Power through adaptors for Android tablet?

I’ve installed Cubasis 3 on my android tablet and tried irig with it which works well but the downside is the battery life.
I just tried using it via a cheap otg splitter cable hoping I could get it to run whilst the pad was ‘powered’ or charging. It doesn’t work with this splitter but has anyone managed to find one that does work. I’m never that far away from a power point but have an assortement of powerbanks chargeable and solar I could use if I can get a ‘power through’ device that will work.
Any ideas?