I know it’s been a while since this question was asked, and I’ve been following the answers since the recall was first announced. I’ve since replaced my Big Blue with an Aiwa Exos 9, and while it’s a nice replacement, the Big Blue is so much easier to grab and take somewhere.
This evening, I decided to take a closer look and played around with the speaker a bit. Turns out, while the Lithium Ion battery pack is ~11 volts, the charger input is 18 volts… which just so happens to be the voltage of many cordless tool batteries. Sure enough, I’m currently powering my Big Blue off of my Makita LXT batteries through a cobbled together adapter - with the internal battery removed. It’s not the most ideal solution, but it means I get my speaker back to full portability without worry of fire.
I hope this idea helps other people regain their speakers!