Confused About Multimeter

[Bigflyrodder]

Just bought a multimeter and I'm a bit confused. For batteries looks like the options are to set it at 1.5 or 9 volts. 1.5 just pegs all the way over so tried it on the 9 volts hoping that means it will test up to 9 volts rather than meant for 9 volt batteries only.

When I test a battery that has been in a mod for a while it showed like 4.1, a while later 4.0. Put the batteries on my charger about 3 hours ago and they are still not showing fully charged. How is that possible.

I must be doing something wrong or bought the wrong cheap multimeter from Home Depot. Can you help?

 

[MorpheusPA]

9 does test up to 9; on my meter, the setting is 20 (so it'll handle anything from 1.2 V to car batteries and beyond).

For being in a mod for a while, 4.1 V is a reasonable measurement. Lithium batteries charge to around 4.2 volts, but drop quickly to around 3.8 V and drift slowly down from there.

Charging at the top end of the range is also very slow, so it can take fully half the charging time simply to nudge it from 3.8 to 4.2 V. Or your charger may cut off a little low, which isn't a problem (it'll actually extend your battery life considerably). If it's reading over 4.1 V, it's fine. Mine tends to stop at 4.18 and call them fully charged, which is more than close enough.

 

[Bigflyrodder]

Very helpful, thank you! So, I've always recharded off my mechs when I can tell the battery is low due to performance or from my vv/vw when it gives me a low battery reading. What voltage am I watching for to know I need to recharge?

Just started using a Duke mod which runs two 18650s in line. You are supposed to swap their placement halfway through use and then recharge always using as a set pair.

 

[ch2468]

Depending on your build and vape tastes, you'll probably wind up changing the battery when the flavour and vapour decreases. I tend to recharge my batteries when they hit around 3.7v.

A typical battery discharge curve starts at 4.2v, dips a little at first, then flattens out between 4 and ~3.7v, then falls off sharply at the end of its discharge cycle. It should be safe to run a battery down to ~3.0-3.3v though.

 

[Bigflyrodder]

Thank you! The batteries I have in this Duke mod now came off the charger at 4.2 and now show ever so slightly under 4, maybe 3.9. Been vaping on them on and off for about 24 hours so if the reading is correct I'm happy with that.

 

[MorpheusPA]

Thank you! The batteries I have in this Duke mod now came off the charger at 4.2 and now show ever so slightly under 4, maybe 3.9. Been vaping on them on and off for about 24 hours so if the reading is correct I'm happy with that.

That's awesome. I can drain a batt to 3.7 in a few hours, but I have a perpetual ground fog. I'm like a walking Ed Wood movie.

Very helpful, thank you! So, I've always recharded off my mechs when I can tell the battery is low due to performance or from my vv/vw when it gives me a low battery reading. What voltage am I watching for to know I need to recharge?

The general rule is 3.3 or 3.4, which is set safely high. 3.0 is starting to push it, 2.5 is really pushing it (2.5 is pushing it much harder than I'd ever recommend, actually). It's doubtful that you'd find even 3.0 tolerable on a mech mod, it'll produce a lot less vapor and flavor than 3.8 did!

 

[Bigflyrodder]

Got it, anything below 3.0 is bad! I imagine I usually regarge around 3.5 or so but I'm not even sure that is accurate with this meter I bought. I placed an order today for a $10 digital one that either ........ or vapingdealsndiscounts listed sometime last week and I'll see how that one works.

Thanks for all the info, want to be safe but also want to take advange of extended battery life with the dual 18650s in this mod. Still learning.

 

[k702]

hate to hijack the thread, but what should i have my multimeter set to for reading the resistance of my coil? Was pretty sure I knew then I tried and I get really wacky numbers.

my mutimeter vvv

 

[Bigflyrodder]

I would guess 10A at about the 4:00 position? No idea which connections you'd use though and the setting is just a guess, I have no idea really...lol.

 

[havinfun1]

Set dial sraight down to 200

View attachment 316688

Touch leads & subtract this number when you check your coils.
View attachment 316691

The original test leads that came with my meter were reading something like 2.3 ohms, I made up these leads with 14g silicon wire to get the ohms down so it was easier to work with.

 

[PaulBHC]

Thanks havinfun1. I have a similar tester and got high numbers compared to my MVP which seemed closer to advertised.

 

[edyle]

Got it, anything below 3.0 is bad! I imagine I usually regarge around 3.5 or so but I'm not even sure that is accurate with this meter I bought. I placed an order today for a $10 digital one that either ........ or vapingdealsndiscounts listed sometime last week and I'll see how that one works.

Thanks for all the info, want to be safe but also want to take advange of extended battery life with the dual 18650s in this mod. Still learning.

What specific kind of batteries are they?

For me, I wouldn't risk stacking batteries; worse yet 650's.

 

[leerm8680]

Here's a great multimeter tutorial

http://learn.adafruit.com/multimeters

 

[k702]

Set dial sraight down to 200

View attachment 316688

Touch leads & subtract this number when you check your coils.
View attachment 316691

The original test leads that came with my meter were reading something like 2.3 ohms, I made up these leads with 14g silicon wire to get the ohms down so it was easier to work with.

Thank you!

 

[Bigflyrodder]

Update: Just got my $10 digital multimeter on sale at Vaporkings (thank you very much).

Pulled a battery out of mod and tested on the analog multimeter I bought at HD this past weekend and close as I can tell reads 4.0, maybe 3.9. Put it on the new digital and it reads 3.71 which I think is much more accurate and soooo much easier to read. Winning!

Thanks so much for all the advice!

 

[Vaya]

I've begun to try my luck at rebuilding tanks, having gotten an Atomic and a Patriot. I neglected to get a multimeter, because both my SVD and my VTR have the capacity to read ohms on them. However, I do not want to inadvertently damage either the device or the expensive RBAs - are the aforementioned APVs sufficient and trustworthy means of ensuring this goal, rather than purchasing something like the OP in this thread has? I've decided not to touch the RBAs until I have all the equipment, but if I an reasonably avoid spending $30 on a multimeter, or even an ohm checker, I'd like to opt for that...

 

[k702]

I've begun to try my luck at rebuilding tanks, having gotten an Atomic and a Patriot. I neglected to get a multimeter, because both my SVD and my VTR have the capacity to read ohms on them. However, I do not want to inadvertently damage either the device or the expensive RBAs - are the aforementioned APVs sufficient and trustworthy means of ensuring this goal, rather than purchasing something like the OP in this thread has? I've decided not to touch the RBAs until I have all the equipment, but if I an reasonably avoid spending $30 on a multimeter, or even an ohm checker, I'd like to opt for that...

you can get a good multimeter for 10 bucks. Or an ohm meter for the same price. or both for less than the 30 you mentioned.

I got my multimeter for free from harbor freight. they run ads all the time for them.

 

[dripdaze]

Yeah go for a free one. That's even better than a $5 one. They are only for your safety any way. Why would anyone want anything more than the cheapest junk that can be found Jeez!

 

[edyle]

Multimeters aren't that expensive,

If you get a rebuildable, a good use for a multimeter is for just measuring the ohms per inch of whatever wire you are about to use.

 

[Bigflyrodder]

For the record I use an ohm meter while building, I bought the multimeter so I could check batteries not for checking my coils.