Damage to Power Board upon Battery Replacement in G5 ventilators.

We have had numerous Power Board failures upon replacing batteries in our Hamilton G5 ventilators. Each time costing us well over 2K to purchase new replacement boards. I am told through the grapevine that GE was aware of this and that it does not happen after a certain revision or serial number level. Does anyone know what can be done to correct or prevent the issue on the older boards? GE has not accepted blame for whatever causes it or informed us of what is different with the newer boards to prevent the issue. One of their field techs told us it is a 50-50 gamble of whether it happens or not so they always carry a new board along when they are changing out batteries.