Essentially, pic-related is everything I need to know, but I'd like to talk about it anyways.How can I keep it legal? (I'm in Germoney, so I can only do a "Balkonkraftwerk" without involving the power company, meaning I can at max have 800W flowing into the grid. Of course, I'd rather not have anything flowing into the grid, using it all myself, so that means batteries, but that is either expensive, or I'm not sure if my electrians-skills are good enough for that.tl;dr:What do you have on your roof and how did you put it up there?
>>2903345>I'd rather not have anything flowing into the gridThat's not always desirable since, solar panels being cheap, you'd usually want to oversize the system - provided you're not limited on space. Conversely batteries being somewhat expensive, you usually wouldn't want to buy a battery big enough to store enormous amounts of excess.I saw someone posting a $1k-ish literal balcony setup sold in Germany with a "solar generator" managing everything, and for that price, and being plug&play, it was a decent deal. Total /diy/ of a battery is not hard at all, but it is very dangerous to fuck up. In current year and current market, buying a complete battery parts kit with everything except cells, including a JK-BMS, and then plopping in 280-300Ah A-grade cells from nkon would be the way to go.>What do you have on your roof and how did you put it up there?~5kWp in 410Wp cells all roof mounted, had a company do a complete install. Will be semi/diy/ expanding by another 8kWp this year on another roof, plus in a different location doing a full /diy/ install for a ~4kWp initial set, possibly ground mount, and another 4kWp roof mount later.
>>2903345>What do you have on your roof and how did you put it up there?Some panels, screws
>>2903345what do you guys recommend to affixing solar panels to the ground? currently i am in the process of buying a terrain next to mine and i need to put temporarily the panels in the fence between our terrains, upper side in the fence, the other in the ground. I dont want to do anything permanent, as i hope it wont be there for more than a year.would camping stakes be a good idea?
>>2903700I haven't used ground screws, but they seem fairly easy to install and remove. Alternatively find some bricks or concrete blocks and do weighed panels.
>>2903345>What do you have on your roof and how did you put it up there?Am i doing it right?Only two on the actual roof, however a quick count has 50 of various sizes attached to the building. >Idiot has those two on the side The two 100w panels on the side are to boost the system in the winter, on clear days they put out around 50% more than the two identical ones on the pivoting mount when it is pointed perfectly at the sun. Reflected light from the snow makes them better than ones that are angled 'right'
>>2903711Same guy. Full baka off grid lit up like Christmas tips:>Whenever possible use independent systems for the lights, solar barn/security lights ect>Get cheap solar yard lights from end of season sales at dollar stores or yard sales, like $0.50-0.25 each>But those suck and the ones from yard sales all have dead batteries!>Which is why you replace the Ni-Cds with bulk Amazon Lithiums>Yard sale barn/security light doesn't work because of dead battery?>Buy all the 'dead' power tools at the yard sale or scrounge 'dead' tool batteries from people you know, at least half of them have perfectly fine 18650s in them the charging circuit board is fried
>>2903569It was absolutely pissing it down all day and got a pretty poor result out of it.The bank was also precharged to ~90% but this didn't fill it so I'm not sure what is going on there
Also I wanted to know if anyone has experience with copper tube bus bars?For the charger wiring I just shoved 2AWG wire in the open tube and smashed the thing with plyers to crimp it.Should I solder it? I have strong concern that it is not a good enough connection for 100 amps.I am also aware that running this many batteries in parallel is dangerous, I don't give a shit.
>>2903711I'd almost guess it's Wayne's, except the house itself looks too decent for that.>>2903796All of these connections have to be crimped properly, buy a hydraulic crimper off chinks. I don't think paralleling the batteries is bad if they're lithium, maybe more so if they're not. You should definitely unfuck the connectors and definitely cover up at least one of the bus bars, so that the first wrench you drop on it doesn't immediately do a dead short on a 1000Ah battery.
>>2903345The solar batteries are easy man. I'm retarded and built my own 280ah, you can easily do it.
>>2903812I think the perceived danger is that the string is capable of 2500 amps in a dead short, so people say to limit it to four at most because the current is less.Meh a hydraulic or more likely a hammer punch crimp is designed for a proper connector and not a piece of water pipe, I don't think it will work.I could I guess put proper termination lugs on it and bolt it down to one of the batteries on top of the bus. Kinda starting to have concerns about distribution though, but I should be safe because the max amps is equal to the max control of any one battery so safety wise it's ok
>>2903711>Reflected light from the snow makes them better than ones that are angled 'right'sounds like a use case for bifacial panels
>>2903873A 48V big guy battery can do 20kA+ in a dead short so 2.5kA isn't so bad. The hydraulic crimper could cold weld the pipe just fine, provided you choose the right size terminal for the cross section. You should have a high breaking current fuse on the battery side of the wiring, at least on positive, and then have the thing enclosed. Each battery can give out 100A, totaling at 1000A, while your wiring is sized to 100A. The copper pipe and everything leading to the fuse should ideally be sized to handle 1000A peaks for a few seconds, until the 100A fuse gives. Either way the worst part by far is that the bars are in open air with nothing covering them.
>>2903881It really is, if i put any on that metal roof i'm absolutely using them.
>>2903890Ehh I bought all of the batteries because I was going to put them in series and make 120v dc.I bought a special charge controller and everything for it. But then I realized that if one of the bms ever opens up from temperature, low voltage, high voltage, ect, it would instantly kill itself big time and maybe go on fire.I tried ordering a 40s bms and the transaction went pretty bad and I refunded it. Now I'm stuck not sure what to do at this point so I just made it 12v for now.The 120v battery voltage is cool because I found a lot of my electronics just plug in and work fine on DC. I even modified my oven to work on either. But no proper bms is super sketch
>>2904038i think some bms could be put in series, but dont take my word on itdesu i dont know why systems that can be directly inverted to mains are not more common, it lowers the complexity a ton, needs way less copper.it is not that unsafe
>>2904064400-600V batteries exist, which are more closely aligned to solar string voltage. Only that they cost a fuckton. But "it's not that unsafe" doesn't cut it with electrical code.
>>2904067its more you need an actual electrician to sign for it, not that it cannot be used by codewhich i get, but its bullshit that only because of that companies barely do equipment for itevery fucking mains installation need the electricians signature already, why industry act like this is a big deal
>>2904064>>2904038>>2904069Any reason you can't wire two BMS next to each other? If the parameters are the same they should just ignore each other unless one fails.
>>2904112that is what i said, and there is bms for huge series batteries, seems like regular bms acting as slaves of a master controller, but they are kinda expensive
>>2904112>Any reason you can't wire two BMS next to each otherYes, there is a reason.Bms use a mosfet or multiple mosfets to disconnect the cells from the terminals in order to protect the battery.The mosfet is a piece of silicon, it has a maximum voltage limit of 60v or something.If you have a 128v nominal string of batteries, and any load at all, if any bms opens, there will be 128v between the mosfet now and it will rapidly start emitting fire and burn down your fucking house is what I was told.I was going to get around this by bypassing the mosfet and instead using the mosfet output to keep a giant contacter closed but meh I want something not quite so jank and I'd still need to balance everything
>>2904136you are getting it wrong, you need to split the bankexample you put a 60v bms in a 60v section of the bank, which is in series with another section like that to get the 120v
>>2904138Read what I posted
>>2904160you need to check how bms work dude
>>2904136>>2904138>>2904127Use a controller and a really big active pizeo switch as the BMS. If something fails it will automatically disconnect.
>>2904178Oh you're right, that's so cool, I hope one day you give it a try
