Originally Posted by n4zou

The rectifier is located on a terminal board under the switch. It's tiny so you'll need to look close! That’s the smallest bridge diode matrix Radio Shack sells. About the batteries, you must use batteries with solder tabs! If you hit a bump and a battery gets loose the dynamo will pump 500mA and maximum voltage into your LED's. A cheap dynamo may only kick 9 volts into them but a good hub dynamo could produce up to 15 volts quickly burning out your LED's. If you look closely at the photo your see the batteries wrapped in black electrical tape and wires firmly locked down in the white terminal strip. When I build my final version all that ugly stuff will be gone. All you will see is a project box with a switch clamped to the rack. My final version will be this circuit.

The LED drivers will automatically shutdown the LED and disconnect the batteries when the rechargeable batteries are dead. This way I don’t need to worry about manually opening the switch at stops if I've been running on the batteries with too little charging, like needing to stop often in town, climbing a very long and steep hill with the dynamo disengaged, or riding very slowly. Even with dead batteries the lights will start working again as soon as you start moving. Switch S2 in the circuit is for use with hub dynamos and is not required for bottle dynamo's, just disengage the dynamo from the tire when S1 is open, unless you need rapid battery charging.