Bluetooth headphones battery life

[jmn]

I bought an over ear set about 3 years ago. Used them quite a lot in the first year and then put them away. Working perfectly at that point.

2 years on they don't work anymore. I believe that they are powered by a Lithium battery.

Battery does not appear to be replaceable.

I found a report from Which online which goes into the battery problem and concludes that with normal use you might get about three years use before battery failure. Apparently these batteries can only be charged a limited number of times.

Do Lithium batteries deteriorate if not regularly discharged/recharged?

Has anyone here managed to replace the battery in one of these headphones?

Are any headphones sold with replaceable batteries?

[mgv8]

Do Lithium batteries deteriorate if not regularly discharged/recharged?
Don't leave 100% flat, don't change to 100% if hot. Over all they will fail over time as well as charges.

Has anyone here managed to replace the battery in one of these headphones?
Yes but was not easy, and was lucky, could work out what battery they used so found one online.

Are any headphones sold with replaceable batteries?
I found what battery they used and from part number got one. I have not see this service on-line.