ok I have some pics from Duckwonder. the pic of the solar panel is not good enough to try to figure a size. it would help if you could get an above shot here's some ideas,
friends with a balcony you could park the van under and get a picture from the balcony.
put your camera on a stick to get it above the panel.
a parking garage you can park next to and walk up to the second level to get a pic.
any type of building with a second story window you can get a above shot out of.
a loading dock you could park next to.
a youngin you could ask to get a pic for you.
so know on to the pics I have. I am only going to show the important ones.
the warning label.
I posted this because it doesn't say the van will not move but don't move it if the battery is not locked in place.
the infamous battery lock,
this appears to be a pin that simply goes down though a hole maybe it's a bit out of alignment. try to spray some penetrating oil around the pin where the arrow is let the oil run all the way down the pin while you move the pin back and forth. no need to try to pull up on the pin until you get the lower portion of the pin well lubed. then try to lift as you twist. it should free up.
the second battery,
we need to find out where these cables go I put the yellow circle in. from your voltage check they appear to be connector to the main battery somehow and a solar charge controller. but we simply don't know. highdesertranger