You are not going to find a battery system that is cost effective (i.e. saves you more than it costs) unless you live in Hawaii, or unless you are on a real time pricing program (unlikely.)
OK so some notes:jimmyhackers wrote: ↑May 04, 2018 11:56 amthanks for the info. looks like i need to provide a little more info
the sunny boy is not battery capable. its only version of off grid mode is to stop feeding power to the grid if the grid is shut off.
we are also not on a real time pricing program. however....as i said we get paid "reimbursed" per kw produced regardless of whether we use it or we dont and it just feeds the grid.
i pretty much use two computers to mine crypto currency 24/7 so the houses constant usage is around 700-900 watts of total power used constantly.
my panels can produce anywhere upto 2kw of power per hour. meaning at these times im getting power im not using. it also means if i could store that energy and use it when its dark or the panels arn't working id save some money.
i have a rather large amount of agm lead acids ive collected (over a kilowatthour of storage) so i was looking to try and use them.
also my current inverters working input voltage range is 211-480v meaning some times (every day) my panels are still at 200volts or less and are not being used.
as far as i can see...i kinda have two options. find a new more efficient better hybrid inverter that works with my batteries and panels with a wider input voltage range.
or i can get a box of tricks battery inverter to add to my current one that will work with my batteries.
i juts cant find the right box of tricks for the right price (under 500 quid)
That's true for solar - ROI is 10-20 years in most places.
Sure, you can do that. UPS batteries are good for about 100 cycles so you could get about three months out of a system like that. If you are really going to try that, I'd recommend:NEW IDEA: most of my houses load is focused on my two mining pcs. about 350watts a peice.
what if i heath robinson a computer UPS (i have one going spare) with my battery bank so it could feasibly run it for a lot longer than intended on battery power.
Can you be more specific than.... "running a LOT of stuff for a very long time"....??
this is just for testing and just messing around. it has been torn down already.
Tapping the wire coming out of the panel is no different than putting that entire system on a different breaker.jimmyhackers wrote: ↑May 08, 2018 10:36 amhttps://www.ebay.co.uk/itm/500-600-1000 ... qhYeSnuY4Q
i wish someone would of linked me to something like this earlier..
It was a 12V inverter (10-30V) running off a 14 volt system. (Very small battery but DC/DC kept it at 14V.)
That's the rub. "Meeting UL 1741" means it works and has been tested.it also says it has islanding protetction....not sure its up to UL 1741 spec though.
That's on the output. The input assumes a solar panel. Solar panels current-limit themselves so there's little risk when used with this inverter.the add says "Protection: Islanding; short-circuit; converse connection; low voltage; over voltage; over temperature protection"
but they could be lying.
I think you will see far less power than that.i was looking into the peukert effect again and running the numbers..... a 1000w inverter will draw 41-42amps from a 24v battery at full power. A 22ah battery will give 22ah at a rate of 1amp every hour for 22 hours.
you are reading it wrong i think.
Right, that's what I said.flippy wrote: ↑May 09, 2018 5:43 amyou are reading it wrong i think.
the problem with "island" capable inverters like this is that they will keep sending power on the main grid when the grid is off. so line workers will still get shocked when they work on lines because your inverter is still dumping power onto the grid.
Yes, that would be a more direct way to do it. However, most grid tie systems operate between 300 and 600 volts, and the MPPT you will need to work at those voltages will be very pricey indeed. (>$1000)what you can do is run a regular MPPT charger for 48V batteries and charge a lipo pack with it. lipo is bascially the same voltage if you use a normal 14S pack you a right on the voltage range of regular lithium.
OK so now you are looking at supplying all your loads from a lipo pack. That can work - but is going to be expensive and dangerous. (A 10kWhr pack going up will destroy your home in short order.)grab a 48V inverter from aliexpress: https://www.aliexpress.com/store/produc ... 20376vuLwu
only thing you need is a decent MPPT charger rated for 48V and your panel voltage.
If it's going to run your home I would avoid "cheap relays and stuff." If your house catches fire you could lose everything - and your insurance company will be sure to notice your "cheap relays and stuff" during the investigation.with this you can run a entire fuse in your fusebox at full current. when the battery drains you can switch on reguar mains if you add some cheap relays and stuff. but it needs to be built in such a mannter that inverter power cannot enter the main grid.
This is one of the many ways that several inverters can "island" and run a portion of the grid, putting utility workers at risk. Another risk is that largish motors are running somewhere on the grid nearby; these stabilize the grid and can fool an inverter into thinking that the grid is still there.jimmyhackers wrote: ↑May 09, 2018 7:33 amim pretty sure the inverter i posted although worded badly has islanding protection...
meaning it requires a mains input to work. meaning if the grid did go down....it should turn off.
although....im not sure how it would work in conjunction with my existing solar inverters islanding protection....
if both were on and producing power they could trick each other into thinking the grid is still live and keep producing.
technically this shouldn't happen for me as the battery inverter wont/shouldnt be on in daylight hours.
it does make me wonder though if two houses were next to each other with solar panels and grid tie inverters, couldn't a similar thing happen?
Yep. But it was being fed by a 70 amp DC/DC. The battery was only to provide a lower impedance to the inverter.it could be your inverter was running at its lowest power setting as it was close to its lowest dc input power, so it may of run better off of 24v. you also would/could of been losing efficiency and maxmum amps available with you dc-dc converter. 500w at 14v will need 35amps.
that's a lot to ask of a little battery. a 22Ah lead acid battery will give out about 5-10Ah at that kind of rate before its flat.