Is there a low voltage led light that will last a long time?

A 1.5 volt AA battery has a lot more current capacity than a 9 volt battery (1800-2600 mAh versus 565 mAh). But the led needs around 2.1 volts to light, and 3 volts for a white led, so you could use the circuit below (source 3) to step up the voltage. You could use source 4 with 2ea. 1.5 volt batteries in a holder from Radioshack to turn the light on only when dark.

a single red LED takes about 2.1 volts at .018 amps so you need to find out how many amp hours you battery can produce. A better solution is to use a garden path light. -- use the solar panel from it to keep some batteries charged. If you can get sunlight to the panel during the day to recharge the batterys then you can get many years from the battery. You can use several path lights (walklights) wired in parallel to run one red led. A red LED will use less power than the white LED's that come with the walklight so you will get more lighted time out of them.

yes. Oh, you want to know how. A forward biased led light at vary low current can last a long time on a battery. You can calculate how long to expect by looking at the Ah rating of a battery and dividing it by the current of a led circuit that is about the right light level for you. As you may know, increase the resistor's value that is in series with the battery and led until it is the right light level. Measure the current with a VOM and use this value in the calculation. I hope this helps.

A 1.5 volt AA battery has a lot more current capacity than a 9 volt battery (1800-2600 mAh versus 565 mAh). But the led needs around 2.1 volts to light, and 3 volts for a white led, so you could use the circuit below (source 3) to step up the voltage. You could use source 4 with 2ea. 1.5 volt batteries in a holder from Radioshack to turn the light on only when dark.

yes. Oh, you want to know how. A forward biased led light at vary low current can last a long time on a battery. You can calculate how long to expect by looking at the Ah rating of a battery and dividing it by the current of a led circuit that is about the right light level for you. As you may know, increase the resistor's value that is in series with the battery and led until it is the right light level. Measure the current with a VOM and use this value in the calculation. I hope this helps.

a single red LED takes about 2.1 volts at .018 amps so you need to find out how many amp hours you battery can produce. A better solution is to use a garden path light. -- use the solar panel from it to keep some batteries charged. If you can get sunlight to the panel during the day to recharge the batterys then you can get many years from the battery. You can use several path lights (walklights) wired in parallel to run one red led. A red LED will use less power than the white LED's that come with the walklight so you will get more lighted time out of them.

Indestructible Tactical LED Flashlight : http://FlashLight.uzaev.com/?DNuH

Check your local hardware store. There are dozens of different products out there.