I'm looking at these two portables, each retailing about $99. What's the difference? I've gone online and they seem very similar. Is one an older model?

Also, they both run on 'AA' batteries. Is this a new thing? The portables I've always had in the past ran on 'C' or 'D' batteries. Do the 'AA' batteries need more frequent replacing?

Thanks in advance.
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Music School Owner
Early Childhood Music Teacher/Group Piano Teacher/Private Piano Teacher
Member of MTAC and Guild