Joovv go battery

So just over a year, my Joovv go red's battery is nearly dead. 24 hours of charging with official charger and cable gets me a 6 min session! My Joovv go infrared is going slightly better at 30-40 min per charge. Emailed Joovv support and got the standard out of warranty response. They want me to ship it to them to assess for repairs and and then if I agree they'll proceed. It costs me 70+$ to even ship it to them, given I'm in Australia. I was hoping they'd just send me a fresh battery (happy to pay for it!) to replace or even better just bypass the battery so it works as a simple mains connected red light. Anyone has experience on the Joovv go replacement battery or how to bypass battery and get it to just work when connected to charger?