I have an AC300 that I am using for home backup. I have AC Grid input connected that is limited to 6A (it is being powered from a no name 1000w inverter connected to a EV’s 12 V battery). The intent is that the EV would charge the AC300 through the AC grid input at 700W while the AC300 acts as a buffer to power the house. When the AC300 is not output anything significant, it works. The AC300 pulls 800W or so from the inverter and charges the battery while powering my networking equipment at 50W.
However, when I hooked up the AC300 to my house and it is outputting 1.5kW or so, it refuses to pull from my inverter. It would pull for maybe 30 secs and then complains that the voltage is high or low and then cuts off. Sometimes it would resume 15 minute or so later only to cut off again.
I then tried the same setup but I used the AC output of a Jackey 1500. This time the AC300 pulls it just fine when outputting 1.5kW to the house. I then used the AC output of the no-name inverter to charge the Jackery. And that works, but is very inefficient as there is another charge and conversion in the loop, loosing 20%.
AC300 low 50w AC output
EV 12V → no name inverter → AC300 (6A limit) = OK
AC300 high power 1500w AC output
EV 12V → no name inverter → AC300 (6A limit) = Bad no grid input
Jackery 1500 AC out → AC300 (6A limit) = OK
EV 12V → no name inverter → Jackery 1500 AC out ->AC300 (6A limit) = OK
Do we know why the Bluetti would refuse to pull from the grid if connected to certain inverters? How do I know what inverter it is compatible with?
Have you checked the output voltage of the inverter when under load? Some drop pretty low. Many appliances won’t care, but some might. I’m guessing the AC300 might.
Inverter output appears normal, but I only measured it when the AC300 is outputting 1500w AC but pulling 0 watts from the inverter. For some reason, when my AC300 is outputting 1500w, it refuses to pull power from my Amazon inverter. Though it would pull from Jackery 1500 AC output just fine.
In the situation when AC300 is outputting 50w AC, it pulls a normal 700w (limited to 6A) from the inverter and the inverter is providing about 118v
Ok, I got another inverter, this time a Ecoworthy 1100W pure sine wave off-grid unit. Same thing is happening.
Low loads 50-1000w AC output from AC300
EV 12V → Ecoworthy Inverter → AC300 = OK
EV 12V → Jackery Charger → Jackery 1500 AC output → AC300 = OK
High loads 1200-2000w AC output from AC300
EV 12V → Ecoworthy Inverter → AC300 = BAD
EV 12V → Jackery Charger → Jackery 1500 AC output → AC300 = OK
When it is bad, it makes a series of clicking noise and I get Grid Voltage Low and Grid Voltage High alarms. Sometimes it would make a few clicks, but it won’t pull any power. I’ve tried to set AC input Amp from 3-7A. The ecoworthy inverter is a 1100W unit, and the Jackery can supply 1800max.
This is the 2nd 1000-1100w pure sine inverter that the AC300 doesn’t want to draw input power from. Has anyone had success getting a heavily loaded AC300 to accept power from a 1000w AC inverter?
I don’t have the AC300, but doesn’t it have UPS mode? So when it’s connected to the inverter, it may be limiting what it pulls to charge the battery, but it also needs to provide power from that inverter to it’s loads/AC output.
Even without what’s needed to charger the battery, your high loads of 1200+ would exceed what the 1100w inverter can provide.
Maybe consider one of the other DC inputs using something to step up the 12v. Again, I don’t have the AC300, so I’m not sure what’s best to recommend.
I think the under sizing of the inverter might have something to do with it.
I used a microwave oven in isolation to pull about 1500w from the AC300
Turning on the microwave to pull about 1500w from from AC300, then plugging in the AC source limited to 6A input (660W at 110V, 720W at 120V) from the AC300 to see what would happen
- Real grid = OK
- Jackery 1500 (1800w inverter) = OK
- Bluetti EB70 (700w inverter) = BAD, exact same situation as the 1000w inverter before with grid voltage high and grid voltage low alarms, followed by AC300 not pulling any AC power.
The Bluetti EB70 is limited to 700w output, at 6A x 110V it should be 660w so it should be fine. However, it looks like that the AC300 grid input doesn’t strictly limit it at the set point, when it first switch over, it may exceed it for a small amount of time which causes a disruption in the inverter output that the AC300 interprets as an out of spec grid, causing the grid voltage high and grid voltage low alarm, with AC300 then refusing to pull power from the connected AC source. What’s strange is that the EB70 never shows an overload error and keeps going just fine.
My next experiment is to see if there is something special about the Microwave oven (non 1 power factor?) by trying a 1500w hair dryer, which as PF=1. If the same behavior persists, then I’ll try with a larger 1500w or 2000w inverter.
There might be a solution.
I emailed Bluetti support and they pushed to my machine DSP v4031.22 (I was running v4031.16). This turns on “grid enhancement mode”, which should really be called “dirty grid tolerant mode”. It seems to relax the limit that the incoming AC grid can fluctuate before falling back to inverter power. It allowed me to change using my 1100W inverter under low (100w), and high (2800w) load conditions, without the AC grid input cutting out. What did happen is that it did temporarily reduced the power it draw from AC grid, but then slowly ramped back up over the next 5 seconds or so without intervention from me. In the previous V4031.16 firmware, the AC300 would disconnect grid input when AC output spikes until I manually clear the alarms, making it impossible to use my inverter to feed AC into this thing.
There is a downside though. With DSP v4031.22, when the AC grid is disconnected, the switch over time from AC to inverter power doesn’t seem to occur as quickly. Before, it switches over without any hiccup what-so-ever. Now, out of the 20x I tried, once cut out for a few seconds causing my device to reboot, the other 19x, there seems to be a short reduction of AC output power, my lights dimmer a bit but nothing rebooted (router, switch and stuff).
I wish this firmware would make it a configuration option, but it is still a welcomed change for me in my specific situation. This is not good if you want to use the AC300 as an always on standby UPS, but is good if you want to plug it in to backup a load and want to partially charge it using AC.
This sounds like what I might need to make my bluetti run optimally with my generator.
I want to run my inverter gen on “eco” mode. The generator needs a moment to ramp up. When this happens it trips the AC300 to a low voltage fault. I can limit current input to 6A but that’s not always ideal.
My AC300 gets used 100 percent of the time in my camper. It’s wired in line between the power cord and distribution box.
I see you wrote that this is not an ideal solution when used as a standby UPS. What disadvantages would one have with the tolerant input programming combined with constant use?
From what I was told and in my experiment, the stock AC300 firmware is prioritize a short GIRD to BATTERY switch over time but is very intolerant on grid input fluctuations. When someone is slightly out of spec, it would think the grid is bad and refuses to use it. With the updated firmware (you’ll have to msg Bluetti to push it to your device’s serial number), AC300 becomes more tolerant of grid input fluctuation and will keep trying to use the grid for longer before cutting over to internal battery power. This means it may be more tolerant of your generator’s slow ramp up, but if your generate turns off (or you pull the AC input from the AC300), the AC output of the AC300 may drop off for a moment causing connected device to loose power and reboot. In practice, I’ve only observe this happen 1 in 20 times when I tried a disconnection test with the new firmware.