I like the USB option purely for convenience and the fact I don’t have to carry spares. On long rides I have a battery charger and cable anyway, but I have never needed it for lights. Just my phone and Wahoo.
I finally settled on a set of lights to carry as lightweight spares for Audax. I went for the MOON METEOR C3 and COMET X LIGHT SET from
Tredz. With a discount code it cost less than £30.00
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