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shahone
18th Jul 2011, 19:16
Hi!
I am conducting a study about differnt battery technologies used in aircraft as a part of my masters degree project. At this point, my intention is to gain insight into how big the batteries are, regarding capacities - Amp-hours, which are installed in large aircraft. The aircraft include A319-A340 and the big boeing jets.
Could you guys share your knowledge on this subject, i.e. which airplane has which battery of what capacity? (e.g. Airbus A330, Sealed Lead Acid, 24V 44Ah??)
I thank you all in advance

STBYRUD
19th Jul 2011, 13:36
I can only speak for the 737, that has a NiCd battery with 36Ah @24V (20 cells), the NG has two of those installed to give roughly 60 minutes of standby power. Well, certain parts have their own batteries (like the fuel shut off valves and the ISFD) but I don't know what kind they are...

autoflight
23rd Jul 2011, 04:21
There are lots of batteries. In aircraft I have flown, usually 2 large lead acid batteries to start the Auxiliary Power Unit (APU for engine starting and to provide air, hydraulics and electrics for other services) and to provide DC power for essential equipment when all other DC power (including from the APU) has failed. That same battery power can sometimes power an inverter to run an emergency artificial horizon and perhaps other instruments.

Emergency exit lights are powered by small rechargable batteries. There could be several of these on a regular sized airliner and more on larger aircraft.

Emergency hand torches often have rechargable batteries. When they are in their stowed positions, they are charged.

Emergency radio beacons have batteries. The Flight Data Recorder and Cockpit Voice Recorders have batteries to power an acoustic pinger (about 30 days) to help with underwater searches for these 2 black boxes which are usually orange.

Some crew members may have their own mobile phones, emergency beacons with dry batteries, or even satphone.

There can sometimes be a Ram Air Turbine (RAT) that can can drop out into the slipstream, providing essential services including limited electrical power.

When all other electrical power is unavailable, the main aircraft batteries on an Airbus A320 provide up to about 30 minutes of mininimum electrical power for flight instruments and other really essential equipment. I think this is typical battery capability on medium range aircraft like this.

You have a big job to collect this information and it would be best to talk to an aircraft engineer who specialises in electrics.

Graybeard
23rd Jul 2011, 12:53
A flashlight (torch) is a container for dead batteries...

mono
23rd Jul 2011, 13:13
I'm not aware of any large transport a/c (i.e. with an APU) with lead-acid batteries. NiCad's have a much better capacity for a given weight/size and are generally used.

There are however many GA a/c with lead-acids fitted.

Boeings use 36-40 AH batteries, usually 2. These are normally split and a single battery is used to start the APU when there is no other electrical source, with an APU start TRU to do so if there is normal power supplied. In the event of a total AC power loss, the batteries are tied to provide emergency electrical power for a prerequisite period which can vary depending on the certification requirements (ETOPs, etc.). Boeings also tend to use a dedicated battery charger to charge the batteries (a reflex/pulse type to help prevent cell memory issues)

Airbusses (Airbii???) 0n the 320 series at least use smaller 23AH batteries which are tied to start the APU (there is no APU start TRU on the 320 series) and to provide emergency electrical power. The A320 series simply connects the battery to the DC busses via battery charge limiters for charging the batteries. this set up doesn't seem to cause any cell memory problems tho' when I first learnt of it I thought it was a little unusual.