Hi, The mower has been working fine thru the summer but about 1 month back, I couldn't get it started due to low voltage(was showing 9.x on the mower's voltage meter). So, I put the booster battery on and I could jump started it at that time. A few days after I tried to start it and it worked fine. But today I tried to use it, it wouldn't start again. I slow charged the battery to 12.5V but when I turn the key to on, the voltage meter shows 9.5-10.0 immediately. It didn't even click when I turned the key to start position. When I turned switch off and measured voltage at terminals, it still showed 12V. But once I switch it on, the voltage dropped. I cleaned all the ground points I could find but was still the same. And I couldn't even jump start it. The voltage meter on the booster would drop to the same reading showing on mower's voltage meter. Does that mean the battery is dead? If so, why it still shows 12V at terminals after I turn the key off? And if it's battery, I should still be able to jump start it, right? Or do I have a bad solenoid? How do I further troubleshooting it? Thanks in advance!