Ozark Trail OT 500L flashlight.

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Just bought an Ozark Trail 500L flashlight. https://www.flickr.com/photos/63373992@N07/14352632803/ I plan to mount it to the front rack with reflector mounts. The light puts out a good beam that does not blind oncoming traffic and has a run time of 38 hours. The 6AA Coleman and the 6AA Dorcy lights use the same battery compartment so I expect they are made by the same company. Rechargable batteries are very tight in this light and the top does not unscrew so you can't poke them through. I believe the lower capacity batteries will fit better and the lower capacity batteries have more charge cycles and slower drain rate when not used. I put out the word on the flashlight forums to try and solve this problem. 4 cell flashlights are the best choice. With 2 or 3 cells there needs to circuitry to boost the voltage to around 3.6 to 3.8 volts this wastes energy. Also most battery chargers will only charge 2 or 4 cells at a time. If you want a really long run time you can use a Rayovac 40 lumen LED that replaces a flange flashlight bulb in a 4D mag light for a run time of around 300 hours.   

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It turns out these flashlights are not true 6 cell lights and I have no reason to assume other 4 cell lights by the same makers are true 4 cell lights. Mine works on 3 cells in either compartment. This is both good and bad. Lights with less than 4 cells use boost regulators which are around 75 percent efficient. Lights with 4 or more cells use buck regulators which are 90 percent efficient and can drain more power from each battery. I did manage to find Vivitar batteries and chargers at frys.com. I have the 2 cell charger which plugs into a USB port and will charge 1 battery at a time. This charger has taken a lot of abuse including being soaked by rain several times. The 4 cell charger will charge 2 or 4 batteries at a time and plugs directly into an outlet. I carry a 1 inch long adapter which allows grounded plugs to be plugged into an outlet without a ground this also helps fit the charger into outlets with weather covers.