Huawei band 5 not charging

[demusss]

I have a Huawei band 5 which was left for about 6 months. Was working fine but now it doesn't charge up and switch on.
I guess it's because the battery has discharged too much. Is there anything I can do to get it going again?

 

[demusss]

It's been plugged in overnight.
I can't find any where selling replacement batteries