Light Weight portable setup for Karaoke no electrical outlet

I don't drive anymore, but I am a bicyclist. I want to be able to cycle out on the bike trails and practice singing. I have a small cargo trailer, but going uphill can be problematic with a lot of weight. I already have a laptop and tablet which I can bluetooth to my I-Phone as a hotspot. What I need is a decent sound interface that can operate off my laptop USB power and a speaker/monitor that is rechargeable, and decent volume without being extreamly heavy. I want a speaker that has a mic jack and a few sound effects etc... for when my laptop battery is dead and I can just use the tablet to Bluetooth to it. That way I can connect threw laptop/music interface OR just threw tablet.