another deep cycle Battery question

my solar system is 180 watts, 2x 105 ah Batteries. 6 months old
it usually floats on 14 .2 volts.
accidently left fridge on 12 volts for 3 /4 days,only realised when water through fridge.
system will only charge to 3.7 volts then float.
van has a projecta charger installed to charge when on 240 volts
have tried another charger on batteries (projecta 8 amp)
still only getting 13.7 floatcharge

Is it possible to get batteries back to 14.2 float?
Barry Perth