Ask me anything about working as an EV engineer

General
1

I’m a mechanical/electrical engineer in the commercial EV industry. Started at a small startup 4 years ago and now work for a larger company focused on getting commercial EVs into production. Feel free to ask me anything about the work, the challenges, or the industry in general!

Edit: Taking a break for now, but I’ll try to get to all your questions in the next few days!

2

I’m a robotics engineer, so I hope these questions aren’t too detailed. Here’s what I’m curious about:

  • How far do motor controllers go beyond typical FOC control for brushless motors?
  • Does the BMS balance cells individually or just adjust charge rates per cell?
  • Is the throttle map just pedal position → motor amps or is there more involved?
  • Is the CAN bus used for everything, or do cameras use other protocols? We use EtherCAT for robots because it’s more reliable.
  • Have you seen spectacular failures during testing?
  • What are some design headaches EVs avoid? What new headaches do they introduce?
  • Is making the car work with all chargers a challenge, or do most chargers follow standards well?
  • What safeguards are in place to prevent runaway motors from bad code? Is there a hardware failsafe like an emergency stop?

Thanks for doing this!

3

@Peggy
Great questions. I’m in HV-battery development, so here’s what I know:

  1. BMS and balancing: Each cell is balanced, usually through passive balancing. Cells with higher energy are discharged using resistors to keep all cells in sync. Without balancing, one cell hitting 100% SOC would stop charging to avoid overcharging, even if others aren’t full yet.

  2. CAN bus usage: Depends on the manufacturer. You don’t need Ethernet for every system. CAN is still widely used where appropriate.

  3. Failures in testing: Can’t confirm or deny, but let’s just say testing can get interesting.

  4. Design headaches: Battery chemistry and aging behavior are new challenges. ICE systems don’t deal with these as much.

  5. Charger compatibility: In Europe, standards are still evolving, so compatibility can be hit or miss.

  6. Runaway motor safety: ISO 26262 standards play a big role. There are low-level devices, like fuses and relays, that can cut HV power if something goes wrong (e.g., overcurrent).

4

@Peggy
A lot of these answers depend on the manufacturer, platform, and vehicle. For example, throttle mapping will vary based on drivetrain (FWD, RWD, AWD) and torque vectoring, while CAN bus usage depends on whether the vehicle uses flat, domain, or zonal architecture.

5

@Peggy
I can answer two of these:

  1. Motor controllers: FOC is the core, but additional algorithms are used to manage second-order effects like vibration and temperature.

  2. Runaway motor prevention: The systems I’ve worked on include relays between the inverter and battery. These are controlled by separate processors as an added layer of safety.

6

@Peggy
I work on HV wiring and electronics for EVs. Here’s what I can share:

  • Motor control: EV motors are 3-phase, so frequency is key. Higher frequency = higher RPM.

  • Testing failures: Failures happen often in extreme conditions. Once, during a slow failure test, the wires became a fuse as expected.

  • Design challenges: EVs seem like they’d have more space, but that gets eaten up by cooling lines, refrigerant lines, etc. EVs are easier to manufacture, though, which is a bonus.

  • Charger compatibility: There are efforts to improve this, but it varies by OEM.

  • Safety features: HV batteries usually have main fuses, relays, and overcurrent protection to shut down power safely.

7

How did you land your job in the EV industry? I have a master’s in mechanical engineering focused on energy, but the best I’ve found is a basic technician role.

8

emma said:
How did you land your job in the EV industry? I have a master’s in mechanical engineering focused on energy, but the best I’ve found is a basic technician role.

I started in HVAC and got lucky. A distant connection at an EV startup got me an interview, and that got my foot in the door. Networking is crucial, though technical knowledge is still important once you’re in.

The best EV engineers I’ve worked with are adaptable and able to make smart compromises. It’s a tough industry because the tech is so new, but it’s fascinating.

9

@Nathan
Did you graduate around the 2008 financial crisis? I started in HVAC during that time too. Funny how many people ended up in the same boat, though most didn’t stick with ductwork forever.

10

Connie said:
@Nathan
Did you graduate around the 2008 financial crisis? I started in HVAC during that time too. Funny how many people ended up in the same boat, though most didn’t stick with ductwork forever.

It’s amazing to see where people end up. HVAC was a stepping stone for so many of us!

11

@Nathan
Being adaptable isn’t just for EV engineers—it applies to all engineers, really.

12

Mark said:
@Nathan
Being adaptable isn’t just for EV engineers—it applies to all engineers, really.

Absolutely! Engineering is all about flexibility and problem-solving.

13

Do EV manufacturers care about how much range drops in extreme cold or heat?

14

izael said:
Do EV manufacturers care about how much range drops in extreme cold or heat?

Yes, absolutely. In commercial EVs, we often design for specific use cases, which helps mitigate thermal issues. Battery thermal management is critical because operating in the wrong conditions can significantly reduce lifespan.

15

@Nathan
Range isn’t lost because the battery loses energy, but cold reduces voltage. Heat and cold affect performance, though.

16

Maria said:
@Nathan
Range isn’t lost because the battery loses energy, but cold reduces voltage. Heat and cold affect performance, though.

Correct. Cold affects electricity transfer and performance, while heat can degrade components faster.

17

@Howard
Exactly. It’s not capacity loss but reduced power output. Still, proper management is essential.

18

@Nathan
Thermal preconditioning is key to maintaining range in cold climates. Preheating batteries can drastically reduce range loss, even when using battery power to do it.