06RTCharger

in Either i didnt use the dmm the right way or its more complicated than i thought lol. My dmm read 11.5 v on the battery while car completely off. Figured the battery was fine and something technical was wrong. Scheduled an apt at the dealers and a towing from AAA. Aaa said they could come take a look at it and see if they can help any. They hooked up a charge and the car started less than 10s after they hooked it up!? Lol wtf. The guy said the battery was really low, around 7v!? He said his machine simulates the car starting up or something, thats why my dmm read 11.5v but his charge machine read 7v??? Whats the deal wih that, can someone explain how that works just so i know a lil more. 

His machine also shows the alternator is fine so he thinks i mustve left a light on or something and thats why it was dead in the morning. Glad thats sorted out for now. Hopefully thats all it was. How do i make sure my battery is good? If it went down to 7v is it gonna be able to hold this charge? After a few mins of being hooked up it was back to 12v. seems super fast .