Current Drawn From single AA 1.2 V NiMH

[Sanyo.Eneloop]

my question is that a bulb is rated 2.4Volt and .5A(500mA)
if i connect 1 AA NiMH cell and i try to glow that bulb will that bulb draw 500mA per hour on 1.2Volts ???????????????

 

[Black Rose]

Re: Current Draw From NiMH

I assume you are talking about an incan bulb and not an LED.

 

[Sanyo.Eneloop]

Re: Current Draw From NiMH

I assume you are talking about an incan bulb and not an LED.

a normal torch DC bulb

 

[Sanyo.Eneloop]

Re: Current Draw From NiMH

i'm waiting for my answer

 

[Bullzeyebill]

Re: Current Draw From NiMH

Well, do not have any 2.4 volt incan bulbs, but I just now undervolted my Streamlight TL3 with 6 volts, and it lit up, pulling 1.1 amps from the two CR123's (used a SF dummy CR123). With 3 CR123's it pulls 1.25 amps.

Your 2.4 volt example bulb is most likely set up to run with two 1.5 volt alkaline cells, and would not function with one 1.2 volt cell, and draw from battery would be minimal, if any. Typically for incans when voltage drops so does current draw from the cell. I was surprised that my TL3 is running fairly bright with two CR123's, and I will take a bounce with lightmeter check soon.

You have no incan lights to work with and no DMM?

Bill

 

[Mr Happy]

Re: Current Draw From NiMH

Your 2.4 volt example bulb is most likely set up to run with two 1.5 volt alkaline cells, and would not function with one 1.2 volt cell, and draw from battery would be minimal, if any. Typically for incans when voltage drops so does current draw from the cell. I was surprised that my TL3 is running fairly bright with two CR123's, and I will take a bounce with lightmeter check soon.

Actually a 2.4 V bulb will light quite brightly with a 1.2 V supply. Not full brightness of course, but visibly lit up. Incandescent bulbs have the property that the filament resistance decreases with lower voltage and increases with higher voltage, so that they try to regulate the current.

Your result with the TL3 is not therefore that surprising. At two thirds of the normal voltage you get more than two thirds of the normal current due to the current regulating behavior.

 

[Sanyo.Eneloop]

Re: Current Draw From NiMH

guys 2.4V bulb is glowing nicely with 1 AA NiMH but i wanna know on single NiMH cell bulb will draw 500mA @1.2V or 250mA @ 1.2V?????????

 

[Jaunedeau]

Re: Current Draw From NiMH

Ohm's law is : V = R x I

2.4V for 0.5A means that the DC resistance of your bulb is 4.8 ohm.

if R was constant, under 1.2V, it would draw 1.2/4.8 = 0.25A, which is 1/4 of the power.

But at this power, the filament will be cooler, and then have a lower DCR, drawing more current. How much it exactly draw will depend on the type of filament, and also on the capacity of you battery to provide such current. So I would say with an NIMH battery and average bulb you can expect it to draw about 0.3-0.4A. This can be mesured easily to have the true value.

One last point is that at 1/2 it's voltage, the light bulb may be very less efficient.

HTH,
John.

 

[Norm]

Re: Current Draw From NiMH

i'm waiting for my answer

Sorry to keep you waiting.

 

[digitor]

Re: Current Draw From NiMH

guys 2.4V bulb is glowing nicely with 1 AA NiMH but i wanna know on single NiMH cell bulb will draw 500mA @1.2V or 250mA @ 1.2V?????????

From your other posts, I see you have a meter - so why don't you measure the current, and let us know how much it draws?

Cheers

 

[Sanyo.Eneloop]

Re: Current Draw From NiMH

From your other posts, I see you have a meter - so why don't you measure the current, and let us know how much it draws?

Cheers

from that digital multimeter i can measure an cell amps which is showing 5.5 A(checked for 2 seconds max!!)
but how can i measure bulb Amps is consuming per second through multimeter??????

on bulb its printed that 2.4V and .5A if i use one cell to lit bulb will that bulb consume .5A or .25A??????????


I'm still not convinced

 

[Norm]

Re: Current Draw From NiMH

f
but how can i measure bulb Amps is consuming per second through multimeter??????

I don't know why you have seconds in there time is irrelevant when measuring the current the lamp draws

Lessons In Electric Circuits -- Volume VI (Experiments) - Chapter 2

For your question the bottom meter can be ignored.
Norm

 

[Sanyo.Eneloop]

I've conducted this test on a 5.4V bulb running it by ENELOOPS

I lit that 5.4V bulb through 2.4V(2x1.2 eneloops) then multimeter showed me .3A(300mA) current drawn by bulb, after that the bulb is on for continuous 6hours and 45min!!! till .95 V


by drawing 300mAH by bulb it means 5mAH per minute and bulb lit for total 405 mins X 5mA =2025mA

and rated capacity capacity of ENELOOP IS 2000mAH !!!

ENELOOP IS GROUNDSHAKING NiMH!!

 

[Mr Happy]

Note that mAh is mA x h.

So 300 mA for 6h45m gives:

300 mA x 6.75 h = 2025 mAh

You arrived at the right answer, but your working was incorrect. The above calculation shows the correct way to do it.

 

[Marduke]

And why not just check the capacity on your C9000??

 

[Burgess]

to Sanyo.Eneloop --


Welcome to CandlePowerForums !


:welcome:




Hey, do you realize . . . .



You and I both have Battery Manufacturers

as our CPF UserNames.






_

 

[Sanyo.Eneloop]

And why not just check the capacity on your C9000??

Dude I'm from INDIA and there is no maha charger and la crosse available in Indian market, but I've told my brother in Canada to buy it and parcel it to me.

 

[Mr Happy]

Dude I'm from INDIA and there is no maha charger and la crosse available in Indian market, but I've told my brother in Canada to buy it and parcel it to me.

There is a Location field in your user profile (see top right corner of posts). It is good to fill it in so people can know what might or might not be available where you are.

 

[LuxLuthor]

Re: Current Draw From NiMH

Sorry to keep you waiting.

Now I owe you a mouthful of coffee on your keyboard.

 

[Nubo]

...by drawing 300mAH by bulb it means 5mAH per minute

No, your bulb was drawing 300mA (300 milli-Amps), not 300mAH (300 milli-Amp Hours).

milli-Amps is a measure of current, and already has a time component. One Amp (1000 mA) is equivalent to a flow of 6.242 × 10^18 electrons per second.

Amp-Hours and milli-Amp-Hours are measures of how long a battery can sustain a particular current draw under certain conditions.