BRIGENIUS Battery Operated Stroller Fan, Portable Clip on Mini Desk Fan with 2600mAh Rechargeable Battery, USB Powered Clip Fan for Baby Stroller Office Outdoor Travel https://www.amazon.com/dp/B078N1MRZR/ref=cm_sw_r_cp_api_glt_fabc_SWJ6F8H1QX8ETGP3QF3K?_encoding=UTF8&psc=1

We have this one. It works well enough. I’d bring an extra battery or two for all day use.