Hi, update to my previous posts.
I have first received a new battery from FP2 for free following the ticket I raised.
I tried it but it would not charge.
I have went back to the same email thread with the initial ticket raised and requested a bottom module.
When I received it and installed it both batteries were able to charge normally so it does seem to have been a problem with the bottom module after all.
I would suggest you follow the tips in this thread straight away when you see your battery discharging quickly and then raise a ticket as the response times from customer support are long but they do come back to you in the end and if under the warranty still will send you components for free.
Good luck. I love how the FP2 zooms around compared to the other mobile I had to use in the meantime.