On Sep 24, 10:30*am, Mike McCarron wrote:
Power Sonic Model PS-1290 F2 Sealed Rechargeable

http://tinyurl.com/c4n9hem

This battery is rated for 8.1 AH @ 810mA, when discharging to 10.5V.

The manufacturer's discharge curves suggest that if 11.6V is your
minimum, then you should get approximately 8 hours out of your battery
at 0.8A. Obviously, something is wrong.

There may be a voltage drop somewhere in your installation. This would
not affect open circuit measurements, but could be significant under
load. Where do you measure battery voltage? At the battery terminals,
at the panel?

The manufacturer says "Charge until battery voltage (under charge)
reaches 14.4 to 14.7 volts at 68°F (20°C). Hold at 14.4 to 14.7 volts
until current drops to under 90mA." Can you verify that this is what
your charger is doing?

Bart