AW IMR 18350 question...

[frazam]

Hi, I use 18350s and I recently purchased a couple of AW IMRs. I read that they should not be used when undercharged (?).

When I use them, I change them after about an hour of moderate vaping for fear of overusing them and causing permanent damage. But of course, this is very inconvenient for me. My question is, how long does a single AW IMR 18350 last typically? If say, I take 2-3 puffs every 5-10 minutes? How do I know when to change them out? I don't want to use them till they're dead of course. Any suggestions on how you guys do it?

 

[jkoppk]

When I use them in a mechanical mod I switch them when I notice a drop in the vape my mod is putting out.

 

[Sicarius]

The only way really is to learn what your run time is for your batteries. You could always measure the voltage occasionally to make sure you get a reasonable indication when you getting close to minimum voltage.

 

[frazam]

I bought a multimeter and started checking voltages... my AW IMR 18350s come off the charger at 4.1v. No biggie as I read this helps increase the number of cycle times... however, I am concerned with the vape time I get from them. In an hour of moderate vaping (a couple of puffs every 5-10 minutes), voltage drops from 4.1 to 3.7. Is this normal? My UF 18350 lasts longer though it must be because of the higher mah rating. But aren't AW IMRs supposed to put out a higher voltage for longer times? How long does your 18350 batteries last?

Thanks!

 

[Switched]

Rule of thumb conservative = 1hr/100mAh

 

[Bozzlite]

I bought a multimeter and started checking voltages... my AW IMR 18350s come off the charger at 4.1v. No biggie as I read this helps increase the number of cycle times... however, I am concerned with the vape time I get from them. In an hour of moderate vaping (a couple of puffs every 5-10 minutes), voltage drops from 4.1 to 3.7. Is this normal? My UF 18350 lasts longer though it must be because of the higher mah rating. But aren't AW IMRs supposed to put out a higher voltage for longer times? How long does your 18350 batteries last?



Thanks!

If you are taking a couple of puffs every 5 minutes, that's only 24 puffs in an hour. At that rate, your battery should last at least 12 hours before the voltage drops to 3.7.

You really shouldn't let the voltage get much lower than that before recharging.

I get pretty good mileage with my Rough Stacks using the AW IMR 18350 and 1.7 ohm cartos, so I would say one hour is not normal. It might be a bad battery, or a bad charger.

Try this. Charge up your Ultrafire battery, measure the voltage, use it for an hour, and measure the voltage again. It should be a barely perceptible amount, say less than 0.1 volts drop. Post the results here. (I'm the curious type, lol)

Btw, what type of PV are you using? Is it variable voltage? Are you using high voltage and low ohm cartos? But even so, you should get way more than an hour out of the battery. My 18350's charge up to 4.17 volts, but that shouldn't make that big of a difference.

Also, how much vaping time do you normally get from the Ultrafires?

 

[Malduk]

Isn't 3,7V its nominal voltage value? Nothing alarming about that voltage.

 

[Switched]

That would be correct

 

[frazam]

Hmmm...must be my PV then. Well, the 510 connector of my PV has a short. Screw a carto or atty too tight, and it overheats like crazy. Also, I use aluminum foil between the battery and spring for a tighter fit (it's a mechanical mod). Can these contribute to the quick voltage drop? I got a touchwood mini and expect it within the week. I will compare battery performance then. BTW, my AW IMRs are just two weeks old, got them brand new. I really hope it's just a case of my PV needing a repair. Batts are hard to find and expensive here in my part of the world...

Note: I don't want to mention my PV as it might cast a negative light on the modder. However, in fairness, I am the one who still uses the PV despite having a short, and the modder offers free lifetime warranty. I am just waiting for my touchwood mini to arrive so I can send it for repair (as mentioned, I am far from the US so sending my PV for repair means it will be gone for a week more or less. The repair will be quick, it's the shipping that will take long.)

 

[zoiDman]

Hi, I use 18350s and I recently purchased a couple of AW IMRs. I read that they should not be used when undercharged (?).

When I use them, I change them after about an hour of moderate vaping for fear of overusing them and causing permanent damage. But of course, this is very inconvenient for me. My question is, how long does a single AW IMR 18350 last typically? If say, I take 2-3 puffs every 5-10 minutes? How do I know when to change them out? I don't want to use them till they're dead of course. Any suggestions on how you guys do it?

Most people agree that Draining these batteries below 3.3 volts is not Recommended.

 

[Bozzlite]

Isn't 3,7V its nominal voltage value? Nothing alarming about that voltage.

A lithium battery is 100% charged at 4.2 volts.

At 4.1 it is 90%
At 4.0 it is 80%

So, by the time it reaches 3.7 volts, it is only 60% or so charged. Maybe less.

Not saying it's alarming, just saying it's time to recharge.

 

[frazam]

What can cause a PV to draw power from a battery more than it should? I've a feeling my PV is causing my batteries to lose charge faster than normal as my batteries are new. All my batteries lose charge faster than normal (from 4.1 to 3.7 in an hour)...

 

[Bozzlite]

My thoughts are that it is the short in the connector. Either it's causing excessive battery drain when you vape, or it is drawing power even when not in use. I am leaning more toward the constant power drain theory.

If possible, put a fully charged battery in the PV and just let it sit for an hour. Then check the battery voltage. It should be the same as it came off the charger.

 

[frazam]

@Bozzlite: should I leave the connection? Or leave at the off position?

I put in a freshly charged battery earlier, then left it for a couple of hours while I waited for juice to soak in the cartomizer (was using my passthrough at the time). I forgot if it was in the off position, though I think it was... anyway, when I used it, it didn't taste like it was fresh off the charger. I checked the voltage when I got home and it was 3.8 - 3.9v, when it should be above 4v correct? I'm thinking the connector is causing a massive power drain, as per what you said.

 

[CraigHB]

I bought a multimeter and started checking voltages... my AW IMR 18350s come off the charger at 4.1v.

How accurate is your meter? A high-end professional meter can have basic accuracy as good as .05%. A cheap meter from Radio Shack or Walmart may have basic accuracy as poor as 1%. At 4.2V, that would be an error as high as .042V. So, if your charger was terminating at 4.2V exactly, your meter could provide an indication as low as 4.16 volts, but possibly even less since meter error also includes a number of counts or digits.

My UF 18350 lasts longer though it must be because of the higher mah rating. But aren't AW IMRs supposed to put out a higher voltage for longer times

Yes, it's purely a matter of charge capacity or mAh. The advantage of the IMR cells is they have higher drain limits which is good for low resistance atomizers with smaller cells and for mods that use a booster with bigger cells. IMR cells also have less voltage sag. For an unregulated mod, that means they deliver higher voltage to the atomizer under load. It's not a huge difference, but enough to see a slight improvement. But, you give up run time for it.

 

[frazam]

I don't mind an inaccurate meter, as long as I have a fair idea what the voltage is so I know when to charge (I don't let my batts fall under 3.7 to be sure).

My problem is that my batts don't last as long as they're supposed to

 

[CraigHB]

You need to take your batts down lower to get the full run time out of them. The protected batts automatically shut off at 2.7 Volts.

As stated before, 3.7V is about 40% charge so you're only discharging your batteries a little over half way.

If your charger is in fact only charging your cells to 4.1V then your charger is out of tolerance. Minimum voltage is 4.15V and even that's a little low for my own acceptance. A low terminal charging voltage means your cells are not being charged fully.

Li-Ions do wear a little slower when discharged and charged more shallowly, but barring any out of tolerance condtions, it's not going to make a huge difference in battery longevity.

 

[Bozzlite]

@Bozzlite: should I leave the connection? Or leave at the off position?

I put in a freshly charged battery earlier, then left it for a couple of hours while I waited for juice to soak in the cartomizer (was using my passthrough at the time). I forgot if it was in the off position, though I think it was... anyway, when I used it, it didn't taste like it was fresh off the charger. I checked the voltage when I got home and it was 3.8 - 3.9v, when it should be above 4v correct? I'm thinking the connector is causing a massive power drain, as per what you said.

If you didn't use it a lot, yeah it should have been above 4.0 volts.

And another possibility (although small) is that the batteries are self discharging at a high rate. You could charge one up and let it sit (not in the PV) for a couple of hours. The voltage should be virtually the same as when it came off the charger.

 

[frazam]

Tried that with my batteries, and they are not discharging at an alarming rate. After letting freshly charged batts sit overnight, they lost only .01v (as per my multimeter).

 

[Bozzlite]

I hope your Touchwood mini comes in soon so you can send this one in for repairs. Call me a nervous Nellie, LOL, but it could turn into a dangerous situation. Lithium battery + short = potential for venting with flame. Or at least, a very hot PV.