AC500 Not Charging from Grid

I have one AC500 with two B300s batteries. I ran the batteries down to about 10%. I plugged the AC500 into an AC outlet and left for work. When I got back this afternoon there it had only charged to 30% and no AC Input Power (0 watts), but still 120V at 60Hz. I unplugged the AC500 from the wall socket, turned it off, and then plugged it back in again. After about 30 seconds the AC input Power was around 1700W, but in a few minutes the wattage went back to 0. AC Input Voltage stays at 120V at 60Hz. What do I need to do to fix this problem? Thanks.

When I turn the AC out put on and the power is being drained from the batteries, the AC Power Input shows about 10W above what is being drained from the batteries (when there is 53W output the power input is 63W).

Unplugged and restarted a second time and the input went up to 1700W, increased the batteries to 31% and then there was a click sound and the wattage dropped to 0W.

Hi @SureHope
Thats strange, lets see if we can troubleshoot the problem first

You mentioned that you connect two B300S Batteries. Did you try to disconnect one of them and then try charging via AC500? When both work as a single unit, we can say that both batteries seems to be fine when run independent from each other. If you have a fitting plug, you can also try to charge the B300S without the AC500. With T500 for example.

Did you do any recent changes? Other Setup, Firmware updates etc.? Do you know for how long you have this Problem?

The AC500 have a log with error information. Did you have a look at it? Any Error Codes?

greetings
Erik

PS: Please @Selfmadestrom when you answer. Thanks!

Selfmadestrom, thanks for your response. I disconnected B3 and attempted to charge B2 without success. I then disconnected B2 and connected B3 and it charged to 31% and stopped charging. I connected both B2 & B3 and attempted to charge with no success (0W from Grid).

I have had no recent changes of any kind. The problem first appeared yesterday when I posted the problem. There are no Error Codes.

Thanks for your help. Not sure what to do next. When I was charging from the grid yesterday it charged to a total of 34% (B2 39% & B3 28%).

It appears to me now that the AC500 thinks the batteries are fully charged 39% and 30%. What’s up with that?

Maybe they are fully charged. Have you done a full discharge to 0% followed by a full charge to 100% to recalibrate them lately? That’s recommended every now and then to keep the % guess o meter somewhat in sync.

Thanks for your recommendation, eric102. I will try that this weekend.

I discharged the batteries to 0%, and then began recharging from the grid. The batteries got to 31% (B2 32% & B3 31%) and the input wattage went to 0W (stopped charging). It only took a couple hours to get to 31%, so I don’t think it is fully charged. Bluetti, what should I do?

I purchased an AC500 about a month ago and realized a few things.

  1. It produces random fan noise at full blast even though there is little to no load on it which makes absolutely no sense. (charging only from the grid at 5A) especially in average cold weather.
  2. It intermittently hangs every few days (latest firmware, Australia)…in which the charge amount gets stuck at whatever arbitrary low value such as 18% and the display seems to get stuck on that percentage whilst it still sucks power from the grid whether or not the UPS time is set to charge. In order to get it reset I have to disconnect and power cycle both the unit and the battery.

After which it goes from 18 to 100% after a minute or two. It’s as if the unit has charged the battery in the background but the head unit is busy daydreaming until it gets reset.

The AC500 seems to be a buggy hunk of junk. What is even more annoying is that there is no transparency over firmware releases or change logs …so everything is shrouded in mystery,

I only charge from the grid and the AC500is just horribly unstable,

Update on my AC500 and 2 B300S. only charging to 30%. I drained the batteries individually to 0% and let sit for about an hour. I then charged each one seperately with AC power. I did this three times with the same result each time. Each one would only charge to 30%. I was told to return the batteries to have them checked out. Bluetti said one of the batteries had damaged cells which would be replaced and the other was working fine. I told them how each one would only charge to 30%, so I could not believe one was working. I also told them that I would accept used batteries only if they can be charged to 100%, for that was the condition of my original batteries before the problem started. They replaced both batteries with used ones.

I received the batteries yesterday and connected them to my AC500. When first tested, one battery was charged to 71% and the other to 80%. I attempted to charge them with AC power and the AC500 screen showed 123 Volts at 60Hz but no Watts. The batteries did not increase in charge. I had asked initially if the problem might be the AC500 (because both my original batteries individually could not be charged beyond 30%), but was told it could not be the AC500. So now I have 2 used replacement batteries that will not charge beyond 71% and 80%. I am now waiting a repsonse from Bluetti to correct this frustrating problem.

Have you contacted Bluetti about this problem? Have the resoled it?

I suspect my situation might be different than yours as my battery does reach 100% and for the most part seems ok except from the occasional glitch about once or twice a week.

I suspect you might need to let your replacement batteries go through the drain and charge cycle a couple of times.

You are probably right about the drain and charge cycle. Hopefully Bluetti will get with me and give directions. Thanks for the reply.