anyone know a way of testing the voltage on the batteries?

[BurningChrome]

if you reverse the black and red leads you will get a negitive voltage - no need to switch the probes just take the absolute value of the reading. On the multimeter the probe inputs are usually color coded, but it really doesn't matter. The probes are exactly the same except for color (Colour).

[BurningChrome]

guess I am too slow.

[dc2k08]

thanks GTO got it. got a reading of 4.09 on the battery..my problem was i was switching the red probe to hole 1 to test volts. i thought hole 2 was explicitly for ohm reading. cool now i will be able to test all the batts and see which ones are best for quality.

i dont suppose you can test a battery's MUH with this device?
also GTO, why do you suppose some batteries give up? are there different reasons? anyway of shocking life back into them with the multi-meter?

also thanks for the input BC.

[GTOrichie]

batteries tend to get old you can cycle them on the charger a few times without discharging them to try and bring there "Memory" back up but they tend to drop off over time, Lithium are normaly very good cells, I use them often in Rc models and electronic projects, but I guess these are cheep cells and are prone to damage from the abuse e-smoking gives them.
When you say MUH do you mean mAh?

[dc2k08]

yeah, i guess i must mean mah. the amount of power a battery can contain as i understand enabling it to last longer on a charge.

sometimes batteries come not working, and sometimes refuse to work after a week. i dropped one it its head once and that did it. it would stay on sporadically causing the atmzr to sizzle or it wouldnt work at all. this happened also to another battery that hadnt been dropped. you think the micro-chip is to fault or wiring?

[GTOrichie]

if the battery is intermitant it's more likely to be loose wires or loose components(known as dry joints), if you know how to strip the unit it may be worth having a look to see if it can be soldered.

the mAh(milliampere-hour) is the runtime of the battery, if you think of a fuel tank the more it holds the higher the no. of ltrs well its the same with mAh on a battery. to test your batterys mAh you can use ohms law(I=V/R) to get a rough idea, you know the volts of the battery and you know the resistance of the atomizer so if you take the volts and divide it by the ohms you get the amps of the circuit. now time how long it takes for your battery to die (only the time the switch is engaged) so say your avarage drag is 4 seconds see how many drags it takes to die and work it from there. so for arguments sake the Amps of the circuit are 1A and takes 1hour for the battery to die you know that the battery is giving you 1 amp hour 1Ah or 1000mAh (1000ma = 1A) if it gives you 1.5 hours you know you are getting 1.5 amp hour or 1500mAh and so on

I hope that makes sense but I find it hard to put it in writing (dyslexia), hence all the spelling mistakes, I am almost sure I haven't made any factual mistakes but if anyone spots any let me know (i would have never made a good teacher lol)

[dc2k08]

your making perfect sense GTO, i really appreciate it..so say now, i have here an atomizer of 3.6 ohms, and a battery readig 4.09v..

so i divide 4.09V by 3.6 ohms...i get 1.14 amps (I stands for amps in the eqaution?)

say i find out the battery lasts for 1 and half hours..

i multiply 1.5 (the time) by 1.14 (amps) which = 1.71 amps/hour or 1710 milli-amps/hour? (1710mah)
is that correct?

or do i divide 1.14(amps) by 1.5(time) and then multiply by 1000 to find the mah, giving me 760?

[clavit]

You're spot on DC, in your example 1710 mah is the correct one!
By the way i just measured 3.68volts on a batteri that gave me the "time is up"-blink.
If these Lithium batteries have a nominal voltage of 3.7volts, that doesn't allow for much of a voltage drop before the warning light goes off.
Does anyone know if this is normal behavior with lithium batteries? I seem to remember that with nicd and nimh bateries, battery voltage could be taken as indication of the level of charge (and general health) of the battery.
GTO? Anyone?

[dc2k08]

1710 seems high. i imagine im way off with the 1.5 hour. its probably more like .5 of an hour or less, if you add it all up. im saying that cause someone quoted me once that an e-cig battery had 330mah...thats like 15-20 minutes use at those volts and ohms.

so T(time) x A(v/ohms) x 1000 =mah

also
T = mah / A x 1000

so if i knew the amp and the Mah. i could predict how long a battery will last...perfect!

[GTOrichie]

when a battery is first charged it will read higher than its standard rate(chargers are very ineffiant) and when its dead it will read lower than its standard rate, this is a common factor shared with the type of batterys you will use NiMH, NiCd, Li-ion and Alkaline alike, Li-ion are used in alot of modern aplications due to there high rate of power to lower weight ratio,
modern radio controled flight being a prime example.
I have been using Li-ion for a number of years in my Rc cars and aircraft for better power to weight ratios and have found expensive cells to way out perform budjet cells when they have had a bit of use. the charger is a vital part of the perfect recipe that is often overlooked a good charger peak charger will always make your batteries last longer than a bad one but I don't know if my normal Li-ion peek charger will work in the case of the E-cig battery with the chip it has inside (I will strip one when I have one that gets lazzy or dies and check out how it works)

there are alot of good Li-ion battries avalible in the Radio Controled world of all sizes and power so if you do get a bed unit it may be worth striping it and changing the cell for a quality one(I bet you would be suprised by its performance)