Bluetti AC500 w/B300K battery for our home backup/supplement system install and review

I did my homework and looked at several solar power stations to give us some backup power and to help supplement our over 1000KW electric bill. We aimed at reducing it by a third to start due to cash availability. Put a $2000.00 limit on the power.

The main thing is I wanted a simple system that did all the thinking for us similar to the Hybrid inverters which has what "they" call an "SBU" setting in the UPS mode. Solar first, Battery second and lastly Utility(grid power). But still allows some battery for the backup needs(this setting is adjustable). AFAIK Bluetti is the only power station that has what they call PV priority UPS feature. Very similar to the Hybrid inverters. I honestly was hoping that either Ecoflow or Anker in my price range that had something similar in their firmware or mobile app. But I could not get straight answers to that feature!

More to be posted on the AC500 once I get this setup and working. Edit: The main unit arrived, But the cable that connects the main to the battery is MIA. So I'm on hold waiting for support to contact me on what gives!

Preping for the power station I added a sub panel with an interlock that I can switch from the main panel(grid) or the power station. It has a generator plug that the power station can connect too. Also has the ability to expand to 240V if we need to down the road. The sub panel is rated for up to 100 amps. I have a 30 amp main breaker and a 30 amp breaker for the interlock. I used a NEMA L14-30 generator plug made by Reliance with a 30 amp rating.



I currently have the small Pecron E1500LFP connected so I could test out the circuits and check how much load I was putting on this. But the Pecron is limited when it came to PV priority. It would switch to grid power and did not leave any room for the battery's to except solar. I was manually switching and it was too easy to forget. Let the battery run down to far left no room for backup and it never really would except full solar when plugged into the grid.

 

Got a hold of Bluetti support. Seems they forgot to ship the cable. A bit unhappy about it, But I should see it 2-25-25. WTH, Grrr and

Edit: Cable is out for delivery!

 

While waiting for the cable, I ran over to Harbor freight and bought a cart to put the power station on. About ready to start my installation and setup. Cable is overdue. Putting the cart together while I was waiting.

Cable is here and I have it all connected. Set the unit to PV priority UPS. Plugged in the AC out cord and AC in cord. Simulating the PV(solar in with a 48V battery to test. But it all seems like its working. Pic's

 

After running this for a bit and testing the PV in. It switched to the battery power. I just need to wait to see if it switches to the grid power once the battery gets below 50%.

So far pretty darn happy and its much quieter the the small Pecron E1500LFP I have. But I'm also barely using the inverter with less than 500 watts. Max draw I saw with the furnace kick on was 1600 watts. Here's a pic of the app

 

Thank you! Actually seems to work as described.

Only thing I see so far that I didn't think of is when it switched to grid power it was drawing approximately 35 watts more than the actual usage(example 335 watts from grid- 300 watts out to the sub panel). So I switched it off for now until I can gather more free energy from solar to override that loss. But overall very pleased.

Today I'll switch that back to how I want it once the battery is built up.

Next up(never seems to be over) is getting the 2 panels I have in series instead of parallel. Now that this unit allows higher voltage compared to the Pecron I can do so and hopefully utilize more solar in. Pecron was limited to 700 watts. This will allow 2 feeds of 1500 watts(3000 watts total). So I'd like to get as close as possible to the 1080 watts the 2 panels will make.

Then its add 2 more panels sometime this spring/summer when its a bit warmer out for 2 strings(2160 watts). Eventually when $$ allows, I want 3 strings of 2 panels to the combiner box. 6 panels total for 3240 watts and then split it once it comes into the AC500.

Pic of the combiner box I previously installed! It has circuit breakers for the each string(16 amps) and a main disconnect to isolate the PV power if I need to work on it. Also has a surge protector for extra safety.

 

Well I do stink at neatness!

I'll work on that once I figure out where its going to live. I got some junk to move around.

 

Panels are parallel currently(50V). Under the voltage the Pecron can handle. I have a 400W mobile panel for the garage once I switch the roof panels to series to boost the voltage for the AC500(100V).

I'll be sure to keep them seperate.

That shocked me as well. I expected it to do as your EF's are as its only pass through.

Email to Bluetti support said its to power the inverter. Same will apply to the DC from the batteries but its not shown. He claimed the AC inverter loss is approx 1% and the DC inverter loss will be approx 15%.

One other odd thing is doesn't have a time of charge remaining like you EF's or my Pecron. Just battery percentage. They don't even display battery voltage. I also complained about the battery voltage to Bluetti support. Its something I got used to monitoring with the Pecron and the Victron out in the garage. I got crickets on that one!

 

Not much sun today only pulling around 100 watts. Shut off the interlok and will just let the little bit of solar we get charge the battery. But took a pic of what we saved on the e-bill yesterday. Not much($0.49 approx 1.6KW's) but it's something. 50 cents a day is still roughly $15 bucks a month give or take.

Need a warm day to go up and work on the panels!! I hope once I put the panels in serial it will capture closer to the 1080 watts per hour it should be, Also going to adjust the angle of the panels too. Bought an inclinometer to get the recommended angle of 34º.

 

High wind warnings for tonight. So I let the little bit of solar we were getting(350 watts or so) charge up the battery to 85%. Changed the SOC setting to 85% and the unit is acting like a UPS for the critical stuff(Furnace-fridge-freezer). Using about 31 watts an hour as a UPS, But worth not having to get out of bed at mid-nite if power goes out. 85% should last about 8+ hours. Priceless!!



This is the SOC screen, I changed the setting to 85% for backup, 50% when gathering solar. If I caught a bit more solar today, I would have set it as high as possible. With not much bright sun I was surprised it got up to 85% to be honest. If I moved it up higher, It will pull power from the grid to charge the battery, But at 1800 watts its a bit expensive IMHO.

 

Once I get the next expansion battery, I should be able to keep it at 80% and still have room to capture the solar.

It was nice sleeping without worry of an outage. Between the furnace and the sump pump(which is getting a workout with the rain and sn*w melt) are the 2 main worries!! Don't think we had an outage, But since I've been up, we've had 2 blips. One of my UPS has the annoying beeper that lets us know. Not even a flicker on the kitchen light. Microwave and stove flashing the time as well!!

 

I saw this video about the Pecron power station.



I had a spare cable for the Pecron and fabbed up my own to try and it works! Its bidirectional on the Pecron, So it will charge batteries and once topped off, The batteries will add additional storage to the power station. I took the 4 spare 12V 20ah batteries I had been using on the pellets stoves UPS as the stove is down while we run the furnace. Connected them to make a 48V battery pack. Connected the Pecron back up too the sub panel and solar for a test. Its was ugly, But temporary as a test only! Well golly it work's! This pick is when I had the battery connected to the solar in on the Pecron. 2nd pic is the cable I made up with the anderson connector.





So I grabbed the extra cable(P090A) that came with the Bluetti B300K battery. Fabbed up a cable with an Anderson connector. Added the 48V pack and it also works on the Bluetti. Only draw back is it needs to be disconnected to shut the Bluetti unit down as it keeps the Bluetti BMS active and won't let it shutdown. The pecron did NOT do that!

I then picked up 4 12V 100AH batteries and made a large 48V battery pack. Its now on the cart under the Bluetti and has added 5120 wh's of additional storage.

 

How I tested to see if it worked. I charged the solar station to 100%. Disconnected the external 48V battery pack. Ran the power station down to 50% and then connected the external battery. I watched the display on the power station gradually increase its state of charge without having any other charging source connected. The solar station balanced out at about 80%.

My plan is to eventually grab a server rack battery that has circuit protection and an off switch. I may also open up the Bluetti B300K battery and make the connection at the battery instead of off their BMS. This will be work in progress as I am still just winging it! But this should cure the power station not shutting down when I want to. For some reason the battery connected to the external port keeps the BMS active, Connecting straight to the battery will allow shutdown. Hopefully this will allow a more affordable alternative than the overpriced proprietary Bluetti battery packs!!

Server rack 5120 wh pack = $800 Where the 3072 wh Bluetti B300S is $1400+

For now, I'm only connecting the external 48V pack when weather warrants the possibility of outages or solar is active. This 48V pack will reside on the cart, But once I get the server rack battery the 48V pack will only be used/connected when weather warrants.

I will also add a battery buss to the cart where the batteries will connect. But thats another day!