nothing new. camel trophy land-rovers in the 90's had a welder powered off the alternator in the repair vehicles. i have a Rawl plug batter welder at home for the 70's! (granted its totally rubbish and the only time i has been used is when my mates lighter ran out and he sparked it up using the metal bumper on the back of my escort van)
As you said there have been battery welders in the past but the battery life was always shockingly bad and with not much power.
It's a complete new design Li-Ion battery specifically with welding in mind, it's very compact and lightweight and the other key is it's completely rechargeable.
Battery guaranteed at 100% capacity for 3 years or 1000 recharge/discharge cycles and the welding performance is identical whether on normal mains, generator or the last bar of the battery. Will still burn a 4.0mm CEL regardless
Prices still TBC but i expect the machine to be a cheaper than our current Handy 150 (which it will eventually replace)
Battery will be around a grand, so all in all I recon about £1500 for a package but most people will never need a battery so can just buy the machine on its own and run it off the mains.
The Micor160 is drop proof from 80cm, can run on 200 Meter leads, weld up to 4.0mm CEL's and has something called kick arc, which practically eliminates arc blow. It super imposes AC voltage over the DC welding voltage so you don't get arc blow