Turnigy charger and zippy NiFe battery

Hello, I can’t get this charger to work with this LiFe battery, the charger produces a “balance fault” message… I can’t find any solution. I don’t know if it is the battery, or the charger, but both my zippy 8400 and my zippy 4200 LiFe batteries get the same message, so I think it is the batteries? The charger is the Turnigy Reaktor 300W 20A with a 13.7V power supply Thank you very much, James.