Portable Device Batteries that stay on...?

A few months ago I bought 4 of the best rated (according to the sites i found) portable device battery rechargers I could find in an attempt to easily power my deployed imps (mainly 003 breakout versions) with a huge external battery, but then realized in testing at home all of them shut off when there is no current draw, which happens because my imp code does deep sleep for about 1-10 minutes or so, depending on my hardware.

Do any imp hobbyists out there buy portable device batteries (usb) which turn on and stay on, regardless of draw? If so, can you mention a model which does this reliably?

Thanks in advance!

I’m not aware of any… kinda annoying. They are all optimized for high current draw during a phone charging session. You may be able to trigger them by waking up (without connecting wifi) for a fraction of a second every minute or so, but that’s also a bit annoying - and still may not draw quite enough power.

Much less robust, but just using 3x AA lithium in a battery holder may work just as well. If you’re sleeping them your power consumption can be minimal.

I was looking at something like this:

Not sure if it ends-up doing the same shut down thing or not. Appears to allow power draw and charge at the same time. Maybe worth a try, or email them with specific questions.

Yeah, that’s not really needed; the imp can run from the LiIon cell directly (ie connect VBAT to the cell output); the boost on this one will just continuously drain the battery, generally at a higher level than a sleeping imp.

If you’re fine working with bare cells, then all you need is a charge controller, with both that and the imp hooked directly to the cell.