Simple circuit to drain a 1.5 volt alkaline battery?

Question

I need a simple circuit to drain a 1.5 volt alkaline battery at a using a current of 50mA.

Answer 1

E = I R, so you just need to run it through a resistance which has a value R = E / I. Note that this resistance should also include the internal resistance of the battery itself.

Answer 2

Athough a resistor may be used to discharge a battery, the constant resistance value will cause the current flow to drop as the voltage of the battery drops.

Instead of a resistor you can make a constant current source with a linear regulator or with a zener diode and a transistor. The current flow will be held constant as the voltage drops. The current source will adjust its resistance to regulate the current.

Answer 3

If you are playing with basic electrics/electronics you (urgently) need to learn Ohm's law.

"jstro" mentioned it, although not by name, in his answer.

Dividing the cell voltage of 1.5 by your desired current (in mA) gives 0.03. Which is 0.03 kilohms, or 30 ohms.


The other correspondent's 256k would result in a current of a little less than 6mA.

Answer 4

the fastest way to drain a battery is to short it.

the safest way is to close it using a low Resistor (256 K OHM)