I remove the charged batteries from my laptops and store them in the refrigerator. Every 6 months I recharge them if they have been unused in the meantime.
Like most batteries their life is longer when kept cold.
As to why a Sony might malfunction without a battery, then I have no idea. The Sony (and any laptop) certainly won't tolerate power failures without a battery! :)
I hardly ever use my laptops on the battery. I've never had any trouble doing this. I really buy laptops because they take up less room about the place than a desktop does.
Ross