diy solar

diy solar

New to Solar - Diving in head first

CavemanDS

New Member
Joined
Nov 30, 2021
Messages
16
Hey all - been reading the forums for quite a while trying to decide whether or not to pull the trigger on a solar project. My wife and I drank just enough the other night to convince ourselves that we should go all-in.

I spoke with @Amy Wan (Luyuan) - got a quote and made the decision to buy 48 of these puppies from her: 280Ah - 6000 cycle LiFePo4 LF280K

Cost Breakdown:
- $124.50 per cell
- $925 Shipping (To Oklahoma, USA)
- approximately $200 Transaction Fee (Credit Card Payment)

They are currently awaiting a delivery from EVE for these cells and informed me of this during our conversation. I am in no "real" rush for these as I still need to design and set up the charge controller, PV panel layout etc etc etc. She said the expected delivery time would be approximately 50 days. I'll update on this as I get info.

I already have 10 355w solar panels sitting in my shop doing nothing. Purchased them on a whim after I sat for 2 weeks with no power. I want to get those hooked up to an all-in-one inverter in the meantime. Haven't fully fletched it all out at this point but with (2) 200w panels in my house, I plan to move as much of my lighting/plugs as I can into a sub-panel to run off of solar while still having my heavy-load items such as the oven/stove/washer/drier/AC fed from the grid until I can scale the PV system up.

I have 2 months to get it all sorted/planned so wish me luck. After looking around a bit for an all-in-one, the Growatt 5k all-in-one inverter looks like a decent system so would love some opinions on them vs other inverters.

Thanks all!
David
 
Only thing that worries me is that you bought exactly the amount of batteries for 4x S16. You should have probably bought two spares in case some of them are bad. Growatts are not UL certified so be aware that if you require a utiliy inspection it will not pass and it may leave you vulnerable with home owners insurance coverage. If none of that is an issue for you then it will be fine.
 
Last edited:
Only thing that worries me is that you bought exactly the amount of batteries for 4x S16. You should have probably bought two spares in case some of them are bad. Growatts are not UL certifies so be aware that if you require a utiliy inspection it will not pass and it may leave you vulnerable with home owners insurance coverage. If none of that is an issue for you then it will be fine.
That's a good point - I live in an unincorporated zone within city limits but I plan on having an electrician come out and tell me what I can/can't do before I start pulling wires. I don't want to paint myself into a corner where I CAN'T sell back my overproduction so I need to plan for that. Good call.
 
If you want to do grid tie, everything in the install must be UL listed AFAIK, panels, electronics, everything. Make sure your panels still have all the needed labels, if you bought used panels lots of them have that removed.
 
Update: 25 days have passed. I reached out to @Amy Wan (Luyuan) on Dec 16th and she said they are supposed to receive stock by the end of Dec. I still haven't pulled the trigger on a charge controller/inverter yet. For some reason my mind won't let me click the button on those I think I'm experiencing analysis paralysis.
 
That's a good point - I live in an unincorporated zone within city limits but I plan on having an electrician come out and tell me what I can/can't do before I start pulling wires. I don't want to paint myself into a corner where I CAN'T sell back my overproduction so I need to plan for that. Good call.

Just my $.02 but personally I would focus on the PV and grid tied inverter and then come back and look at the expensive stuff like battery building. Let the grid be your battery. Yes if you lose power you'll be SOL, but a Honda EU 2000/2200 would be a good thing to have anyhow.
 
I have an 8500w gas generator, was the first thing I bought. Great advice and much appreciated! The generator was the only thing that saved us during the 2 week power outage we had last year. Trying to avoid the issues we had last year which is why we started this journey.
 
Update: 47 days have passed. Amy sent me a tracking number yesterday and received confirmation from alibaba that the cells are on their way. I'm still no closer to making a decision on the inverter. After taking a look at the MPP LVX6048 it looks promising. I've seen some reports of the all-in-one inverters becoming UL certified so I don't really know if it's worth waiting for that before pulling the trigger or getting some off-grid inverters to handle some of the work until I build up the system.

I have an electrician coming over this week to give me some ideas on how to configure everything to be expandable/upgradable so I'm looking forward to that.
 
If you want to do net-metering exporting power to the grid, in the U.S. you will need it permitted and inspected. Equipment has to be UL listed, at least to UL-1741 likely UL-1741-SA.
DIY batteries could be a problem for permitting. If you select an inverter which is batteries-optional, could start without. Could have a small UL Recognized AGM battery.

Solar and Battery are two different things.
PV costs $0.025/kWh (amortized over its first 10 years)
commercial batteries cost $0.50/kWh (by end of cycle life)
DIY LiFePO4 costs $0.05/kWh so they do have the potential to give you a payback.

Are batteries for peak shaving, and storing power produced by PV during low rate times for export at other times?
Or, do you want to operate while grid is down?

If off-grid, you need to determine maximum load and maximum starting surge requirements. Things like well pump or other induction motors have highest starting surge. These will determine what inverter capabilities are needed.

Prices are all over the map. Maybe $1500 for 48V GroWatt, $7000 for SolArk, $7000 to $15,000 for SMA, several other brands and prices in between.
You want something that works with 48V DIY battery. For some inverters, you can select a BMS it will talk to.

Some hybrids are the most economical package that uses a battery. Separate GT PV inverters AC coupled to battery inverter is another way to go. Separate also lets you get net-metering approval with simple GT PV system, add battery backed "UPS" later.

By the way if California, pending rule changes could eliminate all benefit of PV. You would want to get "permission to operate" before rules come into effect around May 2020, for 15 year grandfathering under old rules. Some other states attempting the same thing, maybe rules not quite so severe.

Since you bought a generator, look for an inverter which doesn't demand the generator be 1.5x larger. Some throw full load on generator, others ramp up load gently and regulate how much they draw from it.
 
Last edited:
Thanks Hedges - I primarily want to start off having some power when/if my power goes down that doesn't depend on gasoline. I would like to grow the system to eventually be 100% off grid.

I do have 10 panels @355w each at the moment and will eventually be connecting them to whatever inverter(s) I do decide to purchase.
 
Probably, you should keep grid as backup. And if net metering is available, storing power in it is more cost effective than wearing out batteries.
So consider grid-backup with just enough battery to get by. That might be accomplished by doing without some loads.

My battery has to run the house during the maybe 5 minutes PV inverters go off-line during a power failure (characteristic of AC coupled but not DC coupled systems.) And it provide starting surge for motors. Then while sun is shining, I can run A/C and anything else I want; PV is way oversize. At night, battery barely lasts until morning, and then only if I turn of certain unnecessary loads. It would last longer if not powering 4x old power-hog refrigerators. Having them switched off if (OffGrid && Nighttime) would be better.
 
Thanks Hedges - I primarily want to start off having some power when/if my power goes down that doesn't depend on gasoline. I would like to grow the system to eventually be 100% off grid.

I do have 10 panels @355w each at the moment and will eventually be connecting them to whatever inverter(s) I do decide to purchase.
No reason to go off grid unless at some future date they start charging huge fee's just for a connection.
You never know when two weeks of continual overcast days and bad weather will hit. A generator is great for short outages but you really want that Grid in place for those really bad weeks.
 
No reason to go off grid unless at some future date they start charging huge fee's just for a connection.
You never know when two weeks of continual overcast days and bad weather will hit. A generator is great for short outages but you really want that Grid in place for those really bad weeks.
That's a great point and I should clarify that. I don't really plan on cutting the electrical cord at all but would like to be at a point sometime in the future where I only need electric from the grid "some of the time". I think I used the wrong terminology which could be confusing.
 
UPDATE:

80 Total days
have passed since purchasing

32 days since I received shipping details - still no updates from Fedex.

These have gone up to $167.00 each. I paid $124.50 with the "Will Prowse Discount" but I think the list price was $128.00 each at the time. This price hike would have increased my total purchase price by $1870 or so. If that was the case 80 days ago I would have never pulled the trigger on batteries.

$7200 vs $9,000 - (I don't think so!!)

I don't even have the batteries yet but I think after considering comments both in this thread and throughout the forum I will be spending more on the PV Array in the future and let these battery prices settle out before considering any future investments. I think 43kWh will be sufficient as an emergency backup for now. Maybe Elon Musk will make his tab-less batteries available at some point.

Mr. Prowse did a video recently on rack mount batteries and the cost per kw is coming way down just in the past 3 months. I think that's going to be the way to go in the future.
 
Update:

After 128 days, the batteries have finally arrived. I'm still in the process of unboxing them. These things are quite a bit bigger than I had in my mind. I have tested 16 of them so far and every single one of them are precisely 3.296v. Now to get my BMS's and Inverter(s).
 
I've finally pulled the trigger on inverters. I saw Will's latest video on the EG4 6500-EX and decided to go with 2 of these. First time I tried to order, they said they were out and to call. I refreshed my screen about 5 mins later and there were some available so I went for it. I also ordered 3x 200a JBD 16s BMS so aside from some peripheral items I'm fairly close to being ready to set things up.

In the meantime I've been doing an energy audit to pinpoint what I want/can move to solar right away. Overall this has been a slow but fun project. I am a little over $11k deep so far. Here's the breakdown:

Cost per Cell (48 x 3.2v 280Ah):$124.50
Shipping/etc:$1,100.00
Cost per Battery Wh:$0.16
Battery Total$7,076.00
Cost per Panel (10 x 355w)$130.00
Shipping/etc$362.00
Panel Total$1,662.00
Inverter Cost (2 x 6500w)$1,300.00
Inverter Total$2,600.00
System Total:$11,338.00
System Cost per Wh:$3.79
 
Ordered 3 BMS from Amy on 5/22/2022. I was told from time of order to receipt at my door was 10 days.

I received shipping details on 6/10/2022 after asking where my order was. Amy said JBD was moving warehouses and apologized for the delay and provided me shipping details.

I asked a few times for confirmation - DHL was unable to locate the tracking number provided in the original communication.

I was unable to track those shipping details until today (6/25/2022). It looks like these didn't even ship until yesterday according to the waybill.
 
Update:

After 128 days, the batteries have finally arrived. I'm still in the process of unboxing them. These things are quite a bit bigger than I had in my mind. I have tested 16 of them so far and every single one of them are precisely 3.296v. Now to get my BMS's and Inverter(s).
Don't look at voltage that doesn't tell you anything for LFP batteries, you need to do a capacity test.

But if they are Luyuan cells then you should be good. AS LONG AS YOU BOUGHT THE GENUINE A grade cells and not the bulk cells.
 
Back
Top