Tesla will move ahead with adopting improvements to the low-voltage system of its EVs, till now the EVs are operating at roughly 12V, but now a 48V low-voltage system.
Representatives from Tesla confirmed the intention to introduce a 48V system, during the 2023 Investor Day. 48V system is available for many years but still it a very less adopted solution in the automotive industry.
Lithium-ion auxiliary batteries
As the first step towards a new voltage system, Tesla switched from 12V lead-acid auxiliary batteries and adopted 12V lithium-ion auxiliary batteries. The old lead-acid batteries were a significant reason for failures in Tesla cars. Lead-acid auxiliary batteries need a replacement in almost four years or so. Interestingly the 12V lithium-ion auxiliary batteries are expected to survive the lifetime of the car, simply as the main traction battery. So, there will be no need for battery replacement at all.
No need of battery replacement is not the only advantage but the smaller size and lower weight, nearly 87% mass reduction are additional benefits from 12V lithium-ion auxiliary batteries.
The 48-Volt System
Tesla will use the 48V low-voltage system in the upcoming Cybertruck in 2023, and in all future electric vehicles. Just to add the auto industry shifted from 6V to 12V in the 1960s. Currently, some of the larger vehicles use 24V. The 48V system will be adopted by Tesla, as it will reduce the current by a factor of 4 if compared with 12V systems. The 48-volt level is considered safe.
As the power requirement for onboard electrical devices is increasing steadily, an increase in voltage is inevitable. If we use 12V for this much power requirement, the wires required will be thick, and heavy, and will cost more. Interestingly when a 48V system is adopted, there will be significant savings in weight and cost. The 48-volt system may also increase efficiency.
It is necessary to add that the change to 48V will also require a new 48V lithium-ion auxiliary battery. This battery might even be produced in-house, let us see.