So i just bought a brand new echo 1 ak47 ris. I charged the battery for 1-2 hours (not enough , I know) but I shot about 50 rounds out of it and then it just stopped shooting. So then I charged the battery for 2-3 more hours and after a little bit of pulling the trigger it stared firing. After about 100 rounds it stopped shooting again, and then it comes back. It does this quite often and I was wondering if I should do anything different? Just charge the battery more? or if something is wrong with the gun.