Originally Posted by
Maelochs
A thing to consider---I have been told that after about three years Li-Ion batteries start to lose their punch, whether used or not. That's why in future I will shy away from USB-charged lights and look for lights with replaceable batteries, either AA and AAA cells or replacement units from the factory (where I would always run the risk that they would be discontinued.)
For a $30-40.00 dollar tail light you are going to run many times that amount of desposable battery cost through it. I just plug in my cygo lights( front and rear) when I get to work.