I don't think I've seen these mentioned on here:
https://www.amazon.com/gp/product/B074FHLC2F/
I bought one to make my dot portable and it works really well. Sometimes you can find them on sale for less than $38.
If I had it to do over again, as much as I like my Tap, I would just buy a Dot and upgrade it with a Mokcao Power or similar option for portability. My Dot sounds better with this upgrade than my Tap. The only downside is the Tap probably gets a couple more hours on the battery. But since the Tap is not getting the upgrades the Dot has been getting feature-wise from Amazon I would not buy another Tap.