still 1.9v per cell is low like a discharged battery.
If you put it on charge and it improves then recheck the operation and see if codes come up.
If after charging the voltage does not rise as it should then i'd say the battery may be badly sulfated. Do a SG check on the acid and make sure it is ok, low SG/acid levels can also be a big reason batteries do not hold or charge up like they should.