Why would replacing the battery make any difference?
These may help. They may also give you better informed places to post your own question there.
http://www.bba-reman.com/forums/topic91864-1-1.aspx
https://www.honestjohn.co.uk/forum/post/index.htm?t=67080
https://www.peugeotforums.com/threads/2004-307-sw-1-6-hdi-brief-engine-cut-out-while-driving.194354/
https://www.autoinsider.co.uk/problems/peugeot/307/13352/peugeot-307-engine-cutting-out
https://www.autoinsider.co.uk/problems/peugeot/307/5047/peugeot-307-engine-cuts-out-when-car-slows-down
3jrhgf, November 2021
