I finally found out why my AC500 would not turn on. Two of my four batteries discharged to zero volts and the AC500 power shut down and could not be powered on.
I was told by a consultant that to proceed, I had to charge up the two batteries that discharged to zero before I could proceed. I ordered a T500 500-watt charger to charge up those batteries but the T500 has not yet been delivered. I have another solar array of 8 panels that I built that makes it possible to charge each of my four batteries through the DC input directly to the batteries DC input. I did not want to wait for the T500 to see if could use just two batteries to do a test so I connected the two fully charged batteries to the AC500 and the AC500 powered on since I had taken out the two B300S batteries that discharged to zero until I could charge them to full power. When I did that, I could power up the AC500 with all four batteries which I could see on the AC500 display. I used my 8 solar panels which are independent of my normal solar power which is directly connected to the AC500. I connected those 8 solar panels wired so I combine two solar panels in parallel which gives me four independent DC lines. Each line produces a maximum of 10A at 31.7 volts at a max 317 watts about noon in full sun. I had some cloudy days, so it took me a couples of days before they were fully charged to 100% which was the SOC of 100% of my other two batteries. Once all batteries were charged to 100%, I connected them all to the AC500 and I was able to power on the AC500 and could see on the display of the AC500 all four batteries and the SOC which were all 100%. I then disconnected all DC inputs to all of the batteries and turned off my normal solar input to the AC500 to see what would happen with AC load turned on and connected to all of my refrigerators and freezers. I have two refrigerator/freezers and two freezers. Normally with full sunshine, I select working mode as only PV for UPS and solar arrays power all those devices on a continual basis. Any time I get a cloudy day, I change the PV priority for UPS to use the working mode standard UPS which uses both my PV from solar sources and the grid as needed.
However, the two batteries that discharged to zero before, are now again the only ones that are discharging as before. The other two batteries are at 100% in a standby state. After documenting the discharge and which batteries are contributing, it is apparent that the same thing will happen again where two of the batteries discharge to power the AC load (my appliances) and the other batteries stay in standby mode.
Without some intervention and change, my four batteries wired in parallel, is effectively only a two-battery system. In the past, all batteries were all contributing within reasonable discharge rates, though not identical, were close enough. I have updated the BMI firmware, but I can predict that some other change is necessary to get all four batteries to share in the discharge to power my AC load. I am aware that the Bluetti AC500 has to learn through charge and discharge cycles of at least two cycles to normalize but I do not think that is going to happen my system for some reason.
Anyone have any suggestions? gerald.w.bradshaw@gmail.com (could not change the type above for my email address)
So just so I am clear, when you have all 4 batteries connected to the ac500, they do ALL show up within the app as connected devices and you can see their status, which is 100% and labeled as in “Standby” state? But when you connect output loads to your AC500, the unit will only discharge from 2 of the batteries? Leaving 2 of the 4 batteries at 100% SOC while the other deplete to 0% and shut off your outputs??
Yes.[quote=“m.briney, post:2, topic:28159, full:true”] @bluetti_geraldwbradshawgmailcom Sorry to hear about your issues Gerald, but lets see if we can get this remedied for ya.
So just so I am clear, when you have all 4 batteries connected to the ac500, they do ALL show up within the app as connected devices and you can see their status, which is 100% and labeled as in “Standby” state? But when you connect output loads to your AC500, the unit will only discharge from 2 of the batteries? Leaving 2 of the 4 batteries at 100% SOC while the other deplete to 0% and shut off your outputs??
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I have had this problem happen twice. It is not clear how to fix the problem.
Have you tried to wire them differently?
I noticed some of our AC500 batteries not turning on in the morning.
Then I changed the way the batteries were wired (we have 3 of them) and our issue occurred much less often.
@bluetti_geraldwbradshawgmailcom yea as @amandine mentioned above… have you tried orienting the batteries differently? Maybe try swapping the 2 that are working, with the 2 that arent, as maybe it’s a faulty cable or something? This could help try and diagnose where the issues stemming from as what you’re explaining definitely doesn’t sound like everything is communicating the way it should.
Wasnt there a firmware update for AC500 to better balance the B300S?
@bluetti_geraldwbradshawgmailcom i would recommend do use the forum search. Im pretty sure, there was a similar topic already here that could be solved via firmware
My AC500 with four B300s system is now fully functional. I had a misunderstanding about the cable connections but as soon as I understood and implemented what I came to believe was correct, my AC500 power came on and all batteries reported as being on line.
I found that I had wired the last battery in the string on the wrong port. As soon as I changed to the top port, the AC500 turned on and all batteries went on line and are functioning properly. Such a simple error but so significant.