Fully charged battery voltage is ~12.6v
Battery Approximate Average Cell
Voltage State-of-charge Specific Gravity
12.66 100% 1.265
12.45 75% 1.225
12.24 50% 1.190
12.06 25% 1.155
11.89 0% 1.120
from
http://www.type2.com/library/electrip/batfaq.htm
You might also want to measure battery voltage with another multimeter. 10.6v sounds really low. Given it still can start your car, its real voltage might be higher than measured.
Battery Approximate Average Cell
Voltage State-of-charge Specific Gravity
12.66 100% 1.265
12.45 75% 1.225
12.24 50% 1.190
12.06 25% 1.155
11.89 0% 1.120
from
http://www.type2.com/library/electrip/batfaq.htm
You might also want to measure battery voltage with another multimeter. 10.6v sounds really low. Given it still can start your car, its real voltage might be higher than measured.