Q: Can I just use regular alkaline batteries so I don't have to mess with recharging batteries when I need them?

A: Yes, in certain applications like the SMJLED bi-pin bulb for AA flashlights where the flashlight does not use a DC/DC converter, Energizer lithium AA or alkaline batteries can be used for best performance. However, in applications that use a DC/DC converter we recommend against their use, except in emergency situations for the following reasons:

First, although alkaline cells may have a larger rated energy capacity (18000mAh alkaline D cell vs. 10000mAh NiMh D cell) when used in high current applications such as portable lighting, they can not deliver as much energy as NiMh cells. Alkaline cells can not maintain high currents for extended time periods like NiMh cells can, and may leak if over discharged.

Second, rechargeable batteries not only save you money, they also reduce the waste going into landfills which helps save the environment. NiMh rechargeable cells can be recharged up to 1000 times. So over the life of a rechargeable NiMh D cell, it can eliminate 1000 alkaline D cells going into the trash (over 250 lbs of toxic waste) and can save you $1000.00 based on an alkaline D cell price of $1.00.

Third, since NiMh cells do not have the charge 'memory' problems of earlier NiCd cell technology, they can be recharged to full capacity at any time. This means you can always start out with fully charged batteries providing a known run time, unlike alkaline cells which leave you guessing how much energy is left in the batteries since the last use. Also, with modern computer controlled chargers, the NiMh cells can be left in the charger under trickle charge so they are fully charged and ready to go when needed.

Q: What is a DC/DC converter?

A: A DC/DC converter is circuit that will change DC voltage from one voltage level to another. Converters are used in LED flashlights because in many instances the batteries don't produce the correct voltage to properly light up the LED. 

For example, a 3 watt Luxeon LED typically needs 3.9V to reach full brightness. Two NiMh D cells only produce 2.4 volts. So a DC/DC converter is used to change the voltage from 2.4 Volts into the 3.9 Volts required by the LED. DC/DC converters also typically regulate the voltage and current supplied to the LED resulting in a more constant level of light output during discharge of the batteries.


Q: Can the modified flashlight be returned to its original stock form if desired?

A: While technically possible with a little work, nobody has ever asked to have the "dim yellow light beam" restored to their flashlight. 

Q: What is the difference between Lumens and Lux?

A: Lumens is a measure of how much light is produced, and Lux is the measure of how bright the light is at a specific distance, usually one meter. Lumens are measured in specialized devices called Integrating Spheres that internally reflect all light back to a sensor to measure the quantity of light produced. Lux are measured with a light meter placed one meter from the light source and measures the intensity of the light at that distance. 

For example, an ordinary 60 watt light bulb lights up a room better than a flashlight (because the 60 watt bulb produces more Lumens), but the flashlight can project a brighter spot of light on a distant wall (because it produces more Lux) than the 60 watt light bulb.