There are some impressive voltage converters there, at amazing prices… However I didn’t see anything adjustable, to get 5.25 or so. There is a 6V one so one could get 5.25 with a low dropout stepdown regulator after it, with a minimal power dissipation.
I did actually manage to get the Lenovo T2 tablet to work adequately from my existing 5.00V power supply, by re-wiring the lead with a thick wire and as short as I could get away with. It doesn’t actually charge during flight, with the screen on, but it doesn’t discharge which is perfectly good enough.
Nowadays TrueBluePower makes
https://www.truebluepowerusa.com/products/aviation/voltage-converters/tc120-series/
https://www.truebluepowerusa.com/products/aviation/voltage-converters/tc240-series/
that are adjustable from 5V to 18V, as well as USB power ports with USB-PD support that will output up to 2×60W at 5, 9, 15 or 20 V (depending on the USB-PD negotiation).
https://www.truebluepowerusa.com/products/aviation/usb-charging-ports/ta360/
They ain’t cheap.
Thanks Those are quite heavy duty and impressively built boxes.
I eventually got around this 5.25V requirement by building my own 5.25V power unit. However, I used the Lenovo tablet from 2013 until 2019 and then went “backwards” to a Samsung T705 8" tablet which doesn’t have this stupid issue, and does everything needed including acting as a backup phone for my phone, runs all the VFR charts, runs EasyVFR, and unlike the Lenovo tablet it never shuts down because it uses a slow CPU
The Lenovo win8 tablet was absolutely needed only to run the Thuraya XT satphone, which had winXP and win8 USB drivers, but that phone got obsoleted by the much better Golze ADL150 system which is neat and just keeps working.
https://charge4.harkwood.co.uk/
Have one of these with which I have been very pleased.
Profiles can be loaded for specific devices as required.