DIY Home EV Charger • Hacker News Board

Re: DIY Home EV Charger

#191

Post by shiroiuma » Wed, Dec 06, 2023, 2:23 AM UTC

sowbug wrote: post #190

shiroiuma wrote: post #67

Earlier quoted context omitted.

I don't think this is a valid comparison. In DIY projects, your time is free: you don't count your engineering hourly rate as part of the cost of building the thing. The only cost is the actual costs incurred, which is mainly parts and materials. So a Show HN project that's purely software effectively is worth $0, because the creator made it in their free time, instead of spending that time playing video games or wat…

When I was 20 years old, I would have agreed with your position. But that was a long time ago. Everyone, no matter how materially wealthy they are, gets 24 hours per day. That time is, by definition, 100% of the time that you'll get, which means that its value (intrinsic) is nearly infinite. This is true even if its price (extrinsic) is zero. My point in mentioning an engineering rate was not to quibble about what fr…

I'm not sure I follow. My criticism is in trying to value projects in term of engineering time. I don't think that's valid at all. Free time is worthless, except to the person spending it. It's not like I'm going to spend my free time doing more work for my company and make that much more money at an hourly rate: I'm salaried, so extra time spent is just a gift to the company with the vague hope I'll get some bonus or promotion. Plus, for mental health I have to take breaks from work and do something different, which could be reading a book, watching a movie, or working on a personal project completely unrelated to work. Either way, I'm not counting that time in terms of an hourly rate; I think that whole concept is just insane. I don't think of the time I spend on the toilet or making dinner in terms of an hourly pay rate, so why would I do that for a personal project? The only cost to me to pursue a hobby is in the materials needed.

Re: DIY Home EV Charger

#192

Post by sowbug » Wed, Dec 06, 2023, 3:49 AM UTC

shiroiuma wrote: post #191

sowbug wrote: post #190

Earlier quoted context omitted.

When I was 20 years old, I would have agreed with your position. But that was a long time ago. Everyone, no matter how materially wealthy they are, gets 24 hours per day. That time is, by definition, 100% of the time that you'll get, which means that its value (intrinsic) is nearly infinite. This is true even if its price (extrinsic) is zero. My point in mentioning an engineering rate was not to quibble about what fr…

I'm not sure I follow. My criticism is in trying to value projects in term of engineering time. I don't think that's valid at all. Free time is worthless, except to the person spending it. It's not like I'm going to spend my free time doing more work for my company and make that much more money at an hourly rate: I'm salaried, so extra time spent is just a gift to the company with the vague hope I'll get some bonus o…

My mistake was using typical prices for engineering work as an attempt to establish a baseline understanding that we all agree free time is very valuable. I can see how that's become a morass in this discussion.

I value my own free time much more highly than I do my employment time. I would prefer to have more free time than employment time. So if employment time's going rate is $X, then a dollar value of free time must be higher than $X. No, I don't expect people to pay me for my free time. But I do think it's healthy to think of free time as the most valuable time someone can have. Not the highest price but the highest value.

This is why I think it's wonderful to see projects on HN where we find out how our fellow geeks are spending their most valuable time. And it bugs me that people sometimes respond that someone could have bought the same thing for less money or less time.

Ironically, we both object to putting a price on time, but I believe our objections are in opposition to each other.

Re: DIY Home EV Charger

#193

Post by shiroiuma » Wed, Dec 06, 2023, 8:38 AM UTC

sowbug wrote: post #192

shiroiuma wrote: post #191

Earlier quoted context omitted.

I'm not sure I follow. My criticism is in trying to value projects in term of engineering time. I don't think that's valid at all. Free time is worthless, except to the person spending it. It's not like I'm going to spend my free time doing more work for my company and make that much more money at an hourly rate: I'm salaried, so extra time spent is just a gift to the company with the vague hope I'll get some bonus o…

My mistake was using typical prices for engineering work as an attempt to establish a baseline understanding that we all agree free time is very valuable. I can see how that's become a morass in this discussion. I value my own free time much more highly than I do my employment time. I would prefer to have more free time than employment time. So if employment time's going rate is $X, then a dollar value of free time m…

Yeah, I think we're agreeing but in different ways. I think of my free time as mostly worthless to others, but infinitely valuable to myself, so I refuse to put a dollar value on it.

And sure, I agree that it's nice to see people spending their most valuable time doing something they enjoy, in this case interesting projects.

But as I've said elsewhere, personally, I wouldn't spend my time making a copy of something I can just buy a better version of cheaply elsewhere; if I'm going to spend my time on a project, I'd rather spend my time doing something different, like something new or a customized version of something, which I can't easily buy. But it's not black and white; I'll happily spend my time fixing my bike instead of paying someone to do it, for instance. (Of course, paying a professional might take more time once you consider how long it takes to bring the bike to them, and then wait a week for them to get to it...) I like fixing things like that, so for me it's enjoyable.

Re: DIY Home EV Charger

#194

Post by NotSammyHagar » Wed, Dec 13, 2023, 12:09 AM UTC

NotSammyHagar wrote: post #84

oceanplexian wrote: post #80

Level 2 chargers aren’t actually chargers, they just pass mains voltage and some signaling. The charger is inside the vehicle.

The evse (misnamed charger here) needs to reduce the amperage based on what the car side wants. So it does more than just pass mains voltage.

Sorry, I was wrong about this. Too late for me to edit my original posting.

Re: DIY Home EV Charger

#195

Post by sib » Thu, Dec 14, 2023, 10:43 PM UTC

balls187 wrote: post #79

sib wrote: post #42

Earlier quoted context omitted.

Well, there are times when you're not charging overnight (e.g., get home with low battery, realize you only have 3 hours before next outing) and you get 50% more charging done in the same time, without having to go out to a Supercharger / DCFC. Or, as in our case, we have two EVs - speed is useful sometimes.

So you installed 2 60A circuits?

Actually one 60A and one 40A. We have a 100A subpanel in our garage. Having them asymmetric (vs 2 x 50A) means that if we need one specific car to be charged as fast as possible, we can.