It's never the machine's fault. It's always the mechanic's or operator's fault.
Maybe a railroad analogy would help you...
Consider the battery as Grand Central Station (GCS). All trains leave from and return here.
All the destinations are double tracked. And a train leaves both Central and Destination at the same time They must. Because there is only space available to store more than one train at GCS.
There are lots of track observers, so if a bridge is out or here is a track malfunction, the trains will stop wherever they are, so they stay on good track.
The wire diagram is the track layout, minus any terrain features. It tells you where the trains/track are supposed to go and usually where all the bridges are.
The meter and its leads present a side path so the impatient passengers can get back to a station via an alternate path They don't do any work on the alternate path beside making vacation plans and then taking them. You can see this activity on the meter. (Eager little deserters, aren't they?)
Anyway, it's a long train that reaches all the way from GCS to where the bridge is out. The meter will show you passenger exodus from the train by moving the probe along the train right up untl the point where the bridge or track is out.
You will find that the terrain is not depicted on the wire diagram, because the terrain is very mountainous and most of the track is deep within tunnels. So, you check for passenger exodus at all the open bridges and only excavate the tunnels when you know that the train is stuck between obviously good bridges.
Hope this helps,