Airbus has reached the final stages of regulatory reviews over a plan to use Li-Ion (Lithium-Ion) batteries for backup and starting power on the A350-900.
Well known safety problems with Li-Ion batteries on the 787-8 and other aircraft have stretched the regulatory review process.
“We might have to do a few more tests because the authorities are extremely nervous on the subject because of the Boeing 787”, said Charles Champion, the exectuvive vice-president of engineering.
Airbus has already decided to make a design change to the original battery system for the A350-900.
The original design allowed power to flow between batteries, but that raised concerns that one overheating batter could cause another to fail.
“So we put in a non-return valve so that if it blows out, it doesn’t go back in the other batteries.” Champion says.
Airbus is still trying to persuade the authorities that it is safe to install such powerful batteries inside an aircraft with ought enclosing them in a heavy stainless steel box. Saving weight is one of the key advantages gained by using Li-Ion batteries, so the manufacturer hopes to install the batteries in a box made of materials lighter than stainless steel.
Airbus remains confident that the lithium ion battery design for the A359-900 has always been safer than Boeing’s original system for the 787-8, which lead to 2 battery fires, grounding the fleet for four months and forcing Boeing to use a heavy stainless steel box.
The 787 uses two GS Yuasa-made batteries with eight 3.7V cells each, storing a total of 72Ah of power per battery. Airbus instead opted for a more conservative design, selecting four Saft-made batteries with 14 3.6V cells each, storing a total of 45Ah of power.
Airbus also selected Saft to supply the battery and the charging unit, unlike Boeing that chose to divide the system between GS Yuasa and Meggitt Securaplane.