12 V vs. 48 V

[EVCar]

Just came across this interesting article:

MSN

 

[Impatient7536]

what sort of improvements can we expect with 48V batteries? other than having less instances of dead 12V batteries bricking a car, are there certain hardware, features, etc that will be available when running 48V?

 

[Steveinarizona]

Just came across this interesting article:

MSN

I have been waiting for this to happen. There has been much talk of it in the automotive press (going to 48 Volt; not necessarily Tesla).

 

[Tesla2.0]

I watched that 4+ hrs Investors Day on Tuesday. I believe it is revolutionary. And perhaps advanced EV like Lucid Air with 90+ subsystems can now wake up faster in communication and less laggy being powered up at beginning by 12V. Alternators can also put electricity back faster with less resistance, so perhaps we don’t see car bricked like 12V issues back then.

 

[Shuasha]

I understand the "lower resistive losses" argument, but what % of the energy is lost in 12v compared to 48v? Thinner wires are lighter and cheaper, but doesn't that increase resistive losses compared to the thicker ones, negating some of the gains?

I'm certainly not against something like this, but I guess I'm missing the big motivator that would overcome the large costs associated with redesigning all of the electrical components and remove most of the off the shelf parts currently in use.

 

[joec]

I understand the "lower resistive losses" argument, but what % of the energy is lost in 12v compared to 48v? Thinner wires are lighter and cheaper, but doesn't that increase resistive losses compared to the thicker ones, negating some of the gains?

I'm certainly not against something like this, but I guess I'm missing the big motivator that would overcome the large costs associated with redesigning all of the electrical components and remove most of the off the shelf parts currently in use.

It has to be cost-cutting somehow, or Musk wouldn’t be doing it. That seems to be the primary motive at Tesla lately.

 

[MoniputerLM]

It has to be cost-cutting somehow, or Musk wouldn’t be doing it. That seems to be the primary motive at Tesla lately.

Lower production costs should be a priority. It's how to stay in business and sell more cars.

 

[Tim-in-CA]

It has to be cost-cutting somehow, or Musk wouldn’t be doing it. That seems to be the primary motive at Tesla lately.

I believe it also simplifies the power electronics and has the potential to reduce cable gauge, length and number.

 

[Tesla2.0]

48V Lithium-ion Battery vs. Lead-acid Battery​

Energy density by weight

At present, the energy density of lithium battery is generally 200~260wh/g, while that of lead-acid is generally 50~70wh/g. The weight energy density of lithium battery is 3~5 times that of lead-acid, which means that the capacity of lithium battery is three to five times stronger than that of lead-acid battery under the same weight, so lithium battery has absolute advantage in energy storage.

Volume energy density

Since the volume energy density of Li-ion battery is usually about 1.5 times that of lead-acid battery, Li-ion battery is about 30% smaller than lead-acid battery in the same capacity.

Service life

The most popular lithium battery materials are lithium ternary and lithium iron. For example, ternary lithium batteries usually have 1000 cycles, lithium iron phosphate batteries have more than 2000 cycles, and lead-acid batteries usually have 300-350 cycles. Then it means that the life of lithium batteries is about 3-6 times that of lead-acid batteries.

Price Cost

Lead-acid batteries are currently cheaper than lithium batteries, which are about three times more expensive than lead-acid batteries. However, by lifetime analysis, lithium batteries have a longer lifetime if the same cost is used.

Environmental Protection

Lead-acid batteries are very polluting, while lithium batteries are relatively greener in terms of production and recycling.

What is 48V Lithium Battery?

48V lithium batteries have many applications in real life, such as home battery energy storage systems, telecommunication batteries, data center backup power supplies, etc. So how much do you know about 48V lithium batteries? We have collected and sorted out some information about 48V lithium...

www.loomsolar.com

 

[DeaneG]

48 volt systems have been discussed for a long time in ICE cars to reduce the weight of wiring and reduce starter motor current etc. I don't think it makes a big difference in an EV, as there is no starter motor, and the PTC heater runs off 400V anyway. Maybe electric-assist power steering could be a little lighter. As far as powering electronics goes, it makes almost no difference. It's only marginally easier to power a 150W ADAS computer on 48V vs 12V.

A 48V car battery has 4x as many parts as a 12V. No savings there. Lithium-ion vs lead-acid is a separate discussion unrelated to 12V vs 48V.