happens. A VP1 or VP2 continues to monitor the battery voltage at the end of the charge cycle. If you aren't seeing a significant voltage drop within two hours chances are you won't see a different voltage 24 hours later either.

Leaving batteries in a charger will either continue to slowly charge the battery (lower quality charger) or in higher quality chargers that have a true shut off, it will slowly drain the batteries. Even if the charger is unplugged, inserting batteries in it will slowly drain them. The VP1/2 will start charging the battery again when they drain down to 4.xx (can't remember the exact number) if you just leave them in there.

All the batteries mentioned have a max charge rate of at least 2 amps or more. I don't bother to go down to 0.25, I charge at 0.5 that is at least 1/4 of max
and my batteries are never warm while charging.

This. ^^^^

.25 is being a bit too conservative and unnecessary. That setting is there for 16430's and the such. A 2,000+ mAh 18650 doesn't flinch at 1A charge rate.

Also as six said: make sure you're switch on the Xtar is set to 3.6V and NOT 3.8, as that will over charge your batteries to 4.35V and kill them quite quickly.

What charger were you using prior to the Xtar? Some chargers have indeed been known to kill off the usability of perfectly good high quality cells.