DIY Off-Grid Solar Power
mobile-solarpower.com
mobile-solarpower.com
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 think the internals are all pretty similar).
There are a couple surprise gotchas I didn’t know:
1) These Controller+Inverter combo units require a battery to turn on. This means: if your battery runs completely out of charge, you have to get electricity from somewhere to charge your battery a bit before the Controller+Inverter will turn on and charge your battery again. I was pretty annoyed at how not “off grid” this felt.
2) Temperatures below freezing are bad for batteries. I purchased a Renogy 48v smart battery with self heating. Unfortunately less sun in winter means less energy, and heat production is energy intensive. I’m not at the cabin 100% of the time so I have to take the battery with me when I leave to avoid spoiling/freezing it. Still not sure how I’ll ultimately get around this.
You can build a hole that will hold up to this sort of stuff for a while, but that tends to be expensive - underground concrete work is neither cheap nor easy, and given the number of people injured in trench collapses who do it for a living, a serious underground hole isn't a good DIY project either.
That just leaves the maintenance, which also sucks for a hole in the ground. Anything you have to do on the batteries is easier with them on or above the ground, instead of underground in a hole. For lithium, it's fairly low maintenance but you may have to replace some BMS boards every now and then, manually check balance, etc, and for lead it's water every few months, unless you go with sealed, which are "maintenance free," but also "maintenance and status check impossible," so you really just set them and run them to failure - you can't monitor condition like you can with flooded.
It's the sort of solution that, technically, would work - it just ends up being radically more expensive and a hassle than it's remotely worth. Think "Spending $5000 to save $20/yr" sort of thing.
You see the same trend with things like the complex solar trackers that were common in the 80s and early 90s. With the cost of panels, optimizing every bit of power from them was critical, so spending an awful lot of money on support infrastructure to optimize $10/W panel production made quite a bit of practical and financial sense.
Today, with panels at $0.50/W, very few people bother with trackers anymore (for off grid installs). Most things you could improve with a tracker, you can improve with less effort and less money by just hanging more panels. Bonus: With more panels, you get more production on cloudy days when panel orientation doesn't matter (because the sky is more or less evenly lit).
I've got south facing, east facing, and west facing panels on my office, of two different brands, all fed into a single MPPT charge controller input (I do have some blocking diodes to prevent backfeeding a shaded string, though). It's not nearly as "efficient" as some other options, but it's a whole lot cheaper, and gives me more power on the low cloud days that are the rough ones. The rest of the year, I have so much power out there that I'm demand limited, not supply limited (actually, inverter limited - if I added some 48VDC loads, I could use another 5kWh/day easily).
Get a plastic storage box, drill holes for cables and seal them with caulk. Put inside a treated lumber box for extra crushing resistance. Run cables through metal conduits to avoid mice and moles chewing on them.
Rent a backhoe, and you are done in half an afternoon.
All of that said, I dont know that I would actually go that far- you avoid the battery freezing, but then you get to worry about it cooking. For an off-grid cabin that isn't constantly heated in winter, it isn't the worst idea.
No issues so far, two years in. It’s not terribly cool in the hottest days of summer and does require a small heater if I want to keep it above freezing through winter, but in terms of being difficult or expensive to build, not at all.
Most people off grid have plenty of space but care about efficiency in terms of cost.
I know it’s only lighting as a load, but I’ve heard standard LED light bulbs will happily run as low as 36VDC, as they chop the voltage down to that level anyway.
It makes me wonder how many “120VAC” devices with switch mode power supplies could be plugged into 48VDC without any thought at all. And not just electronics like a laptop or non-plasma flatscreen, but everything is moving in this direction:
Like… what’s my Variable Frequency Drive “inverter” refrigerator motor voltage really running at? In theory it should happily run off 120VDC at least. Don’t do that, but somewhere under 110VDC should work fine. And it’s inherently soft start and easier on one’s low voltage wiring than an on/off duty cycle fridge.
Of course I recommend none of this officially.
Active power factor correction circuitry will have a fit, but... eh, whatever. It's DC now, nobody cares!
A 120VRMS AC signal peaks around 170V, and most (not all, but most...) switch mode power supplies are auto ranging, so they'll tolerate from about 100VRMS to about 250VRMS - which is near 400V peak. If you can get 300+VDC into them, they'll be quite happy, but the boost converters to do that are a pain to find, and by the time you build one, you may as well just get a 120VAC inverter and call it good.
The main thing to be concerned about, and the reason to jack the input voltages about as high as you can, is that almost every switch mode power supply has a full bridge rectifier on the input side. From an AC input source, each diode has a 50% duty cycle. Put DC on it, now two diodes are at 100% duty cycle, two are at 0% duty cycle. How much overhead was there in the system? Well... you'll find out! However, a system capable of running and not overloading the diodes at 50% duty cycle at ~100VAC should be totally fine in terms of diode heating at 300VDC - just, perhaps not at 100VDC.
All I could think about was the (potential) improvements on capacitor lifespan since they won’t have to smoothen, but wasn’t sure if their electrolyte could still heat/dry if it was actually the connection to power that makes them hot.
Thinking further, an internal fuse might blow with the (expectedly) larger current draw at 48V.
And yeah on input wiring, you’re pulling more current at 48V.
But as soon as you've got some stuff that requires an inverter, you may as well just light the inverter up for everything. I've got the equipment to do a separate, lithium-backed "DC rail" in my office that would be around 40V, and then buck it down for various devices, run my routers direct on it, and... I've never gotten around to doing it, because until literally everything is on that, I'd still have to run the inverter for things like system sleep (I sleep most of my computers overnight). I'm fiddling watts around and it's just not worth it unless I can actually shut the inverter down entirely. Unfortunately, boosting up to 300VDC isn't cheap or easy.
I've wondered if you could run some of that stuff straight off solar during good sun, but I've never really wanted to subject my computers to that sort of abuse.
That’s where I’m coming from: trying to convince a family member to setup a DC system so the inverter can stay in sleep mode during evening/overnight, because the efficiency is horrendous at small loads. it’s really academic in kWh savings per day, but it saves you the most when sunlight’s the least and reduces battery cycling. But if you’re running an office, the inverter is pretty much running a good load or off, I think.
If it's portable, your option works well.
For year round off grid use, there's something to be said for sealed lead acid, or flooded lead acid - they don't care about being cycled while cold (capacity is down and the voltage sags a good bit), and as long as they don't get too deeply discharged, they don't freeze.
A single panel, facing south, absolutely vertical, will shed snow and if you have no other loads, is usually enough to offset controller loads and self discharge over time to keep the batteries fully charged (and therefore not freezing) over winter.
There's no way you'll generate enough heat on electricity to keep a battery bank (or cabin) warm in the winter most places. I've got 5kW of panel on my office, and still can't manage that for a small, well insulated shed.
The amount of heat needing to be generated can then be calculated based on the average temp over a longer period of time, and those batteries I don't imagine have to be "warm" exactly.
It's good practice to snake a water pipe around every lithium cell anyway in big packs, because otherwise one bad cell can self-heat to the point of catching fire, even while other nearby cells are cold. The flowing water means the bad cell can't get to the point of fire.
Unless you live in the desert, having the batteries too hot isn't as big of an issue as freezing them.
Any charging around or below freezing causes pretty quick destruction of the cells as the chemistry switches to a more favorable destructive one way electroplating process instead of the desirable (and reversible) ion exchange process.
A common engineering solution to this has started to be temperature dependent shunts that route charging energy to heating pads around the battery until the battery temp gets above a certain safe point.
It adds complexity, cost, and adds several undesirable failure mode however, and Lithium battery cost is already a major factor in these systems, so if you’re in a situation where you can’t reliably temperature control your batteries (cold climate, non-conditioned battery space), lead acid is still a very viable and often desirable chemistry instead.
Round trip efficiency isn’t great with them, and you have to way over provision to get good cell lifespan, but it works.
Single purpose but not reliably there heat capture methods add cost and maintenance.
It’s often more cost effective to have a general purpose method that while not as efficient in one case is generally more overall (cost) efficient.
Sure, a backup plan is a good idea. But it doesn't have to be very good or very efficient, as it will be rarely used.
There are weeks with zero direct sun, just low cloud cover, scattered snow, and cold cold cold.
I was in Michigan once when Lake Superior froze over, shore to shore.
Unless the place is so well insulated you can keep it warm purely with body heat, you need supplemental heating in climates like this. The sun is not always shining.
Some folks in less severe climates (like New Hampshire) seemed to get by with baking and other managed appliance heat. That does require you spend time doing, and orient your activities around, things to produce heat to stay warm. Some will find that palatable, others won’t.
Posters in Colder climates (like Ontario) noted propane, or thermal mass heaters (such as the rocket heater in the thread).
‘Then the propane could make up the modest difference on long cold cloudy stretches.’
Thanks for linking it!
New ones do have a significant gain at that temperature. For instance this Samsung Nordic Home: https://www.elkjop.no/product/hjem-og-husholdning/oppvarming...
Solar panels produce the most power on cold winter days. The 'rated power' is for 20 degrees ambient at full (90 degrees, no cloud) incidence at sea level.
What you could say is that solar panels in the winter do not produce the same amount of power in an average day as they do in the summer due to the shorter day and the bigger chance of occlusion as well as the longer path the suns rays have to travel through the atmosphere.
I had 48KWh worth of storage, 2500 W worth of wind and another 5000 W worth of solar. This was in Northern Ontario. Until we added the windmill we fairly regularly needed the generator, after we added the windmill the generator just sat there gathering dust.
This was a major factor in designing the machine the way I did, variable pitch is a lot more work but a machine like that will start up far earlier than a fixed pitch machine. It also had its effect on that stator, which I made with the laminates at a slant over 1/3rd magnet width, which reduced cogging to nearly nothing. This is a huge factor in starting up a direct drive machine.
Insulation, too. A lot of sheds and cabins (and single-family homes) could do with more. Saves on cooling bills in the summer, too.
Anyway, in a cold climates like mine an acre would not be enough to keep you warm because trees grow slow when it's winter six months out of twelve. It takes a lot of wood to keep you warm, and one tree gives surprisingly little wood. After a handful of years you'll have clearcut your measly acre and still have another couple of decades to go before it becomes harvestable again. I'd say you want at least 10 acres if you manage it well and the soil and drainage are at least half decent.
They grow faster since they already have a root structure, the size is consistent and the wood is generally straigter (the japanese have a similar technique for extremely straight cedar logs)
It's old tech, it's boring, but it works fine... flooded lead acid. Don't fully discharge it in the winter, and they won't freeze. They'll cycle just fine in the cold. Well tested, proven, and unless you're full time living and heating an interior space that can be lithium-friendly, they're the right option. Disconnect all the loads and run them on float in the winter with a high, vertical, south facing panel (obviously swap that if you're in the southern hemisphere), and they'll do just fine.
https://docs.google.com/spreadsheets/d/1w8vPBHkMyY5jvkxtK1Qh...
Maybe even just toss them in an old discarded deep freeze? You could even have one battery in there that is disconnected from the rest of the system so it can be used to jump start the system if it ever gets fully discharged.
I think most people underestimate just how much delta in production there can be on solar. My house array is grid tied, 16kW, a bit weird looking (mostly east-west panels, designed for post net metering). On a really good, cool, clear, windy spring day, I can produce about 105kWh out of the system from sunup to sundown.
On a really bad, low, grey, winter day, that same system produces about 2kWh. It's literally a factor of 50 difference. And we can get several days of that in a row. I have a backup generator that I use for my office on weeks like that (separate, off-grid system).
"Winter, electric heat on solar" is a fairly good filter for those who have read about solar or pondered it, and those who have a few years of it under their belt. The second group are the ones who've tried it, discovered just how horribly it doesn't work, and are trying to convince the first group that, no, really, insert well worn idea here really doesn't fix the problems with it.
I guarantee if it were easy, people would be doing it. That you won't find any serious off grid system doing electric battery heating is because it doesn't work.
But, 2kWh or even less should be plenty to keep a well insulated battery compartment from freezing.
On very cold and clear winter days you are going to get more than that, and on cloudy days it is usually not that cold.
Maybe best to have them sit on a thick layer of insulation on the bottom, and a box that can be removed during the summer months so the batteries don't overheat.
Another a bit weird idea would be to somehow put them next to a compost heap, which produces low temperature heat for a long time (years) including during the winter.
I’d quite like a battery system, I think I’d DIY (well, design the system but here you need a licensed electrician to wire up the AC/grid connect side) using Victron equipment. I have a 5 kW solar system already with a AC inverter which I can keep, so I would probably use a 5000KVA inverter-charger (Multiplus-II), but then I’d add another 1.5kW or so of solar that is directly DC coupled to the batteries and the DC side of the inverter-charger through a separate DC MPPT tracker.
So the DC coupled solar would be enough to kick-start the system to get the AC side back on after a bit if the grid was out and the batteries were depleted overnight.
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.
Most of them don't operate that way. They need the battery bank connected first, and run off the battery bank side, while controlling the panel side.
Some may tolerate that sort of recovery from deep discharge, but it's not a safe bet, and some controllers are pretty clear that if you connect the input side before the batteries, you'll damage the controller.
A dumb PWM controller stands a better chance of doing this, but something like an MPPT controller, unless it's explicitly designed to fail into a PWM configuration at low battery voltage, won't - they need power to drive the buck converter circuitry (the controlling ICs and oscillators and such) in order to get power out of the panels.
bad for lithium batteries. even then, it is only bad if you charge or discharge them in freezing temps. lead-acid handle cold just fine.
What you need is more insulation. I've tested that battery and the internal heaters work great, but you should put it somewhere where the heat that is created stays in the battery.
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 long run."
That is just plain incorrect. Lead-acid batteries regularly last a decade or more and are far cheaper than any lithium option at a given capacity. Look at nearly every 12v car or boat battery. You don't see those being replaced every 3-5 years. It is old reliable tech that just works. And, at a given price point, they can charge faster than lithium too.
The downside of lead-acid? There is little profit to make in selling them. All the patents have expired. They don't need software to control them. They are mature, centuries-old technology. A thousand companies are making lead-acid batteries and you can get them cheap. They weigh more, but for residential installation that isn't an issue.
The upside? Whereas lithium packs are a nightmare to recycle, lead-acid batteries hook into an established and profitable recycling system. They are the greener alternative to anything containing lithium.
I actually do see this all of the time. In decades of owning multiple cars I've found the batteries tend to fail so regularly at about the 5 year mark that you could set a watch to it.
They are easy to find and inexpensive to replace, but they absolutely do have a limited lifespan.
I've never jumped a full EV, but I have had to jump a couple hybrids after their 12v batteries ran flat. Can you not get to the 12v battery using a mechanical key? Any 12v jumpstart kit should provide enough voltage to activate the solenoid and get everything online.
https://www.jdpower.com/cars/shopping-guides/how-to-recondit...
https://www.totalcardiagnostics.com/learn/recondition-car-ba...
And that’s why I asked - I honestly don’t know what steps are recommended to maintain a car battery (or if given the price it is worth the work).
Thanks for the links - I’ll look later
That's not to say they aren't filling their role in a totally reasonable way, I'm just really curious how you're getting more life out of them than the rest of us.
Deep-cycle batteries are commonly used as the house power for RVs, boats, solar storage, etc.
The only use case I've ever seen for lithium off-grid is for people who want to squeeze their entire rig into a closet or basement corner. And nobody ever talks about what to do with those batteries once they finally die. My packs will be easily recycled.
Volumetric density is a side benefit of lithium. We use it for coulombic efficiency, low voltage sag, high cycle life (much higher than lead acid, regardless of cycling bandwidth), usable capacity at low temperatures (much higher than lead acid! People always get this wrong), and higher specific energy. And lead acid sulfation and shorted cells require recycling. You can safely use a lifepo4 pack for years after degradation occurs. Lead acid is easier to recycle, but lithium ion recycling companies are dominating the space now. It is not like it was 3 years ago. Times are changing and there is no way anyone wants to throw out cobalt from a pack. LFP is much easier to recycle than cobalt based chemistries as well.
Which production lithium ion recycling companies are "dominating the space" and actually recycling more than test quantities of cells? Apparently I've missed that in the past few years - links to them?
The mid-range Trojan Solar Premium line (my office runs an older version of this, the T105-RE and I'm five years of daily cycling in with what seem to be entirely healthy batteries still) datasheet [0] shows a 3500 cycle life at 30% DoD, which is 10 years of daily cycling use. However, depending on loads, panels, and how you use the place, you'll typically see far shallower cycles in the spring/summer/fall, and then some deeper cycles in the winter months. So you can average it out - a single 80% discharge isn't going to have a huge impact on longevity, just don't do it all day, every day. If you've got enough panel area to recover a low battery bank in a good day or so of sun (generally recommended for off-grid), you'll have enough panel area to ride through daytime loads most of the year without really bothering the battery pack either.
The Solar Industrial line [1] is rated 3500 cycles at 50% DoD daily cycling, and about 6250 at 30% DoD. Good luck finding them, though.
They also, as has been discussed elsewhere here, don't need heating in the winter to be able to charge safely. I generally don't like charging lithium below about 45F, and even that would be a low C-rate. Not having to heat lead makes winter an awful lot easier.
As far as the rest of your claims... they mostly don't matter for a typical off-grid power system, which is the general context of this thread.
Coulombic efficiency for lead varies rather significantly depending on where in the state of charge, and it's not really reasonable to discuss "average" numbers for lead. Once you're full, up in absorb, the CE is quite poor, as it's gassing, but that's also required to mix the electrolyte and prevent stratification, so it's still doing something useful. However, the times when it matters - cold, dark winter months, if you're running partial state of charge cycling (which the modern carbon additives allow without the problems of hard sulfation), the CE during charging is quite good - near 100%, as long as you're below gassing. So when CE matters, when you're power limited, it's perfectly reasonable, and when it doesn't matter, when you have a surplus of power, it's poor. I don't particularly mind that.
As far as internal resistance goes, it's certainly far worse than lithium, but at typical off-grid C/20, C/8 type rates, it just doesn't matter that much. Nobody is asking deep cycle off grid lead to deliver starting amps for a tractor, and it won't do it, because it's a substantially different internal design than a starting battery (which have far lower internal resistance - go measure one sometime, it's pretty impressive just how low IR on a warm car battery is).
And my 48V/225Ah bank ran me $1400 about 5 years ago, and is about halfway through service life, or perhaps a bit less than half. To do that on a lithium chemistry would be quite a bit more expensive.
Plus, flooded lead acid lacks the energy density to do anything terribly exciting, as long as you give hydrogen generated from charging an "up and out" path. I consider this a feature for stationary storage.
And they're almost entirely recyclable (and actively recycled). It's a quite circular economy in the lead acid battery space.
Different chemistries have their places. For a somewhat overpaneled off-grid system in daily use, lead acid is still an absolutely reasonable chemistry (as quite a few people here are still observing).
[0]: https://www.trojanbattery.com/pdf/datasheets/SPRE_06_415_DS.... [1]: https://www.trojanbattery.com/pdf/datasheets/SIND_06_610_DS....
Please elaborate; I have no idea what you're talking about here.
My deep-cycle RV batteries are nearly dead and I'm going to spend the $$$ to replace them w/ a lithium battery partially because of lithium's faster charging. At peak solar season, I only get about 3 to 4 hours of good sunlight on my forested property so I need batteries that charge relatively quickly.
Lithium packs are not a nightmare to recycle anymore. There are huge corporations fighting to recycle them now, and the tech has improved a lot. I could not say this two years ago. Lead acid is easier to recycle, but the cycle life of those packs, and sulfation you have to deal with, make them horrible for the environment. Cycling them deeply kills them fast, even the expensive ones. If you do not cycle them deeply, FLA will last for decades, but will cost a lot of money , space etc. And you need to maintain them. Lithium ion chemistries such as LiFePO4 are far superior.
I think you need to get your hands on some cells and actually build a pack. Test the coulombic efficiency and usable capacity at various temperatures and you will be blown away. And you will save a ton of money over lead acid. Lead acid is very expensive, and I would make a lot more money if I sold them. I also do not sell anything on that website, it only has affiliate links. I am not on any sponsorship contracts or have loyalty to any company. Most of my review videos are me bashing design errors and various solar companies. I do not think you have seen my videos, going by your comment. It is a little bit cringy, unfortunately.
Yes, yes you do. All the time.
YouTube is simply the wrong medium to try to teach detailed, "can kill you" things like electricity. It's especially wrong when you try to make it about personality, humor, etc moreso than hard technical truths.
YouTube is literally just humans talking, so you are basically saying you don't think humans can teach complicated subjects?
YouTube is dominantly entertainment/personality based "edutainment" at best, based on what seems to percolate to the top and be promoted. There's zero feedback outside comments (standard warnings about comment sections apply here).
The right way to teach complex subjects is a more interactive process with hands on material/learning/actually solving the problems yourself. In the case of solar and energy systems, you can do this, but if you don't have some basic EE background, it would be wise to go get that first before listening to some slick talking huckster selling their wares. WHY do we size wires the way we do (either for temperature limits or for voltage drop, depending on the application)? What's wrong with a 5000W 12V inverter (500A or so, and the I^2 components of resistive losses, paired with the voltage drop from those)?
I don't think a human lecturing blindly into the void optimizing for "engagement" (whatever metrics those are based on this week) can competently teach any real detailed material, no. That doesn't mean that people can't teach complex material. It just means YouTube is not the place or medium for it.
1. A theoretical space for someone with good ideas and good intentions to share those with the world.
2. The actual experience that viewers will have on YouTube if they were to open it today.
1. and 2. would be almost diametrically opposed these days. If YouTube provided ways for viewers to honestly and fairly discover, rate, filter, and share videos and channels, then the people in case 2 would be able to reliably find the people in case 1. And if YouTube didn't force video makers to pervert their personality and format into algorithm-pleasing parodies, then people in case 1. could continue to produce the content they actually want to produce as long as they were able to. But it's not possible today.
I've yet to see a "YouTube Trained" pack build that I would be remotely comfortable leaving unattended in my house. Though LFP is an awful lot more forgiving than a mix of random recycled 18650s of unknown chemistry, service life, and internal damage history that makes up the bulk of that stuff.
If you've got some good high res shots of the build process, I'd happily take a look and see what I think of it. My standards of comparison are the professionally built packs I've torn down for analysis and often enough rebuilt for people.
As for who my comment is about, honestly, I apply it generally to that entire class of person on YouTube no matter who they are. I know solar, and off grid solar, fairly well (with a focus on flooded lead acid). I know lithium fairly well, having done quite extensive work on them. In areas I know well, most of the people showing stuff off or trying to teach other people hit the 90/10 split, and as this is a topic of conversation in the quiet off grid backwaters circles I frequent, other people usually agree about which 10% is the problem.
Therefore I'm happy to ignore that entire class of person and go do something useful. It's not that education can't be funny, it's that when "personality" and "laughs" and "BIG O FACE I NEARLY BLEW MYSELF UP" style thumbnails are what matters, the really deep (and often quite important) technical details get lost in all that.
He's the kind of Youtuber that keeps repeating that you should place a low temp sensor on your cells, not the kind doing sketchy spot weld on old 18650s.
Have you spent any time watching Will's videos? Your quote doesn't match up at all with what I've seen at all. I found his videos dry, technical, and pretty good with regard to safety.
Yet I still make this choice because the alternative is a "John Deer no right to repair" future where we're ruled by chuckeducks and awful people who can't help but quote "rules and regulations" or can't wait to be up in everyone's shit. There is no way I could be convinced otherwise because this is the nature of those who fiddle and tinker in the first place. I'm sure many of the viewers on this channel think likewise because it's not about safety but about my own freedom to spend my weekends in the garage building something and being rewarded with self reliance. And also the freedom to make mistakes big enough to kill myself by accident without somebody going "uhm well ack-shually".
The problem with Lithium Ion installations of any size is that the batteries are inherently dangerous and mistakes can easily set you back more than you saved on the whole thing. Unlike say your car where as long as you stay away from suspension, brakes and steering the worst that could happen is that you end up stranded by the road side.
Another issue is that when it goes wrong with Lithium Ion it can go wrong fast and it isn't easy, or sometimes even possible, to stop a thermal runaway once it gets going, especially with densely packed cells, besides the fact that you likely won't be watching your batteries 24x7.
There are some people on youtube that advocate for extremely unsafe practices (Jehu Garcia, for instance) and that have a huge following, so Will Prowse is certainly not the worst that you could run into there. It would also be good if he indicated more clearly what his sponsorship relations are and how that relates to the advice that he is giving, quite a few of his videos feel like thinly disguised ads.
He had a couple of sponsored videos in the past around building all in one systems, but it's not something he does anymore.
My objection is with people learning it from YouTube, because the ratio of "good, safe, correct information" to "absolute crap" is horrible, and until you're quite solid in the field, there are people very confidently spouting exceedingly wrong and dangerous information (tip: If you ever see anyone soldering to an 18650, assume everything else they're doing is wrong as well, because that's such a huge violation of every manufacturer datasheet - it dumps radically more thermal energy into the cell and plastic separator than they're designed for).
There are plenty of better sources for information on how to do things energy related than YouTube.
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 and edited video:
https://www.youtube.com/channel/UC0pBauLp63yzf6sVdEOIUbA
If you want to learn about DIY off grid power from youtube I'd start here.
That's hopeful, with that kind of following he has some serious responsibility. At the same time, I cringe when I see people working with large packs on workbenches with loose metal laying around, totally irresponsible pack geometries where balance wires cross and recross each other with abandon, recycled cells that have visible external damage and so on. Youtube is a great way to pick up some 'worst practices' thinking that if these youtube stars are doing it it must be ok.
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.
And thank you. Just figured out the automated banning process and am using a VPN now. I just want to respond to people, and I hope they can provide evidence of when I did something dangerous. Or said something wrong. And yes, I see what you mean about the downvotes. I am very upset right now because I could argue every point made against me here. I also allow people to criticize whatever they wish on my forum, so it makes it hard on this site where I am instantly censored if I get downvotes. It is very frustrating.
E.g. you can't downvotes responses to your own comment. This to steer into a different type of conversation.
I can't say I've fully internalized it, but it does make for much less shitposting compared to reddit.
The downvotes i don't think are due to disagreement or even anger.
I understand your frustration (especially since the critique is so unspecific), but i believe the downvotes don't mean what you think they mean, and it's not personal.
https://www.mobile-solarpower.com/diy-beginner-friendly-sola...
Is going to bolster your reputation as safety conscious or harm it, besides your general attitude in this thread. You are quite clearly advising people to copy this design, you make money of them doing so. Even a one-off should be better designed, let alone something intended for duplication.
I had you down as well meaning but a bit out of your depth at times, let's just say that that didn't improve based on the interaction here and your various comments.
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 everything before putting it out there to ensure that the net result is a positive one.
Also: I don't like the youtube format for stuff like this. It would be far better to have these things as blog posts rather than as videos, that would make them much more searchable and easier to annotate.
But just to give you two memorable items: at some point Will shows himself working with naked steel tools on a massive, fully charged, unfused battery pack. Just one wrong move or a dropped tool and the carnage would be substantial. That shows to me that he may have good theoretical knowledge but doesn't really know all that much about working with this stuff in practice and how to do so safely. In another video there is a whole slew of balance wires coming out of a pack, crossing and recrossing with abandon. Balance wires are usually not fused, the wires rubbing means that if that installation were for long term use that eventually the balance wires would short out and if you're lucky it would just result in a balance wire evaporating, if you're unlucky it would start a fire right next to a massive Li Ion battery, something that you really don't want to do because of their thermal sensitivity. The risk is that the whole pack would ignite and good luck putting that out.
I went to the ETS in Amsterdam, a school for electrical technicians, mid level. The one thing that was drilled into us over and over again during the practical parts of that education is that in the electrical world there are young safe technicians and young sloppy technicians, but there are no old sloppy technicians.
Will is still young.
For what it's worth if you are the Will Prowse from Youtube I do appreciate the videos you make. Your channel has exposed me to companies I didn't know existed. The Hysolis tear-down was interesting and saves me from having to take things apart and risk warranty arguments with the vendor. There are some shady vendors making bold claims and it is nice to see which ones are the real deal.
Thank you!! Hysolis is awesome, and with the LF inverter, you can easily work on it yourself. I am glad my videos help :) There are tons of scams online these days, and I love exposing them.
Please keep up the great work. That is a very worthy battle and will save people a lot of frustration and money.
I plan to get 3 of the Hysolis portable units. Last I checked they didn't have the external battery available as an option yet so I've been holding out. I'm also hoping they have custom shipping options because Amazon uses UPS and they track snow into their trucks which isn't great for electronics. That inverter is heavy so it will be on the floor of the truck for sure.
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 pack where I was testing something. I know what I'm doing and how it works. 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? 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? Give me a break
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.
And yes, I hope people follow my advice more than the other channels. People on this website are suggesting people use cobalt based chemistries that have dangerous thermal runaway reactions, from recycled products, which is dangerous. And then my channel complains constantly on the importance of low temp charging disconnect, OCPD, high voltage and so much more. What am I doing wrong here? How you read my comment, makes me realize that you never did watch my videos. You really have no clue what you are talking about. Using recycled NMC cells will burn your house down, plain and simple. And people in this group who think they know what they are talking about are recommending to do that instead? What???
Yes, with authority comes responsibility, and the only reason people follow me is because I cover every single detail, and I substantiate my claims with relevant literature in the lithium ion space.
What unsafe practices!?
Similar, but I would _never_ play fast and loose around batteries of those sizes just because I felt like I won't make "silly mistakes". Everyone, even professionals who have been doing dangerous work for decades, make silly mistakes. That's why professionals don't fuck around. One wrong move with large lithium cells and you've got a massive jet of fire in your workshop that can't be put out.
Similarly, I'm a woodworker and while I feel like I know what I'm doing around a table saw these days, I _always_ make sure to have my adrenaline pumping when making cuts. I Point and Call my safety checklist every single time. I wear my safety glasses for even the simplest cuts off the table saw. And guess what? It has saved my bacon. It's the simple, mundane, "I don't make silly mistakes" days that cost you.
> And wow you're so dramatic
It's better etiquette to address the content of a comment rather than lob insults against the commenter. The former is less argumentative and can be more informative. Strive to enlighten and inform. Nobody learns anything useful from phrases like "you're so dramatic", "Give me a break", "you are giving me a hard time", "Are you kidding me?", "You have no clue what you are talking about", etc.
My opinion of him after his attempts to interact in this thread (turn "show dead" on - a bunch of his more arrogant/abrasive posts have been killed, and it looks like he's posting as Solar2 as well) is now far, far lower than it was.
I recently built a LiFePO4 battery and upgraded our caravan (trailer) electrical system following these guides and with help from the forum. Couldn't have done it without those resources.
https://www.youtube.com/watch?v=JQa5gn-7D74
He also has setups with used laptop batteries.
I'm also working on a way to bring power in from my alternator but unfortunately I think I'm going to have to invert in the engine bay and rectify feeding into my MPPT controller to avoid running some absurdly thicc wire to carry a few hundred watts at 12 volts.
The on grid part helps with credit banking during summer and using in winters. For that, I changed my on grid inverter with a "phocos solar inverter" that does the same thing but also, when there is a grid power outage, it still supplies power to home without having batteries.
I haven't bought batteries because of the cost but this has been a good experience.
My panels are 16*325W and I produce around 30Kwh during the day in summers and during the current winter, I get enough to run appliances, rice cooker and lighting.
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?
Perhaps it makes sense to have a chat with Solar Team Eindhoven/Twente/Delft? Or have a chat with the people at Lightyear. They have a lot of former teammembers.
I am building an off grid / backup solar install for a house in rural Romania. I want it to be off grid capable, but also be able to use the grid when available.
One thing I am curious about: do the all in one systems like Growatt or MPT also provide voltage stabilization? The grid here has really bad voltage stability.
Sometimes the voltage drops down to 180V (should be 220V in Europe). Some devices like LED lightbulbs and washing machines don't like this at all.
So if these devices provide voltage stabilization, that would be great. I would then buy one and a few batteries, and later add the PV panels. It is going to be about 12kW of roof integrated PV.
I would suggest that you add solar with a small battery bank and use the grid for overnight and for dark day charging. This way you have the best of both worlds as you only need a big battery bank if you need a lot of power when there is no sun.
P.S. Start with a 48 system since you are going for so much solar power. It is safer and cheaper in the long run.
Maybe charge the batteries from either the grid or the PV panels, and always run the house off the batteries via a separate inverter. That way, you got the inefficiency of AC->DC->AC but always have stable voltage.
In the long run I want this to be mostly off grid anyway, with the grid as just an emergency option...
There is so much tree cover all the time. Some days, even though it's mostly or fully sunny, we're almost always at the end of some disused fire road on the wrong side of a mountain, and we're lucky to get a couple of % back from all-day charges. I'm considering one of those water-powered turbines, since it'll work all night long as well.
Are you able to tilt your solar panels? If they are lying flat on your roof, you won't get much power from them.
Speaking as someone that has spent the last three summers off-grid in a forest, in your situation, I'd add the ability to tilt the solar panels, reduce power consumption, and get a multi-fuel (propane and gas) inverter generator along with a propane tank. The inverter generator is a lot quieter, smaller, and lighter than generators. I don't need much power and mostly use the generator for the microwave and occasional topping off the batteries.
Far too many solar installers just treat a system as the entry to people coming back for more, when the problem is that they don't know enough to adjust it properly for the stuff that was installed in the first place.
[0]: https://handybobsolar.wordpress.com/
//EDIT: So, apparently, a site that's been static since 2011 and I've linked quite a lot over the years was updated again in 2020 with some ranting about Covid. You can safely ignore that, and read his older writings on solar installs, because just about everything he says about that is correct, at a "Spend five years hands on with solar and you'll eventually come to agree with him, no matter how loony he sounds about some of it when you start in."
Also, you'd be surprised how little energy you actually use out there. A quality fridge-freezer like an Engel or ARB can be run for days before it will discharge the battery in a parked truck enough to not turn the starter. This scenario pretty much never happens, so get a good battery, a good fridge, and you'll be fine.
It is an interesting feeling when you are truly bugging out or off the grid, almost a primal kind of thing, because instances where self reliance is the only thing left is becoming less and less of an occurrence. If you ever go camping in the wilderness by yourself and set in for the night alone, you probably know the feeling!
Another similarly remote place is the Arizona Strip, the portion of the state that lies north of the Grand Canyon. You access it from Utah and it's 95 miles from the outskirts of Hurricane, UT to SB Point, above the canyon.
Generally, we stay out for about a week and half and come in to town every 2-3 days, mostly for gas. We run Engel fridge/freezers, which give you essentially unlimited cold drinks and the only real limitation is space for fresh food.
Where can I find such information to build a hybrid energy solution?
Solar will be consumed in priority. If there's too much it will be sold and if there's some missing il will be automatically (by the laws of physics) imported from the grid.