USB batteries

[BigdummySteve]

Although I have several decent batteries is there one with pass through charging which doesn’t automatically turn off? I’m using a sinewave beacon which is a light and charger and would like to bury the battery out of the elements with leads attached but I have to root my current ones out and switch them on. Ideally I need one which just sits there taking a charge and ready for action if I need light?

[JoseMcTavish]

I've got one of these which does pass through and will automatically supply when you plug in a device:

https://www.amazon.co.uk/Enerplex-Porta ... B00OZCVO8Q

It may be that you still need to unplug the light at one end to re-initiate it if it times out though. Is this easier than rooting around for the button?

[AlasdairMc]

How much power do you need? I have now found that for rides of a week or less, a battery pack on its own is lighter (and more reliable) than a dynamo/Sinewave/light solution. I got a massive Anker one (c. 20000mAh) which I rarely make a dent in on bikepacking trips.

[whitestone]

As with Alasdair I find that a battery pack is generally sufficient for a few days. The rechargeable batteries in my GPS have a 5000mAh capacity but a day's use doesn't use all of that, probably somewhere in the 3500-4000mAh mark depending on how often I turn on the screen for navigation. With those fully charged and a charged 20,000mAh battery (weighing 350g) then you'll have six to seven day's worth of power.