Please refer to the attached photo. I wish I were better at drawing wiring diagrams. Hope it is clear. Did the following steps:
1. Charged system using shore power charger on batt 1, with echo charge to batt 2
2. Disconnected charger
3. Reading at each battery with DVM: Batt1 voltage 13.26, Batt2 voltage 13.1
4. Reading at analog volt meter on panel: both batteries >13.0 (so, close enough for government work and purposes of this exercise.)
5. Let sit over night (about 12 hours)
6. Reading at each battery with DVM: Batt1 = 12.8, Batt2 = 12.79
7. Disconnect both wires from negative post on Batt2
8. Reading at each battery (with DVM) continues to be 12.8 and 12.79, respectively.
9. Reading at analog volt meter on panel: Batt1 between 12.7 and 12.8, Batt2 showing between 12.4 and 12.5
NOTE: The 10 watt solar panel was connected as shown, but taken out of play by putting it in a locker. Also, all wiring is of sufficient gauge based on many suggestions here as well as MaineSails excellent article on this subject.
Why would I get anything above zero for Batt2 on the analog volt meter if there is nothing connected to the negative post on Batt2?
S/V Wind Ensemble
1987 C-36 Wing Keel
Universal M25XP 23hp
Hull #705
Coastal Alabama
The way you show your volt meter wired is a bit misleading. The stock config would be a three pole toggle switch where two of the poles are used to select the two banks and the the third pole of your switch is actually the positive meter lead. There is a negative meter lead and this connects to ground. Thinking about this ground lead is where your answer might be.
Given that your house and start batteries after sitting overnight have only a .01 volt difference strongly suggest that the positive terminals of your battery banks are in parallel. Is your battery selector switch set to "both" or "all"? If so, all you're doing is really measuring the bank that is grounded. The other bank that is not grounded is just along for the ride.....
Nick Caballero
Retired C36/375IA Mk II Technical Editor
Volt meter is wired as you describe. I left that implied.
switch selector was "off".
turns out the voltage was coming from the echo charger. When I take that out of the loop, the voltage for batt2 reads zero as expected.
Thanks,
Jeff
S/V Wind Ensemble
1987 C-36 Wing Keel
Universal M25XP 23hp
Hull #705
Coastal Alabama