Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

DIY Home EV Charger

jamesfotherby.com

Post reply on HN
Print view View original

21–30 of 195 posts

Re: DIY Home EV Charger

#21

Post by finnjohnsen2 »

irjustin wrote: post #18
foobarian wrote: post #12

I'm disappointed at the anti-DIY sentiments here, it's this safety obsessed mentality that got us to where kids can't walk outside by themselves any longer. The box in that guy's build is outside and could probably burn to a crisp without hurting anything else. I suspect it would not hurt anything even inside a garage, other than making a lot of smoke and setting off smoke detectors.

> I'm disappointed at the anti-DIY sentiments here, it's this safety obsessed mentality that got us to where kids can't walk outside by themselves any longer. The leaps here are way too big.

and big leaps are certainly not safe

Re: DIY Home EV Charger

#22

Post by Kirby64 »

greenthrow wrote: post #8

This is such a bad DIY project because the costs of screwing up can be burning your house down. This is non-trivial amounts of power. If you spend the money fot an EV, buy something safe and have it professionally installed. Keep the DIY projects to something less dangerous.

TBH I’m less concerned about dangerousness… but the costs listed are so much, whereas commercial EVSEs are so cheap. You can buy a 40A 240V capable EVSE for like $200-300. The OP says they bought the cable for $120… why not just have the rest of it for a small additional cost?

Re: DIY Home EV Charger

#23

Post by Animats »

Geeek wrote: post #15
Animats wrote: post #11

1. Two words: strain relief. 2. If it's outdoors, at least spray the electronics with Fine-L-Kote or similar to keep water vapor out. 3. Those relays look undersized for the load. Look at Grainger for similar ratings. Do not buy power relays on eBay or Alibaba. Current ratings there tend to be wildly exaggerated. 4. Er, overcurrent protection? An approved circuit breaker?

Any Fine-L-Kote like recs that HD, Lowes carry?

That stuff has become much more expensive. $43/can on Digi-Key.

Re: DIY Home EV Charger

#24

Post by schiffern »

foobarian wrote: post #12

I'm disappointed at the anti-DIY sentiments here, it's this safety obsessed mentality that got us to where kids can't walk outside by themselves any longer. The box in that guy's build is outside and could probably burn to a crisp without hurting anything else. I suspect it would not hurt anything even inside a garage, other than making a lot of smoke and setting off smoke detectors.

  >I'm disappointed at the anti-DIY sentiment
How would you feel about a "DIY House Circuit Breakers" project?

This is essentially the equivalent. Total insanity.

Re: DIY Home EV Charger

#25

Post by newZWhoDis »

wannacboatmovie wrote: post #13
greenthrow wrote: post #8

This is such a bad DIY project because the costs of screwing up can be burning your house down. This is non-trivial amounts of power. If you spend the money fot an EV, buy something safe and have it professionally installed. Keep the DIY projects to something less dangerous.

Software engineers have a tendency to overestimate their own abilities, the arrogance is often on full display here for all to see. Maybe we need a few to burn their own houses down to act as a deterrent and encourage others to stay in their lane.

Some of us here are actually Engineers (Electrical).

I’ve installed 3x 240V 60A EV chargers, was a cakewalk. I didn’t build my own in this case since I was going for an aesthetic match.

Meanwhile you can enjoy paying some alcoholic $1000 for 30 minutes of work to:

* pop out a hole on the back

* Tap and install 2x screws into studs

* pull 3 wires 6” through, wrap around the strain relief, strip/insert/torque

* flip a breaker

It’s not rocket science, as long as you’re not a complete idiot and turn the breaker off before hand it’s completely safe. 240V isn’t even “high” voltage.

Re: DIY Home EV Charger

#26

Post by dreamcompiler »

eigenvalue wrote: post #9

More like a DIY arson investigation. You might not only burn down your house, but also get in trouble with the law and not receive compensation from your property insurance company. This is a horrendous idea. Just do basically anything else DIY besides high current/voltage electronics.

Page is hugged to death right now but I strongly disagree with parent. I'm an EE and I'm quite familiar with the National Electric Code. I build high current/voltage devices and I've wired two houses (both of which passed inspection).

If you're trained, experienced, and generally know what you're doing there's nothing wrong with working on high power electronics.

Re: DIY Home EV Charger

#27

Post by tw04 »

foobarian wrote: post #12

I'm disappointed at the anti-DIY sentiments here, it's this safety obsessed mentality that got us to where kids can't walk outside by themselves any longer. The box in that guy's build is outside and could probably burn to a crisp without hurting anything else. I suspect it would not hurt anything even inside a garage, other than making a lot of smoke and setting off smoke detectors.

>I'm disappointed at the anti-DIY sentiments here, it's this safety obsessed mentality that got us to where kids can't walk outside by themselves any longer.

Just no? That analogy is EXTREMELY strained. From his own link: A word about safety. I’m not an electrician. I’m not allowed to make alterations to my consumer unit.

I let my kids play outside all the time solo and with friends without supervision. On the flip side, I don't do things like design my own L2 charger because it violates several codes, would nullify my homeowners insurance, and could quite literally land me in prison should I mess it up and cause a licensed electrician to die because I did something dumb or cause my car to start on fire killing my family.

Do I do my own wiring? Absolutely.

Would I mess around with attaching something at 240v that I made from scratch that could burn my house down and kill my family if I do it wrong? Nope, I'm good.

Re: DIY Home EV Charger

#29

Post by shmoe »

newZWhoDis wrote: post #25
wannacboatmovie wrote: post #13

Earlier quoted context omitted.

Software engineers have a tendency to overestimate their own abilities, the arrogance is often on full display here for all to see. Maybe we need a few to burn their own houses down to act as a deterrent and encourage others to stay in their lane.

Some of us here are actually Engineers (Electrical). I’ve installed 3x 240V 60A EV chargers, was a cakewalk. I didn’t build my own in this case since I was going for an aesthetic match. Meanwhile you can enjoy paying some alcoholic $1000 for 30 minutes of work to: * pop out a hole on the back * Tap and install 2x screws into studs * pull 3 wires 6” through, wrap around the strain relief, strip/insert/torque * flip a…

You're 100% right, but it not being "high voltage" is totally negated by the fact that the two legs together will kill me if it seeks ground via the right (wrong?) path for sure.

Re: DIY Home EV Charger

#30

Post by elihu »

timthorn wrote: post #4
myself248 wrote: post #3

Save you a click: It's an EVSE, not a charger. Looks very similar to OpenEVSE but he wrote his own code. Nice clean build. Not sure why the extra work instead of just downloading OpenEVSE.

I'd have called an EVSE a charger - I might be naive but what's the distinction you're trying to make?

The terminology is kind of confusing, but usually the thing called a "charger" is the part that converts AC to DC at whatever voltage the pack requires.

For level 1 and 2 charging, the charger is in the car. J1772 ports are basically just fancy 110v or 220v AC plugs with some extra signalling.

DC charging tends to happen at much higher power levels, and that equipment is expensive so the AC-DC converter is kept outside of the car. The car itself just has a couple contactors (i.e. high power relays) to connect the charge port directly to the battery, and a microcontroller to tell the charger how much current it can handle at what voltage.

Post reply on HN