Flash tests
8 December 2025 10:27 amI have spent the last couple of days running tests on my USB bike lights to try to work out what they will and will not safely do ( Read more... )
So my provisional conclusions, from what I can remember of my test data, are that it should be perfectly safe to cycle for, say, an hour and a half, spend a few hours on various other activities and then cycle home again, provided you don't attempt to switch the lights *off* in the interim :-O Which means having them flashing away in the bottom of your bag in the cinema, say, and hoping it is sufficiently lightproof -- obviously you can't leave the bike parked and drawing attention to itself outside with the lights left on. It is the trauma of starting up on high-beam that seems to flatten a battery that should in theory have hours of continuing power left in it.
Alternatively, it would probably work if you can remember to switch them off briefly every half-hour or so while riding, which seems to contradict the previous result.
( Difference between tests and reality )
So my provisional conclusions, from what I can remember of my test data, are that it should be perfectly safe to cycle for, say, an hour and a half, spend a few hours on various other activities and then cycle home again, provided you don't attempt to switch the lights *off* in the interim :-O Which means having them flashing away in the bottom of your bag in the cinema, say, and hoping it is sufficiently lightproof -- obviously you can't leave the bike parked and drawing attention to itself outside with the lights left on. It is the trauma of starting up on high-beam that seems to flatten a battery that should in theory have hours of continuing power left in it.
Alternatively, it would probably work if you can remember to switch them off briefly every half-hour or so while riding, which seems to contradict the previous result.
( Difference between tests and reality )