ya there is no resistance in the one that blew, and there is 2Mohm in the one that did not blow.
Just an additional info, my battery is a UNICELL TLA12260 12V 26AH lead acid battery.
and my solar panel is a Sunsolar AS25-12 with Rated Max Power: 25W
Rated Operating Voltage : 17.1V
Rated Operating Current :1.47A
Open-Circuit Voltage : 21.5V
Short-Circuit Current: 1.65A