Stansbury Scarf charger hits gassing after 10mins and then says charge completed after another 10mins. Bauser BDI read one light after charge. Acid levels were to low to take SG. I topped up battery and put on charge. Charger turned off after about 20mins again. BDI then read full. I'm thinking I should get customer to charge it a few more times so I can take accurate SG readings and load test each cell. I've checked all BDI settings are correct.Charger was charging at 26.8v @ 30A. I've heard sulphation can cause chargers to turn off early. Any suggestions or input would be greatly appreciated.