IM SO CONFUSED

aaron_cg · Sep 1, 2009

I need to figure out how long these batteries will last with this bulb. I have a race this Saturday.

Here is a link to the battery info: http://data.energizer.com/pdfs/123_ap.pdf

And Here is the info on the bulb Ill be using.

Radio-Shack
Rated Voltage- 6.0V
Rated Current- 650mA
Lamp Type- KPR112
Brightness- 5.46MSCP

Thanks for any info you can provide.

Capo_au · Sep 2, 2009

The cell is 3v with a capacity of 1500 mAh (to 2.0 volts).

Your globe is 6v with a current of 650mA.

So you want to work out the power used by the globe first off.

Thats: 6Volt * .650Amp = 3.9Watts

The cell in watt hours has: 3volts * 1.5Amp Hour = 4.5Wh.

So in short, a rough estimation would be around an hour or so with more or less full brightness then it will quickly get dimmer for the next 30min or so to a point where its no longer usable.

Hope thats some help.

Edit: Just out of interest, what are you racing and whats the light your using?

Burgess · Sep 2, 2009

to Aaron --

Does yer' light use just 1 battery at a time ?

Or 2 cells at once ?

Oh, by the way . . . .

:welcome:

_

Mr Happy · Sep 2, 2009

Burgess said:
to Aaron --

Does yer' light use just 1 battery at a time ?

Or 2 cells at once ?

...or even three cells at once? The battery produces about 2.5 V under a decent load, so two will be 5 V. With a 6 V bulb it won't be all that bright. On the other hand three will be 7.5 V. The bulb is going to be over driven and shining like a star, if it doesn't go poof :poof: first.

On the whole I think we are more confused than Aaron. More information would be helpful.

old4570 · Sep 2, 2009

My guess two batts , so your looking at run time ..

If the batt is true 1500mAh and current draw is true 650mAh

You will see over 2 hours , but depending on many things , light output will start to drop at a certain point . Easiest thing to do is load up and go for a ride to see when it becomes less than acceptable .