My charging cable of Olight R50 pro was broken for one month time. While I was waiting a new cable from china, the battery voltage dropped too much. Now it doesn’t start to charge. Is it any possibilities to wake up the battery? And what shop sells a new one with delivery to Finland?
I once got that problem… I had to buy a new battery, no way to wake it up for me 
Check on Amazon, they have it.
Be aware that you need the “ultra high drain” one, so don’t buy the one on FastTech (ask me how I know…)
Once, I wrote an email to Olight customer service complaint about R50 USB charger won’t charge battery properly. Two weeks later, I received a brand new r50 tailcap & a new Olight 26650 battery. I’m not guaranteeing this will work in your case, but it’s worth a try!