RTC Battery Type for S10 SoC Dev Kit?

I have a S10 SoC Dev Kit. I’d like to use the onboard RTC for keeping proper time in Linux between power cycles. However, I don’t know which battery type is required in the BT1 slot on the board. I incorrectly assumed it was a CR2032 which is what I’m familiar with for RTC but a CR2023 isn’t even close to fitting. The required battery needs a much smaller diameter than a 2032 and also needs to be thicker than a 2032. Can someone please tell me what the expected batter type/model/size is?