Flashlight Project: need some help please.

[jason303]

Just as you would measure voltage at the terminals for a household dry cell battery, such as a 9-volt or AA 1.5 volt battery, you would measure voltage from your cell phone battery likewise. Leave the flashlight on a while and the voltage will slowly go down. If cranking the handle raises the voltage on the battery, then your setup is working. From what I can see on your photos, you set your voltmeter to AC voltage. Use a DC voltage setting instead. AC comes out of your house electrical outlets; DC comes out of batteries.

Note for all: Use your voltmeter (set to DC volt) to test batteries after your flashlight, kid's toy, whatever dies. If the battery voltage is less than 85% of what it should be, replace it. Often an gadget that takes four batteries will fail after only 1 or 2 batteries lose their charge. Don't throw out the two good ones!

[Irving]

Thanks for the tip on the voltmeter, I tried both settings, but used the AC setting for the picture I took. I'll have to fix my voltmeter and try it again.

I noticed that if I put the leads on the button battery, the needle would slowly, but very visibly, go down the whole time I held it on there. When I held the leads to the cell battery for a long time, the needle never moved. Also, I've been messing with this flashlight all day long and none of the readings have changed at all, no matter what I've done.

[jason303]

I noticed that if I put the leads on the button battery, the needle would slowly, but very visibly, go down the whole time I held it on there. When I held the leads to the cell battery for a long time, the needle never moved. Also, I've been messing with this flashlight all day long and none of the readings have changed at all, no matter what I've done.

My guess is that those little button batteries have a very small fraction of the capacity as the cell phone battery so it'll take alot of flashlight shining to drop the voltage of the cell battery. If that is the case it would take a lot of cranking to charge it back up. Attach a windmill to the crank and get some stimulus money.

[Irving]

So I hooked everything up like you suggested Jerry, and I got the needle to move, but only on the 0.5 mAh setting. The needle seemed like it was trying to all the way left, instead of going to the right like it does on a usual measurement. The needle would not budge on the 50 mAh or 250 mAh settings. What does this mean?

[jason303]

So I hooked everything up like you suggested Jerry, and I got the needle to move, but only on the 0.5 mAh setting. The needle seemed like it was trying to all the way left, instead of going to the right like it does on a usual measurement. The needle would not budge on the 50 mAh or 250 mAh settings. What does this mean?

Instead of going to the right means you should reverse polarity (switch + & -) and won't budge on the 50 & 250 mA scales means your light bulbs aren't pulling enough current to even register on your meter. Stick to the 0.5 scale.

[jerrymrc]

So I hooked everything up like you suggested Jerry, and I got the needle to move, but only on the 0.5 mAh setting. The needle seemed like it was trying to all the way left, instead of going to the right like it does on a usual measurement. The needle would not budge on the 50 mAh or 250 mAh settings. What does this mean?

Something is not right. It should move to the right. Unhook both wires from the generator and test the polarity of it making sure to reset your meter to read volts.

[Irving]

Hmmm, the thing with the generator is that I never touched those wires. All I did was solder a wire between the (+) tab on the original battery terminal, to the (+) on the battery, same thing for the (-).

If you look at the first and second picture, you can see that the White (+) and Black (-) wires go from the cell battery (far right) to the original battery terminals on the circuit board on the far left. The White and Black wires go around the generator, then under the on/off switch. The small red and black wires go from the generator (round thing in the middle), to the circuit board on the left. The larger red wires go from the switch to the board.

[kwando]

those windups are a joke... stock! thats cool that you are attempting to mod it.

go with a cree lamp, they are great!

check http://www.candlepowerforums.com/vb/