UC Davis Institute of Transportation Studies

The use of lithium titanate Oxide (LTO) batteries with supercapacitors in micro- and mild hybrid vehicles has been studied. The study involves vehicle simulations and laboratory tests of carbon/carbon supercapacitors and 20Ah LTO cells from EIG, Korea. Cycle testing of the LTO cells/module on a cycle to simulate their use with supercapacitors indicated that their charge acceptance was excellent even at a charging power of 2000W (500W/cell). The test data indicated that the LTO battery would be an excellent choice for micro-hybrid applications. Simulations of micro- and mild hybrid vehicle operation have been run using lead-acid and EIG LTO battery technologies in 16V and 48V system. It is clear from the results that the LTO batteries can function well in both the micro- and mild hybrids. The LTO batteries are much smaller than the lead-acid batteries and are more efficient. The LTO batteries had an efficiency of 95-97% while the lead-acid batteries had an efficiency of 85-88%. The effect on fuel economy of the higher efficiency of the LTO batteries was not significant for either the FUDS or highway driving cycle. This was true for even the accessory load of 800W.