Looking for threads

[Skyfntm]

Hey guys I have been looking for some threads here on ecf that I have forgotten to bookmark.

if you guys don't mind helping me out and post the links here for me I will appreciate it.

First thing ink is I'm looking for the formulas to determine amp limit/draw.

Also the formula to determine the minimum ohms a battery can handle.

Thanks for for taking a look.

Skyler

 

[DKP#]

Ohms law:
V=IR
P=IV

V=volts
I=Amps (current)
R=Ohms (resistance)
P=Watts (power)

Amp limit comes from battery specs. Stay well below the stated value. There's a formula to get the max current from the mAh rating but I'm unfamiliar with it.

Minimum ohms:
Voltage: A fully charged battery is 4.2 Volts. Use this instead of the "nominal" voltage of 3.7V
Current: use no more than 80% of a stated max value. 50% would be better since it's right up to your face.

so, if you have a battery with a max current of 10 Amps...
V=4.2V (full charge)
I=5A (large safety margin)
Ohms law: V=IR
Ohms law rearranged: R=V/I
R = V/I = 4.2V/5A = .84 ohms minimum

Whats the power?
P=IV
Voltage: here, use the "nominal" 3.7 volts, it will be closer to the average voltage
Current(I): I = V/R = 3.7/.84 = 4.4A
P = IE = 3.7V x 4.4A = 16.28 Watts

 

[Skyfntm]

Thanks DKP#. Now just need the formula to get the amps.

 

[generic mutant]

It depends on the specifics of the battery.

Multiply the 'c rating' by the capacity in mAh for the maximum continuous discharge rate in mA, divide by 1000 for amps. You'll probably want to stay well below that for a 'safety factor' anyway.

Some good info here:

http://www.e-cigarette-forum.com/fo...-discussion-safety-battery-info-warnings.html

 

[Rickajho]

Thanks DKP#. Now just need the formula to get the amps.

As DKP# already stated AMP ratings are a manufacturer's specification. Was this the list of battery ratings you were looking for?
http://www.e-cigarette-forum.com/forum/blogs/baditude/4848-9-battery-basics-mods-imr-protected.html

 

[thatguy2]

Simple as PIE, uh-huh.. let's see P=I*E/.. Make another pot of coffee..
Download and Install --> eJuice Me Up - Best eJuice Calculator
Select "TOOLS"
Select "PV TUNE"
Enter any 2 knowns (voltage, amperage, wattage or resistence)
Select "CALCULATE"

Sip coffee as you enjoy the answers..

 

[Skyfntm]

Generic mutant got it. Thanks all for the information.

 

[Thrasher]

Ohm's Law Calculator


https://www.commonsenserc.com/page.php?page=c_ratings_explained.html