Can you replace OLED battery with the OG (LCD) battery?

I know the OLED has only just released not that long ago, but I was wondering if like I only have the 40Whr battery for replacement, like is it ok to put it inside the OLED to replace? (I know OLED uses 50Whr, but I just wanna make sure if it's ok to use it wise if there's no 50Whr battery replacement out yet)