Skip's Corner

Can not locate wiring changes made when ACFT went from NiCad to Lead-acid

The Question –

Working on King Air 300 FA-85 with RG380E/44 installed. Have a minor issue with the Battery charge annunciator and can not locate wiring changes made when ACFT went from NiCad to Lead acid. If you could assist or point me in a direction who could please do? Thanks for your time.

The Answer –

The CONCORDE King Air STC does not disable this system. The light is on as long as at least 7 to 10 amps are charging the battery. Normally, with a healthy battery the light goes out before takeoff.

Most of the NiCad's are 20 cell and the charging system is set upwards of 29DCV which is too high for our 24V batteries resulting in the charge light staying on for a long time. THE CHARGING SYSTEM MUST BE SET PER THE BEECH MM AT 28 TO 28.5 DCV for Concorde Sealed Lead Acid Batteries.

The reason we like to leave the charge light system functional is that it is a CURRENT SENSING SYSTEM. If the light comes on during flight it indicates signs of an internal short. The pilot merely disconnects the battery. If later the generating system were to fail this battery that is fully charged can be put back on line to support the load requirements.

Other approvals provide the option to ground the system rendering the system inoperable if the charge light is a nuisance to the operator.

Skip's Corner

Can not locate wiring changes made when ACFT went from NiCad to Lead-acid

The Question –

Working on King Air 300 FA-85 with RG380E/44 installed. Have a minor issue with the Battery charge annunciator and can not locate wiring changes made when ACFT went from NiCad to Lead acid. If you could assist or point me in a direction who could please do? Thanks for your time.

The Answer –

The CONCORDE King Air STC does not disable this system. The light is on as long as at least 7 to 10 amps are charging the battery. Normally, with a healthy battery the light goes out before takeoff.

Most of the NiCad's are 20 cell and the charging system is set upwards of 29DCV which is too high for our 24V batteries resulting in the charge light staying on for a long time. THE CHARGING SYSTEM MUST BE SET PER THE BEECH MM AT 28 TO 28.5 DCV for Concorde Sealed Lead Acid Batteries.

The reason we like to leave the charge light system functional is that it is a CURRENT SENSING SYSTEM. If the light comes on during flight it indicates signs of an internal short. The pilot merely disconnects the battery. If later the generating system were to fail this battery that is fully charged can be put back on line to support the load requirements.

Other approvals provide the option to ground the system rendering the system inoperable if the charge light is a nuisance to the operator.