If you can find a charger that can pump out 800v. Are there any in Malaysia yet?

The Ionic looks like a really interesting car, I think I would have to make a lot of sacrifices to run an electric car though.

These guys are in the process of upgrading to 800v not sure if they have completed it or not.

I dont think you should measure charging speed by volts eg 800v.

The right way is to measure by kW.

For example a 70kW charger should be able to charge a 70kWh car just a little bit over an hour.

If you stay in a landed property, why not?

Keep or rent a petrol car when you need to road trip

when Battery replacement time .. battery cheap already ..

how cheap is consider cheap?
20k 10k or 1k?

we can check Prius and honda insight battery price

unfortunately both car are no longer in the market

battery cheap...
but...inverter still exp

You are not wrong. However voltage play huge role in the high power system, especially a DC system.

for the same 70kW, doubling voltage reducing the current by half.

1) Let's assume perfect power factor of 1.0 for simplicity. P = I^2 * R, high school physic. P = Square of Current multiplied by Resistant.

Use V=IR

70,000W with 400V, current = 175A
70,000W with 800V, current = 87.5A

2) Assume gauge 0 cable (that's very thick 0.855cm in diameter cable on each polarity), the resistance is about 0.0004 ohm per meter at room temperature 25C. Assume a 10m cable, that's 0.004 ohm, round trip = 0.008 ohm.

Use P = I^2 * R

400V, power loss over cable = 175^2 * 0.008 = 245W
800V, power loss over cable = 87.5^2 * 0.008 = 61.25W

You see, significantly less loss over the charging cable wires with 800V.
Furthermore the loss power will dissipate as heat, cause the wire to heat up and increase the wire resistance -> even more loss -> even more heat.

3) Let's not forget the voltage drop over the cable. In the school, on electronics, the current is so small and insignificant, we always assume wire resistance = 0, voltage drop over the wire = 0V.

In high power system, it is different story.

Use V = IR

400V voltage drop over the wire = 175 * 0.008 = 1.4V. Voltage at load end = 398.6V
800V voltage drop over the wire = 87.5 * 0.008 = 0.7V. Voltage at load end = 799.3V

You see wire itself cause voltage drop on the high power system, thus we always have something called remote sensing, where we have high impedance load that run in parallel as the actual application load. Such the the current over the high impedance load is small and negligible, then we can measure the load end voltage drop, and compensate it by increase the source voltage.

So source run slightly higher voltage at source to allow load to actually get 400V, 800V.

4) Lastly, running at 800V system also allow thinner wire due to lower current on the car itself. Thus lower loss + lighter car.

5) So, 70kW at 800V will charge faster than 70kW at 400V due to higher efficiency (provided the the bottleneck is not at battery side, and assume same battery thermal management).

This post has been edited by constant_weight: Apr 7 2022, 08:39 PM

Yikes this is too technical for me already.

For EV users, the behaviour would be to charge their cars at home most of the time right? Even upgrading to a 3-phase, you can only get up to 400V for your home.

So the 7kW charger on a 230V single phase is actually decent enough as not alot of EV cars in the market is equipped with a 22kW on-board chargers. Most of it are capped at 11kW.

Well the Merc e300 hybrid batt alone is RM50K. There are additional charges too!

The other side of the coin is, if one can afford the e300 $50K is cheap!

yeah...tat is only price for the battery...
hybrid to have extra component....which is not cheap...
+ additional ice maintenance or fixes...
so..i think it will be nightmare also....lol

You are right on AC charging that used on-board charger that convert AC to DC. 11kW or lower are all AC. 22kW have both AC and DC variant. Those faster charger eg:. 150kW are all DC.
The DC fast charging don't use on-board charger in the car, it is the car that negotiate max supported charging rate with the charging terminal directly. So that case the limit is not the on-board charger, but the battery type, battery array design, and thermal management.

So far the commercially available mass market EV with 800V are all those have stake in Rimac group. The one that build Rimac Nevera 2000hp+ Hyper EV.
Lotus hyper EV also run 800V, again that's hypercar, not for mass market.

Basically Hyundai Group (Hyundai, Kia, Genesis), Porsche Group (Porsche, VW, Audi) are the 2 mass market brands that have access to mature commercially ready 800V technology.

So 800V are still very uncommon. Even we have 800V charger, very few EV can make use of that. But expect more and more to move to 800V in the future.

Basically something like quick charge for phone lah. Waiting for wider adoption and tech improvement.

50k for 1 whole block of battery? My understanding is that most batteries are now modular. Example, Volvo's PHEV, to replace all is about 40+k, but per block/module is about 5k, which i think still kinda reasonable, unless you unfortunate at the max level.

To make it affordable, we need more 3rd party installers in the market. You are right, if you've seen some videos online, the batteries ARE modular. Not so complex. The cost i think will further go down another 20-30% once 3rd party experts are in.

This could be happening sooner than later.
https://www.wapcar.my/news/china%E2%80%99s-...-families-34850

China’s week-long holiday: BEV owners fight over charging ports, no A/C for families

Especially as more people drive EV, when Raya time or long holidays, can't imagine the queue would be at charging stations.

Actually I don't know details. I think 50K for whole block. Being a Merc I'm sure nothing will be reasonable. Unless OEMs are available, which are not at the moment. Dropped the idea already.

As scary as its sound. I see manufacturer start to develop concept pakai buang already. Go see how conti car force this concept. Rarely see 15 years mercedes on the road anymore. People will change into newer merc or opt for cheaper more reliable jap car. Still got alternative right, but imagine if no got alternative. Like all this EV in the market. Lol.

Imagine need to change into newer EV once car become 15 yo. rofl. In the end, manufacturer won.