Your meter looks like a knock off of a Fluke meter...Most meters of this kind do not but a load on the system being tested...so all you're reading is voltage without any load applied....once a load is applied voltage can drop off to unsafe levels.....
I remember reading a magazine story a few years back where a group of folks were involved in a big scale event..it's like day 3 or so and they have a good chance of winning...I can't remember the details.. they checked the batteries with a fluke meter, had good voltage...the aircraft crashed on final....after the crash they checked the battery voltage under load and lo and behold...unsafe