By your description you are saying the LED 1 flashes 15 times, then LED's 3 and 5 flash once?
This could possibly be this problem:
Battery Testing Error - Sulphate / Discharged: This error is only generated by one of two conditions found during the Pre-Qualification-Test Charge Stage: o Sulphate: Severely Sulphate battery plates are preventing a charge flow from increasing above a minimum value. Disconnect and reconnect AC Power to charger to restart this stage. If a second attempt failed, load test each battery and replace any failed battery. o Discharged: A severely discharged battery did not charge up to 1.75Vdc per cell ( for example - 21Vdc for 24V-battery ), within an allotted time span of approximately 4 to 8 hours. Check for heavy loads preventing battery from increasing charge and/or defective batteries that will not accept a charge.