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Would placing a resistor in a circuit be an easy way to aid in draining the battery?

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RDagger

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Hello.

I have a kinda stupid question pertaining to resistors and their use in circuits. I have basically nil electronics knowledge, and am only a high school student at the momment.

What I decided to do for an experiment was test the effiency of different PP3 batteries. I planned to do this by making a simple circuit. A flashlight bulb, the battery and a resistor to decrease the life of the battery.

What I was wondering was what sort of resistor would I need to do this?

Like I said, I really have no idea here.

Would placing the resistor in the circuit be an easy way to aid in draining the battery?

Thanks.
 

Re: Resistor question.

In a practical way:The resistor is a component which resists the flow of current.
It is like the tap of water if you open the tap no resistance water will flow with higher intensity. When you close the tap (resisting the flow) less water will pass.
Therefore if you add resistors it will resist the flow of current.
 

Re: Resistor question.

Correct thought but please be more specific about PP3 batteries. What is the Ah of these specific batteries?( there is an indication on the battery for it).


As you want to make it as a demonstration, you should better use a bulb or a resistor in series with the bulb and count in how many minutes/hours the bulb will sto lighting. Then you can verify the outcome with the battery indication of Ah.

D.
 

Re: Resistor question.

I'm not sure where abouts on the battery the Ah is. On the battery I have in front of me the only writings on it are 'No. 1222 6f22'

And I was hoping to just measure the time taken to drain each battery, but not to compare it to the Ah.

Thanks.
 

Resistor question.

Keeping the resistor in the circuit wil decrease the draining of the battery.. It resists the flow of current.. Larger the resistance,larger wil be the time taken for the battery to drain..

If u directly short the 2 terminals of the battery(Equivalent to say connecting a 0 valued resistor),it drains with minimum time..

Hence it depends largely on your application.. If u want the battery to drain slowly,use large resistance..
 

Re: Resistor question.

So I understood also.

Look now: Ah is Ampere x Hour which gives you exactly what do you want and it is used as the effectiveness of the battery. Ampere is the unit for the current and hour is the unit for the time.

Now follow these simple current laws ( as Ampere indicated):

Voltage of battery = Current from batteru x Resistor ( V=I x R )

Now if you put a resistor of say 1k Ω and the voltage of the battery is 1.5V then then the current flowing through it will be I = V / R==> I = 1.5V / 1kΩ ==>I = 1.5 mA

So, if your battery drains in 1 h then the efficiacency will be 0.015 Ah.


In order to ensure that you are timing correctly, just put a bulb in series with the resistor. Add the bulb resistor to the resistor you have ( measure the two points of the bulb or find it out: if the bulb is a 1W working at 1.5V then P=VxI==>P=V²/ R.
Solving the equation youwill find the bulb resistance. So your new resistance will be Rt=R+Rb.

Did it help?

D.
 

Re: Resistor question.

Yeah, that helped.

So, the higher value resistor will mean the battery lasts longer..?

What can I put in the circuit to drain the battery quickly?
 

Resistor question.

To drain the battery quickly,just short it with a wire.. Since wire has very little resistance(Usually in the order of 0.3 ohms) it wil drain the battery at once.. But its largely not advisable to short the battery as it wil damage the battery due to sudden flow of charges which heats the battery up to a great extent.. So use resistance of order of some 10 or 100 ohmn..
 

Re: Resistor question.

Wait, let me rephrase.

If I had the battery connected to a flash light bulb, what could I place in the circuit to help drain the battery, without just getting a bigger bulb?
 

Resistor question.

Directly connect the battery and the bulb to get the best result in terms of power delivery to the bulb.. But its better to use a resistor of some 100 ohms in series to the bulb to help the battery drain a bit slower without damaging the bulb and the battery itself..
 

Resistor question.

So there's no electronic component I can put in the circuit to aid in draining the battery faster?
 

Re: Resistor question.

RDagger said:
So there's no electronic component I can put in the circuit to aid in draining the battery faster?

If u want to drain the battery dont use any components at all.. Electronic components can be used to control the flow of current in the circuit.. Components like transistors,diodes help to control the flow..

But they dont help in draining the battery faster as shorting the 2 terminals is the best way to drain the batter faster.. If we use any other components in the middle,then it wil lead to increase in resistance which will again resist the flow of current..
 

Resistor question.

Hm..okay..

Well, what about adding more 12 watt bulbs in parralel? Wouldn't this drain the battery faster? I need to drain the battery in a measurable amount of time..
 

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