I’ve been considering the exact same used panels for my setup. Thanks for sharing how well it works for you! Now if I only had a welder in my family…
1 Like
This looks so good. If the interface of Bluetti app have the solar angle tips for everyone that would be great. Wonder the company try to add some function that come with weather forecast to inform the user to adjust the solar panel.
Very impressive set up. Thank-You for sharing esp with the pictures!
1 Like
Very impressive setup. This is exactly what my next phase of home power capability that I’m looking to achieve and your setup is inspiring to say the least. Are you within city limits? Did you have to deal with an HOA? I know both of those issues might keep me from pursuing your solution, but maybe not. Well done!
1 Like
Fortunately for me it’s a “no” to both situations. I live in a rural area so it was no problem for me. I hope you don’t run into any insurmountable issues with installing solar panels at your home.
Thanks for your feedback. Yes, I really hope I don’t have issues with the city or HOA.
Great job. Thanks for sharing your work.
1 Like
Just wanted to do a quick update. Today is a decent clear day, so it represents a good winter solar charging day. The system got down to 55% before charging really kicked in. This picture shows solar charging just a little while before getting to 100% full. It is still too early in the morning to get full charging from the solar panels as peak solar would be around 1:00 PM locally.
2 Likes
Nice job indeed, thanks for sharing!
1 Like
Wow! Great setup and documentation! Thanks for sharing this. I am working on doing nearly the same with the ground, 3 panels for 2 arrays on pole mounts…each panel is 75.1"x44.65". I don’t really have access to a welder, so I am trying to configure a suitable setup, but where is material like what you welded purchased?
Can you help me understand the SERIES vs. PARALLEL decision for the AC300?
I have 6*460w panels…VOC 41.52 (3 panels = 124.56v), 13.34a, 460w x 3 = 1380.
(BTW, I do have a 7th panel, but it is for direct connect to the B300…and to have on hand as a spare…but it could be used.)
The AC300 is of course 1200w, 12A, 150V per input.
Over on DIYSF, a member is recommending getting to 8 panels to do 3s2p, but A) I don’t understand it and B) think it exceeds the specs of the AC300. Not to mention, I would have to a day trip to get to Houston to get two more panels, the extra cost, and a more complicated ground array that I haven’t even figure out yet.
So, what would, if any advantage, would I get with 3s2p with an AC300, if even possible? I am not sure the member on DIYSF understands the AC300. Or, should I consider 2s2p?
One other question. I want to get a 2nd battery also. I am tempted to get the B300s. If you were to get another battery for your system, would you spend the extra money to get the B300s? Amazon has the B300 for $1800 vs $2300 (+$108 for the cable) for the B300s, and the official word from Bluetti is they don’t recommend the B300s on the AC300).
Thanks for your time!
Glad to share! Regarding the metal used for the stands, it was my son who got that. Some of it was unused/scrap material from where he works that he was allowed to make use of, but things like the 2x2 metal tubing he had to order new from a local supplier. I’m not sure what sort of supplier to look for, myself.
.
So, for the panels, when putting them in series you add the voltage, so 3 of your panels in series would output 124.56 volts, as you noted. Nicely within the AC300 limits. Your This set up is already over paneled since the power out is 1380, which is above the 1200 watts per MPPT controller. The factor that will be limited by the MPPT is the current, which will be limited to the 12 amps max. However, you can still over panel even further if you really wanted to. To do that you would get another 3 panels and put them also in series. Then you would put those two strings of 3 in parallel together. When panels are paralleled then the output voltage remains the same, but the output current is added. So you could use 6 panels in a 3S2P configuration, and the output would have a Voc of 124.56 volts still, but an Isc of 26.68 amps. The MPPT controllers limit the incoming current for charging, so this is not a problem. On a sunny day that would be a “waste” of the extra 3 panels, but on a cloudy day, or even rainy, you could still get close to, or up to, the maximum power input to the MPPT. Then do the same for the other MPPT (12 panels altogether), and you would almost always get excellent solar charging, and this would not harm the solar generator. Quite expensive, but if you live in an area that gets a lot of rainy and cloudy weather it could be the only option. To a lesser extent than this example this is what I have done with my setup. I have six 250 watt panels on each MPPT, so 1,500 watts on each, and 3,000 watts total for the AC300. As for going 2S2P, you certainly could, and would have 1,840 watts per MPPT. Whether that makes sense for the cost depends on your sun availability, and how much of a constant load you will have on your AC300. The higher the load the longer the time to recharge to 100%.
.
I have purchased an extra battery for my system, so I have the three. From my reading it seems that Bluetti doesn’t recommend using the B300s on the AC300, as you noted, and it seems to be related to the extra features on the new battery that aren’t usable on the AC300, like the built-in heaters. In my case the unit is in the basement, so freezing is not a worry. The only other difference is the higher current capacity since you can put 3 batteries in series. None of that helps with the AC300.
Have you considered adding electric heating? You could use it to supplement what ever system you have in place, assuming you need to heat your home. Looks like you are leaving a lot of potential power unused. Perhaps you have already found ways to use it more since last posted about it? Btw I think you have a very nice system.
My home has an electric furnace for heating; however, that would take far too much power to run off an AC300 (or even the new whole-home systems for that matter), I have a completely separate 100 amp service just for that furnace. However, I do have a backup forced-air wood furnace, and that is connected to my AC300. So if we have a power outage in the winter then we will use the wood furnace to heat our home. 
.
Regarding the potential unused power, that will always be the case. If one is going to size a solar-battery system to run a home or part of the home’s systems then you will always need to make the system have larger capacity than the daily use needs in case of bad weather, cloudy days, etc. So the batteries should be able to store close to 2 days of electric power (you will get some solar even on cloudy/rainy days), and the solar needs to be likewise able to charge well even on cloudy days. So, everything it going to be too large on a nice sunny day.
.
Having said that, I do have plans for making changes in my electrical panel and transfer switch to handle more of my critical loads.
Thanks for taking the time to answer all of the questions so thoroughly. I have plenty of sunny days in SETexas, and limited shade concerns. So, I think I will stick to the current plan of just 3s on each input…thanks to your input. I really don’t see over panning is going to be a big concern at this point.
.
As for the battery, I am only thinking about if I want to take a battery on the road, leaving the AC300 and B300 behind. But I don’t think the $600 extra would be worth it. Although, BE Admin has responded on another thread, and a directly connected PV would heat that B300s. 5 years ago, I would have said we never go below freezing for more than 10 hours. Then, back to back winters, we have had a blast that killed all of my citrus with sub freezing temps exceeding 24 hrs. So, I dunno. I think I am goi g to wait to see what Prime Day does for the price. Right now…$1800 vs $2400 (including the cord) is a big difference. I can alway get a B300s later down the road when they have dropped more in price.
.
Thanks for your time!
1 Like
Very nice and professional looking solar farm.
.
I set mine up just before Summer and am already having to move one of them around (it’s on lockable wheels) as the sun’s path gets lower and lower each day. It is starting to cast a shadow on my main array late in the day, which is when I need the batteries fully topped off before the sun goes down.
.
I bought an electric heater to prepare for winter to see if I can do without the home’s central heat. All the portable heaters are power hungry, as bad as the window A/Cs I used this Summer. When you read the reviews a lot of people can’t use the highest setting without tripping a 15 amp circuit breaker. At least Vegas rarely gets below freezing, but I have had to break up the ice in my pool a few times.
1 Like
When you have enough panels to max out everyday, you’ll find you’ll have a lot of leeway with the monthly angles. The biggest difference is from aiming them east-west, unless you can still get to 100% just leaving them aimed generally southward, like they count on with rigid rooftop panels.
1 Like
Can you share any settings you use in the ac300 that differ from factory in order to get the most out of your setup? I have the exact same setup, 12x250watt used panels grouped the same way series-parallel. I was only getting 600 watt input in pretty full sun. If I change the “enable parallel” setting to “on” I jumped up to 1700 watt pv input, but then everytime the sun went to shade I’d get a “parallel error” alarm sounding and input would drop to 0.
I also noticed today that my battery was down to 66% and sun was out but my pv input was 0. But if I unplugged one of the dc pv lines and plugged it back in all the sudden it started charging. I’m wondering if I have something wrong in the setup/settings or if for some reason my ac300 is malfunctioning. Any help or input would be appreciated I don’t really know the ins and outs of this system yet
I don’t believe I have changed any setting related to solar charging on my AC300. I do not use the parallel option with my solar panels, rather I ran a separate pair of wires to each of my two solar arrays, so they are individually connected. Each array is a set of 6 panels, connected as 3S2P.
.
Now, perhaps it could be related to the settings in the “working mode”. I have set mine up as “customized UPS”. From there I selected the “grid charge status” as enabled (I use that with my generator in case I would need that. I’ve tested to make sure it works, but otherwise have never used it), and set the “time control status” to disabled. Also, the SoC setting is 5% to 90%. Maybe try that and see what you get?
Since I originally made this post I have added two refurbished B300 batteries to my AC300 system, so it’s time to update the picture of my AC300 system.
And I didn’t include the DC breakers to disconnect the solar arrays, and that’s important enough that it should be included too.
2 Likes
Looks awesome.
Quick question; Even though my AC500 and AC300 wake up with the sun, some batteries randomly stay off. I can’t help but this the power on buttons are unreachable in your case now. Does that mean you never need to manually power on some of them in the morning? Maybe they stay on 24/7 and you don’t have this issue though 
1 Like