Notebookcheck Review for those interested.
In summary, the battery life is good, better than OP13 in the Wifi and H.264 video playback tests.
But the 8 Gen 3 gets throttled really hard in the OP13R and leaves a lot to be desired in the sustained performance realm.
Something notable would be the average and max. idle drain of the 13R compared to other 8 Gen 3 smartphones; the 13R's idle consumption is 38% and 32% higher respectively. I'd wager the battery could be stretched a little more if this idle drain is optimised.