Led Lantern

I tried plugging in an adapter 6 volts of power in it and it works fine. I also tried using 3 Volt and got the same brightness level. The main point is does it affect the useful life of LEDs in these circumstances? I am currently considering the series connection of another lantern to dilute the tension, but I just want to know if the LED is still the best work on the voltage up or down.

A simple LED circuit comprises a power source (battery), the LED and a certain type of current limiting device (such as resistance or internal resistance of the battery).

A single red LED usually falls between 1.7 to 2.2 V 20mA. A single white LED usually falls between 3.1-3.8V at 20mA.

The data sheet shows that the intensity of the LED varies almost linearly with the amount of current through the device. So, as changes in battery voltage with a "simple" circuit LED intensity will definitely change. Some LED flashlights use more resistance in series with a common and a higher voltage battery. They are still "Simple" circuits. The resistor controls the amount of current flowing through the LED. Much power is lost in the current limiting resistor, which reduces efficiency and battery life.

More expensive, more tech flashlights use electronic type switching regulators. These devices are much more efficient and can apply the same output current over a wide range of input voltages, so what you find with batteries to light precise ... even when the battery is low and the voltage drops. Therefore light is the same brightness over a range of input voltage.

These switching regulators excellent work when the battery voltage is low. But these circuits are assigned to a maximum input voltage. Exceed the voltage and you can permanently destroy the circuit .. and light.

I would like to avoid exceeding the recommended batteries or AC adapter voltage above 15%. This would improve your chances of destroying the light.

it depended on the circuit board, if it is constant current design of protection, then it can handle 6 volts, otherwise the tension will be strong in the short life of LEDs.
To ensure the security light, 3 Volts is recommended. Lanter or 2 in series is better than Lanter powered by 6 volts. Or you can use to share a resistance voltage, 4.5 volts will not Lanter, but the resistance of certain wastes power.

An LED is a diode (Light Emitting Diode) and the diodes are on or off. Nothing in between. Thus, brightness is not affected by more (or less) voltage. No more than the amount of tension affect the "useful life" of the LED.

What affects one LED is the amount of current that could burn the LED, then there is probably a current limiter in the lantern to prevent such damage.

Yes, but I would use for 4.5V regulators, probably with a switching regulator for better efficiency.