https://www.thecalculatorsite.com/co...watts-amps.php
250 watts makes 20+ amps at 12V. With a shurflo or equivalent pulling up to 10 amps, you should have a 10 amp surplus to charge the battery during sunlight hours if your panel is producing 100%. There are lots of variables though, and in my opinion, and what I am doing this year is running two batteries on each pump and using a temp controller to switch the pump on & off. I used 100 watt panels last year and would get about 4 days out of a battery- I have an additional panel and battery for each shurflo this year and with t he addition of temp controllers, I won't have to be 4 places at once to turn the pumps on when the woods thaw. Good luck!
2012 15 jugs
2017 125 3/16 -18"x 6' drop flue, home made arch
2018 240 3/16 -Deer Run 125 RO
2019 450 3/16 -converted RO to electric, added a membrane
2020 600 3/16 -Maple Pro 2x6 Raised Flue, added AOF/AUF
2021 570 3/16 -built a SS steam hood, new Smoky Lake SS filter press