The Cessna Citation CJ4 is currently the only business jet certified with (but no longer flying with) a lithium-ion main-ship battery, using lithium-iron phosphate, not the lithium-cobalt oxide battery found on the Boeing 787, which is currently grounded in the wake of battery fires. FAA special conditions were issued for certification of lithium-ion batteries in the new Sovereign; similar conditions applied to the CJ4. In 2010, Cessna also announced plans for “dual lithium-ion batteries” in the new Citation X.
However, CJ4s no longer feature lithium-ion batteries, after a main battery fire on a CJ4 plugged into ground power resulted in an AD mandating replacement with nickel-cadmium or lead-acid batteries. The FAA “discovered that the cause [of the CJ4 fire] was that a mechanic had intentionally bypassed the safety systems built into the battery,” an FAA spokeswoman said.
Only two other business jets were slated to have lithium-ion batteries and were issued special conditions to do so: the Spectrum S-40 (since canceled) and the Gulfstream G650. “The G650 has lead-acid and Ni-Cad batteries,” a spokeswoman for the OEM told AIN. “Early in the G650 program, Gulfstream did investigate using Li-ion batteries. However, we made a change during the development program to today’s batteries.”