Before we go on that Ryzen and AMD thing, youhave to make first a decision between battery live and performance.
If you want performance, those desktop replacement machines e.g. ROG laptops will have bad battery live, all of them with no exception.
Mostlyor in general, the weaker the laptop is the longer the battery live will be.
This is the reason why I went for PC and laptop solution.
Now, about Acer, I do not want to bad talk Acer products but I had only bad experiences with this brand. Mostly because, that their laptops are hot. Literally hotter than similar laptops from other brands. They also went broken faster than other brands due to heat. I would take other brands.
Acer laptops tend to be cheaper than from other brands with similar specs, this comes with reasons.
OK, now about the Ryzen and Vega stuffs, are you planing to get those Ryzen 5 with Vega as iGPU (2500U or 2700U) or normal e.g. Ryzen 5 1600+RX580?
If you want 1600+RX580, you can get this GPU only on desktop replacements like ROG. This will not have good battery stamina.