I assumed by the noise it was making, buzzing followed by silence. When I plugged it in and attached it to my mower battery it lite up and seemed to be in a cycle of charging. I used a 50A Auto Automatic Reset Stud Type Circuit Breaker for the thermal fuse. I replaced the relay with the same Songle Relay SRU-06VDC-SL-C type. I inspected the insides and found that the thermal fuse was melted and a relay had burned out. I was attempting to charge my riding mower battery when it fried.
I have a Harbor Freight Cen-Tech Battery charger SKU 60653.