From the advert:
Working Time 4 hours (Built-in Li-ion battery, charging and discharging protection, constant current work.)
I'd expect that to be for the small one, as the laws of physics dictate that the larger ones will discharge the battery faster.
And again, from the advert:
Built-in 4400mAh Li-ion battery support working time up to 6 hours.
Very reasonable size in my book.
From another seller Less choice, but keen price on the 20w.
Gary, wish I'd had your gig, that list's not particularly exciting, but I'd have been singing all of them. Nice.
OK, my review.
Like Gary, my venue was hot, very hot. 70th Birthday with a predominantly older mixed age group. I couldn't find anything to populate the floor reliably, and ended up all over the place. There was no forecasting the floorfillers, eg Wonderwall packed the floor, and a lady my sort of age asked for Sex on Fire, which also worked well, and led into a couple more in the same vein. Abba was well received, as was Elvis.
My, but it was hard work. :( Dancers were understandably reluctant in the heat, and no style of music stood out as the one to play. By the last song of the night, I'd actually run out of ideas totally, and had to fall back on NYNY for the final one. Just before that, the client asked for the mic to thank the guests for coming, and also me for doing a good job, which was nice.
Didn't feel like a rewarding night, and the journey home fighting the sat nav didn't help. There are three routes for this one, the long motorway one, the short one, and a middle one. Sat nav wanted to go on the motorway, and when I missed a turn on the short one, it became a battle of wills. Think I lost on points.