I have a very old KB60 who still does a great job 30 years later.
the new line seems interesting : https://peavey.com/products/keyboard-amplifiers.cfm

With a battery operated keyboard amplifier you will have to keep your expectations in check. Keyboards (especially the left hand) can be very taxing on a power supply. Running from rechargeable batteries, you may notice more distortion as the system gets into 'brown out' territory if pushed too hard. I would suspect long sustained bass notes would really eat into the battery time. But I understand, you gotta do what you gotta do.

I've got a church customer who uses the Alesis TransActive combo as a portable music system for little outdoor functions.
I've also got a customer using the Anchor Audio Liberty full range PA speakers (one of many battery powered options from Anchor Audio). It all depends on what size audience you're playing for / area you're trying to cover / how loud you need to be.

For a while K&H (Klein & Hummel the high-end studio monitor company, now part of the Sennheiser-Neumann family) sold a self-contained, weather-resistant PA speaker that was rechargeable. I sold a batch of them to a local outdoor venue, and they were very impressive for public address and background music. Needless to say, they sounded exceptionally good, and had a corresponding price tag.

There are probably others, but those are the only three I've personally come across.

I'm assuming a generator is out of the question. A big battery and an inverter are an option too, depending on your application. (Busking, parade float, marching band, outdoor wedding.)

dvdhawk, post: 441644, member: 36047 wrote: I'm assuming a generator is out of the question. A big battery and an inverter are an option too, depending on your application. (Busking, parade float, marching band, outdoor wedding.)

I mis-read that first time as "welding".

Boswell, post: 441658, member: 29034 wrote: I mis-read that first time as "welding".

That's funny. Nothing breaks up a long day of welding like a little keyboard break. Two birds with one stone there though, if lugging around a massive welder is an option. I've run my old PA system at numerous outdoor shows that used a gasoline powered welder as the generator. I can't think of many moments across the entire span of my life, where I've felt such a feeling of relief, as the moment we shut down the blasted (blasting) generator/welder at the end of the day. Despite the facts that it's the end of a long grueling day, the hard part is over, and you're loaded up to the point of just a couple work-lights. After a full day, hitting the kill-switch on the constant, annoying drone of the generator, elicits the biggest collective sigh of relief I've ever heard.

Thank you one and all. Now, back to my welding....

Of the two I mentioned, the Alesis is most like a typical combo amp. The Roland KC-110 looks like it might be promising too. Again, with reasonable expectations.