Regional Jet 900 (CRJ900)
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Procedure
While checking the Aircraft Maintenance Log (AML) I noticed an entry 'Main Battery showing 8V on initial AC Acceptance.' The corrective action: 'Charged main battery through external power system; battery charged; system Ops normal CRJ900 AMM 24-00-00.'I have always felt uneasy about charging depleted batteries installed on the aircraft using jet bridge power due to the risk of battery overheat and thermal runaway. I have done some research of my own and found that Advisory Circular (AC) 00-33A covers the subject handling of NiCad batteries. It would appear that maintenance is not following the precautions outlined in the AC to reduce the risk of battery overheating and thermal runaway. The purpose of this report is to bring up a possible deficiency in our maintenance procedures. My observations of current practices when charging depleted batteries on the aircraft is that Maintenance (Mx) simply plugs into ground power without observing the precautions outlined in the AC.I would suggest Mx reviews procedures associated with charging depleted batteries on aircraft to determine if they are adequate.
CRJ-900 flight crew was unsure if Maintenance used the proper procedure to charge the battery.