its been more then 15 days i disconnected the battery from bv6000
but now when i reconect the battery & trying to on the phone the BLACKVIEW logo comes up for 25-30 seconds & then rebooting again & again, even after connecting the charger to the phone the battery is not charging and phone showing the BLACKVIEW logo and keep restarting like a loop
what to do now i replaced the battery with a new 1 but the problem is same......what to do now

You could try to flash a new ROM over a Computer. If you don't damaged/forgot something while replacing the battery that should work.