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DIY Off-Grid Solar Power

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161–170 of 234 posts

Re: DIY Off-Grid Solar Power

#161

Earlier quoted context omitted.

Yeah, lead wins hands down. This is a few years out of date now, but when speccing out my system I did a bit of analysis of battery types. We went with OPzS, and so far, so good. https://docs.google.com/spreadsheets/d/1w8vPBHkMyY5jvkxtK1Qh...

Recycled Lithium Ion is much cheaper still, but more risky (and less maintenance). You'll have to do some pretty fanatic inbound QA to determine whether all your cells are safe to use. but if you do that and fuse your cells individually you should be able to make that work.

but still main problem is subzero temperatures. recycled lipo batteries do not become immune to this problem.

Re: DIY Off-Grid Solar Power

#162

Earlier quoted context omitted.

I have seen enough of his videos to know that he can be spectacularly wrong (dangerously so) about some of his stuff and if you are not already very knowledgeable about this then you may well end up following some very bad advice. This guy has far more practical experience and seems to be less error prone, and also does not shy away from showing when he gets it wrong, which is often far more valuable than a polished…

Quoted post unavailable.

The comment despite having some useful sentences, is too confrontational for this site and someone flagged it. I would love to see substantial comments from you here. Check the guidelines linked at the bottom of the page.

Re: DIY Off-Grid Solar Power

#163

Earlier quoted context omitted.

I can't recall particular instances but I've seen the same before. FWIW he's getting less stuff wrong over time.

Like what?! Can't any of you people backup your claims. It's just empty complaining on this site without evidence. It's driving me nuts. Show me what I said or have done that was wrong.

Mate, I've been following you for a while and have a generally positive opinion of you. I think you're not going to have a good experience coming here with your guns out. I watch all your videos, but wouldn't I be a fool if I just absorbed what you say as gospel? You don't do this yourself, don't you?

I'm happy for you and your success and I'm very happy there are people out there like you changing their life outcome out of sheer will, while providing the community with unbiased product reviews and independent tests.

Please don't take the criticism as a personal attack. Unfortunately, I just don't recall which information you said at some point that made me cringe. Like I said, I've watched a lot of your videos and haven't had any cringe moments like this for a while now.

EDIT: also fyi, this website has an automated banning process if you're a new account with too many downvotes. Unfortunately, the few messages you've written have a confrontational tone that usually attracts a lot of downvotes. If you care at all, may I suggest that you avoid that tone/style. I'd love if you posted here in the future. Take that as you will.

Re: DIY Off-Grid Solar Power

#165
post #8

I recently set up my own off grid solar system in a tiny cabin that I designed and had built. I used the Solar Controller+Inverter Combos recommended on this site (Growatt) but ultimately switched to ones by Renogy. The Growatt one I purchased has a wifi adapter and app - wifi requirement was a deal breaker when remote. The renogy one has a Bluetooth adapter and app, plus feels better designed (though actually I thin…

>> 1) These Controller+Inverter combo units require a battery to turn on

Which is why you want to install disconnects between your battery bank and the electronics. In a worst-case scenario of total discharge you can then bypass the dead batteries, hook the control electronics up to car batteries if necessary (be careful about voltages) and perform some diagnostics or at least read the logs of what went wrong. But the controller+inverter should be running if supplied with voltage from solar/wind/generator regardless of how the batteries are doing.

Re: DIY Off-Grid Solar Power

#166

Earlier quoted context omitted.

Sure, but I will have to go through a couple of months worth of youtube history, I was binge watching anything about Lithium Ion when I was working on this: https://jacquesmattheij.com/long-range-ebike/ As a result I have a very long article on Lithium Ion battery safety and pack construction in the works, but exactly for the reasons the GGP lists I'm pretty careful about releasing that, I want to triple check everyt…

Just because I am young doesn't mean anything. I know what I'm talking about. I started coding and building robots when I was 13, and circuit design at 15. Solar power is dead simple. Yeah I can work with raw terminals because I don't make silly mistakes. I've been working with low voltage DC for decades. Most of the systems I throw together are for educational use. Those balance wires were probably a rapid prototype…

> Yeah I can work with raw terminals because I don't make silly mistakes.

This attitude will cost you dearly and is exactly the difference between being a responsible educator and someone who probably should pause to ask themselves if they are on the right track.

You are setting a bad example and many thousands of people will follow in your tracks adopting your very unsafe practices as though that's the way to do it. Some of them will end up hurt.

It pretty much validates my earlier assessment but I'm actually a bit surprised that you would come out to make it so obvious.

> Those balance wires were probably a rapid prototype pack where I was testing something.

Yes, but that's not what matters here. What matters here is that people see you work and believe that's the way it's done. With authority comes responsibility.

> And wow you're so dramatic about the balance wires why don't you criticize the companies that offer their pack configurations in ways that you complain about?

That's whataboutism. We're discussing you, not some company. These tricks don't really work on HN.

> There are many companies that throw these packs together and sell them to unsuspecting people, and you are giving me a hard time when making a quick pack to educate or test something?

Yes, I'm giving you a hard time because you are at the same time claiming to be educating and you are advocating unsafe practices while doing so.

> Give me a break

Unlikely, and after this comment far less so.

But thank you for clearing up any ambiguity about where your feeling about responsibility lies.

Re: DIY Off-Grid Solar Power

#167

Earlier quoted context omitted.

Recycled Lithium Ion is much cheaper still, but more risky (and less maintenance). You'll have to do some pretty fanatic inbound QA to determine whether all your cells are safe to use. but if you do that and fuse your cells individually you should be able to make that work.

but still main problem is subzero temperatures. recycled lipo batteries do not become immune to this problem.

That is very true, especially at charge time you want to make sure your batteries are not too cold.

Re: DIY Off-Grid Solar Power

#168

Together with my girlfriend I’m planning a trip. Driving from the Netherlands to South Africa and back with an EV. We want to charge the car with solar panels we bring with us. See our website for more details: www.4x4electric.com Challenge for now: how to charge the car with ~60m2 of flexible solar panels. We need a threephase offgrid solar system, but did not find a suitable solution yet. Any ideas?

Wow, that sounds like quite the adventure. Have a 'plan B' in place in case your gear gets damaged or stolen.

Re: DIY Off-Grid Solar Power

#169

Marketing. I would take everything on this website with a grain of salt. Take it from someone who has actually built an off-grid system, one that is relied upon for 24/7/365 living rather than mere vacation cottage. For example: OP re lead-acid battery options: "Heavy, cheap, easy to use and they work! Typically will last about 3-5 years. Slower charge rates than lithium, much heavier, and they cost way more in the l…

I can believe that lead-acid batteries in a thermally-regulated and immobile location would have a longevity advantage. But what magic dance are you doing to get car batteries to last longer than 5 years? I - and my parents, and seemingly everyone else I know - absolutely do seem to have to replace them at just about exactly that interval. That's not to say they aren't filling their role in a totally reasonable way,…

Invest in a good trickle charger/maintainer/desulfurer (100-150$) and use it occasionally, especially if the car is going to sit for more than a week.

Re: DIY Off-Grid Solar Power

#170

Marketing. I would take everything on this website with a grain of salt. Take it from someone who has actually built an off-grid system, one that is relied upon for 24/7/365 living rather than mere vacation cottage. For example: OP re lead-acid battery options: "Heavy, cheap, easy to use and they work! Typically will last about 3-5 years. Slower charge rates than lithium, much heavier, and they cost way more in the l…

That's interesting. Winters are cold where I'm originally from, and car batteries get replaced more frequently than once in 10 years. Where are you from? Your experience is very different.

Northern Alberta. Currently -30c. The 8yo battery in my car started my engine just fine this morning, with the help of my block and battery heaters that ran all night. I think people in the north might have longer battery life because of the harsh conditions. We probably spend more time/money on maintenance of vehicles precisely because we need them to start when very cold. I have noticed a deeper voltage drop when starting my car this winter. The battery might well be on its last legs but so long as it is still working I'll hold off replacing it. (I do carry a jumpstart kit in my trunk, right beside the snow chains.)
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