Apple Watch didn't last a marathon

HI all,

i ran a marathon last weekend with my husband. We are not very quick and our time was about 5.5 hours. His watch lasted the whole marathon and into the next day and mine packed up at 23 miles though both had been fully charged (his is the bigger model). As far as I know, our settings will be similar as we haven't changed them much. Normally I listen to music on Bluetooth headphones when training, but could see that the battery had drained 3% after five minutes so disconnected them, but that wouldn't account for the big disparity in the two watches.

Any advice please on how to get it to last for 26 miles? I don't take my phone and have taken off most notifications so I don't get reminded about doing things. And I would rather be able to see my stats while I am running if at all possible as it is a good motivator for someone not that good at running.

Thanks.