Portable Power - in a rechargeable format
I am not so sure why it took me so long to come to a portable power solution. I now have two power packs to provide me with 12V and 8V. I have built these power packs to use 18650 cells. These cells can be easily recharged with an XTAR (cheap) charger. I 3D print the packs and used salvaged battery connectors. With a bit of soldering and hot glue, I now have two more options for power. (finally!)
When I started building robots, I used rechargeable power banks. These worked very well, but were limited to just 5V. I had a second bigger power bank that provided 5V and 12V, but it is quiet heavy. I wanted to have more options, but I did not want to invest in expensive hobby LiPos and chargers - although they look extremely tempting.
A local Maker recommended the XTAR charger and over the counter 18650 (used by all the Vapors!). I just need to have some packs for them. Finally, over this Christmas break I have invested the time and made my packs. They could be A LOT nicer - My craftsmanship has waned a bit more than I realized! ;)