X2 on the convert part. Your converter may only go to 13.6 volts and possibly only see 13.5 or 13.4 at the battery. When the battery is fully charged and the converter goes into float it will sit at 13.2.
There is a big difference in that and an upgraded model that does 14.4 or even 14.8.
I have helped several people in our travels with dead batteries. One guys batteries were so dead and his converter was only able to put out 13.6 v I told him it will take a couple days. After several hours the specific gravity started to rise but he told me my hydrometer was broke and it couldn't possibly take that long. He also said he had been making cakes and stuff with his inverter and four old gc2.
