Check if the wire between your
solar controller and
batteries has a large voltage drop across it. To do this, run a voltmeter between the + on the controller output to the
battery and the + on the
battery (so you are just measuring from one end of the wire to the other). Do the same for the -ve wire.
If you measure a voltage that is more than a few tenths of a volt, then you need to determine why. There are two likely reasons:
1. Your wire is too small. Check the AWG vs length is appropriate for the anticipated
current. Err on the side of too big, because when you have 10 - 15 amps flowing in it, it gets hot and the resistance goes up, and the voltage difference increases. A bigger wire stays cooler because it has a lower resistance.
2. The connector at the controller to your wire (either + or -) has a fault and is not making a good connection to the wire. Try jiggling the wire at the both ends and seeing if you can detect a change in the voltage read by the 2000e. This can be a bad connection inside the 2000e or it can be a bad connector on the wire.
A few months ago, I had a 2000e fail in this manner (2, connection at the controller was bad) while I was near the end of a pacific crossing to
Hawaii, and I am in the process of returning it to Blue Sky to find out how much they will charge to
repair it. It destroyed my
batteries because it thought the batteries were fully charged, but they were not. I did not have a low voltage cut-off. I do now!
I do not understand the 19V
alternator reading. That's weird. Suggests your alternator
regulator is toast? What does your DVM read at the battery when your alternator is running and the 2000e says 19V? What is the voltage difference across the wire then?