AC500 discharging 400 watts + 24/7

I recently changed out my AC300 for the AC500. With the AC300, loads would drop to 150watts and even read 0 for short periods, but since I switched to the AC500, discharge is never less than 400 watts continuously.
This uses all my batteries (4 B300s) every night forcing me to use grid power every night. While it is offsetting my usage, it is disappointing when my AC300 could power my loads for days.
Anyone else have this experience?

400 watts of constant use for 12 hours would use up 4,800 watt-hours of power. You have 4 B300 batteries, each with 3,072 watt-hours of capacity. You should be only using about 37% of your capacity. So, something else is going on with your system. Is it possible you have the UPS mode configured differently on the AC500 than you did on the AC300? Is it switching to utility power at a higher threshold than previously set up?


Hi @Birvin

Do you mean that your system with the AC500 now draws 400W instead of 150W with the AC300?

For sure the AC500 has a bit more selfconsumption because of the bigger inverter, but it shouldnt be that high. First thing you should do is to update your AC500 and you B300 Units to the latest firmware. Also what @hnymann mentioned regarding the UPS mode is a important thing. Some of the UPS Modes leave the inverter only in a standby instead of turning off. This cause also extra battery drain.



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Something is definitely wrong.

I have an AC500 and 6x B300S.

During nighttime it’s using an average of 275W/Hr.

Consumers are: router & boosters, security system with 5 cameras, fridge, freezer and some lights.

@hnymann i have other loads with a peak of 1.2 Kw at times. I’ve overpaneled and get 2.2 Kw solar for about 3 hours a day. I’m using PV priority mode drawing AC at 50%.
With the AC300 the batteries would easily reach 100% and have between 10 -30% by morning keeping me off grid for days (I had a lower SOC then). With the AC500 I rarely reach 100% because of the 450watt constant load and I’m only having to charge from 50% drain.

Load: refrigerator, window AC in storage shed, shallow well pump (currently off), crawlspace dehumidifier, sump pump, lights, TV.

Also, I need to recalibrate the batteries which have a 15-20% discrepancy.

Last year may not have been a good baseline since we had drought conditions and this year has had a lot of rain.

I’ve also realized the dehumidifier is running much more than it used to so I’m trying to troubleshoot if that is due to humidity conditions or a faulty hygrometer keeping the unit continuously on.

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@Selfmadestrom definitely want to check firmware updates when I’m back from vacation.

@Bikerwally this could be a load issue, but still seems odd I can’t reach 100% charge from 50%. Once I get back I’ll start eliminating load to see what the unit is doing on its own.

Hi Birvin,
It’s good to know how much power (Watt) your appliances are using. You can use a power plug or a watt meter to measure this.

The AC500 is using around 30 Watt/Hr without anything connected.

Converting DC from the batteries into AC also takes some energy, my guess this would be +10%.

This means if appliances are drawing 1000 W, the AC500 will use 1000+100+30= 1130 W.

@Bluetti, please correct me if I’m wrong.

@Bikerwally The reality is similar to what you estimated.
Because 90% efficiency needs to be taken into account when discharging the machine, the machine will also have a certain amount of self-consumption.