I still have many random codes, but battery are nearly dead, they won't charge over 2volts each and acid gravity stay very low. My manager do not want to put 3000$ batteries into a 20 years old lift. So i have to stop investigation there.
Thank's to all

Post if you still have codes after the battery is fully charged.

Thank for your help. I finally found the trouble. I checked the charger and understood it work that way: If no battery is connected, AC is completely disconnected by a master relay. Controller board is feeded by the 48v from the batteries when connecting the lift batteries. Then, the controller make an analysis of the battery state, end if they need charge, it turn on the master AC relay that feed the transformer. It is this master relay coil that was melted. It work fine now. Your suggestion guided me on the right path!

The battery is dead and by the info given it may need to be replaced. You may be able to get the charger to turn on and charge if you hook up a 12v car charger to six cells at a time and charge them for a little while and keep doing that until all 24 cells have bee done and you get at least 48.5 volts. It sounds like the charger is an automatic turn on and is doing an evaluation of the battery and it doesn't have enough power for the charger to recognize it and turn on. As for the codes they could be any number of things but I am willing to bet that it has a main card issue, especially if it was left outside for 2 years. It may not be worth it to get it going.