# how do i increase the current draw from a 3v non-rechargeable lithium battery?

hi, ive got some 1/2AA batteries that ide like to use to make some nichrome wire glow, in a really small device. now, using one of these batteries, im able to make my nichrome wire glow with one , but only if there is less than 0.5cm of nichrome. if i use two batteries, and increase the voltage form 3.6v to 7.2v, then the length of wire it can make glow increases to 1.2cm, which is ok, but two batteries take up too much space.

So i want to know, is there anything i can do, to increase the voltage or current of the battery? such as a simple battery drainer or something that would pull its power rapidly and pass it all through the nichrome wire so that it would glow the same as if the voltage was doubled without actually using a second battery?

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6 years ago
YOu've hit the battery's limit.
oldmanbeefjerky (author)  steveastrouk6 years ago
darn, oh well, it still is the best answer ive been able to get!

oldmanbeefjerky (author) 6 years ago
is there a very small simple and cheap circuit i can use to increase the voltage?
i remember once reading about transistors, and that in a circuit,though this can only be done once i think, the transistor can increase he voltage by X1.5

now, with nichrome wire, i have found, that watts doesnt cause the wire to glow, i dont think there even is a rule on how it works.
there needs to be sufficient voltage, and amps.
100v only needs like 10ma to make it glow, but 100ma will never glow if the proprtions are switched.
doubling current in some cases didnt work, but doubling the voltage, despite halfing the current did work!

anyway, could you recomend some kind of circuit which i could use to do this that doesnt require very many parts?
6 years ago
Ye cannae change the laws of physics
rickharris6 years ago
The current drawn is controlled by the resistance of the load.

So lower the resistance of the wire. - Make it shorter or thicker.
oldmanbeefjerky (author)  rickharris6 years ago
i have 40ga wire, protpotionally twice as thick, and it doesnt work the way you explained.
with 40 ga wire i can only get about 3mm to glow.
6 years ago
Then you are already hittng the battery's own discharge limit - its internal resistance.
6 years ago
pick this guys answer. because he is right.
6 years ago
Current is proportionally connected to Voltage and Resistance.

in the form Volts = Current x Resistance

or to turn it round

current = Volts / resistance (Ohms Law)

So Increase the voltage will increase current OR lower resistance will increase current.

A thicker wire Will draw more current - It also however has more mass and therefore required more energy (current ) to make it red hot.

Your question asks how to increase the current draw. If you were to measure it, you have with the thicker wire.
oldmanbeefjerky (author) 6 years ago
i have considerd everything.
i cant possibly use any other batteries to increase the power enough to get the wire red hot, it just isnt possible, i even tried it uisng 10x cr2032 batteries equating to 30v, and it was barely better than the single battery.

now, i have heard one, that a transistor can be used as a voltage amp, is this true?
verence6 years ago
Can you put two nichrome wires parallel? That equivalent of using a thicker wire. You could even try three parallel wires, but at some point the internal resistance of the battery will stop further improvement.
steveastrouk6 years ago
Yeah, use thicker wire, increasing the area by 2 will give you 1/2 the resistance, so you can double the length. This will only work, up to a point, because the battery will limit how much current you can get