EP500 SOC Low parameter fails to operate as Bluetti designed

My EP500 fails to stop power the loads (AC and/or DC Out) after it reached the SOC Low preset setting. It continue to run until the batter capacity drop to 0% until it self shut off. SOC High works perfectly as described in the manual.

Have anyone has this issue?

My EP500 using SOC of 30% and it is working fine. This mode is a UPS feature so It must be plug into the wall. When my unit hit 30%, it draws power from the wall. Bluetti has a power that it will not tell you that the AC grid is powering your load. I have asked Bluetti to fix it, but been ignored.

Hi @randychan38,

Thank you for your question.
May I know what mode you have set? And was the EP500 charging all the time when this situation happened? In addition, when we set the SOC, it can only control charging, not control discharging.
Any further question, please let me know.

When it is in Standards UPS Offline mode. It draws power from the AC Grid bypassing the battery inverter powering the load. If it is in Standards UPS Online mode, the inverter will power the load with the kW needed to power the load. The AC Grid and PV Inputs supply to the battery at the same time. Anyway, I did find and update my EP500 Firmware to the latest version a couple of weeks ago. I also reloaded the battery to 0% then 100%. I am going to retest all UPS modes and parameters options to see if it makes any change to the symptom.

Bluetti Admin, Thank you for your response!

I was going by the description stated in the EP500 User Manual, on page 30, under section 10.2.3., Time Control UPS, Parameter Setting said;

"Parameter Setting: Battery SOC Low: When the remaining capacity of EP500 is under the preset Battery SOC Low state, EP500 will stop powering loads connected to AC output port of EP500 or Sub Panel.”

Nonetheless, I did find and updated the firmware to the current version. I am going to retest just this function through each and every working mode.

In the meantime, I have a question (I have sent this question to sale@bluettipower.com as well). When the display shows the battery capacity at 0% and even until it automatic self shutoff. How much battery capacity still remains?



Would you tell me what UPS mode you were running with SOC of 30%?

When your EP500 hits 30% and it switches to draw power from the wall. Does the battery capacity stay at 30%? So, the 30% capacity is to be reserved for emergency power outage use.

Hi @randychan38,

If the SOC shows 0%, it still has 20% power to protect your unit.

The mode is “PV priority UPS” This way I save 70% of battery charging for solar power. Yes it stay at 30% and the AC Grid power is WRONG! My Kill-a-Watt says wattage like 500 - 1468 watts from the wall.

Hi Harlan,

Thank you for answering your specific working mode operation. In your case, your (so as mine) EP500 work as per Bluetti’s User’s Manual described for PV Priority UPS mode. The EP500 is supposed to cut of input from the Grid when it charges reaching the preset PV Charging settings. So, when it reaches 30%, it stops the AC Grid Input power but continues the charge by the Solar PV Input port until the battery is full. This is for purpose of saving on utility bill. The problem with my EP500 is in Time Control UPS Mode which I see the operation is a little more involved.

Not quite understand your mention about “AC Grid power is WRONG!”. If you have your Kill-a-Watt plugged on the AC wall outlet, then your EP500 plugged in the Kill-a-Watt. The Kill-a-Watt meter should register the raw power from the wall outlet. Not sure what did you mean about the wattage like 500 - 1468 watts?

The AC Grid Power should be the same as the Kill-a-Watt meter. It is not in the PV Priority Ups Mode. It is off by hundreds of watts sometimes.

The AC Grid Power should be the same as the Kill-a-Watt meter. It is not in the PV Priority Ups Mode. It is off by hundreds of watts sometimes.

The specification in the User’s Manual says the AC Input is 600w. My EP500 display screen shows the Grid input is around 560w. And the monitor meter on my wall outlet registers slightly higher wattage. I think the small different is being using in the EP500 internally. The AC input power is in pass-through when in Standard UPS Offline mode to power the load. So, the wattage from the AC wall outlet do supply full wattage to power the load. In my case, my load takes up to 1400w. But the EP500 AC Output only supplies 1268w because wall outlet is limited to 12A which is around 1320w.

Good to know. Thank you! So, the 20% hidden buffer should prevent damaging the battery. Especially my EP500 have had dropped to 0% and forced automatic shut off a few times.

The 20% is included in the screen’s 100%. That will protect your unit to some extent.

First of all, what User’s Manual says 600w? My AC200max comes with a power brick that has a max of 600 watts. The EP500 is plug into the wall of a 20 amp circuit breaker so it can deliver over 2000 watts. Second, my EP500 AC output has a 2000 watt inverter, so I can run appliances up to 2000 watts, not 1260 watts.

The EP500 User’s Manual, page 34 Specification states AC Input. It is referring the max input 600W to charge the EP500 battery. The AC Output does say 2000W.

That 600 watt reference is the charging of the battery internally, the AC power input only come from the cable the plugs into the wall.

I apologize for misunderstanding. Thanks for clarification. I’ll leave Bluetti to answer your question. I am still doing my own testing through all possible operation options on the EP500.

I have two EP500s, two AC200s and AC200max with batteries, so I had to try many different configurations. My battery room has so many wires and plugs that it reminds me of “Green Acres” where he has a generator and can only plug in units that equal 7 (wattage). Do I plug in Refrigerator or space heater; or lights, appliances? I try to balance the two EP500s with the loads less the 2000 watts. Life is Good.