Battery Cell Voltage

Hello and happy holidays. I’m still having battery deviation with my BMS. I’m offgrid in my van and discharging it and fully charging it is pretty difficult as i have no access to shore power.

If i charge with AC while driving with my inverter sometimes it stops a 75% to 85%
Then when i stop and set up my panels it will jump to 100%

I’m wondering if people who have the AC200 and first versions of AC200P that allows you to see the battery cell voltage could let me know what the voltage is at 100% after recalibration.

It would help me guage how full the battery actually is because two things are possibly happening…

  1. It is at 100% even when only reading 75 to 85% (not a big deal in my eyes)
  2. It reads 100% but is actually at 75% to 85% (big deal because I don’t have access to a full battery capacity


So again if anyone could please give me a voltage read on the 16 battery cells preferably after calibration it would be really helpful!

The attached photo is at 71% charge but wanted to show what I’m referring to

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I will try to help but I’m not sure what you mean by after recalibration. I have the early AC200P genie so I can capture the pic for you (if I can recall how to post a pic) at 100% charge.

Just to verify…Is ours an AC200 or an AC200P?

It is an AC200P

thank you

Sorry I can’t help. I have an AC200 and the individual cell voltages are higher on that model due to battery chemistry differences


I have an AC200P. I discharged down to 0 in November and fully charged the unit. I plugged in the charger just moments ago to ensure the until is fully charged. Here are my readings.

Is this what you need?


Yes thank you and appreciated!

So my battery is at 76% right now and the average cell voltage is 3.38 which is higher voltage than yours is at 100% can someone explain that to me.

Is yours by chance an AC200 and not an AC200P? The AC200P utilizes a different battery chemistry with lower cell voltages vs the AC200 which has different batteries with higher individual cell voltages. If you do in fact have and AC200, that could explain the difference.

Apparently I do have the AC200 as it says in the settings menu. I was almost positive it was the AC200P… it does say 2000w and 2000wh on the front. Isnt the ac200 only 1800wh?

Looking at my invoice I was sold the ac200p

The AC200 will show 2000 W (inverter capacity and 1700 WH (Battery Capacity) on the outside of the case as pictured below. The AC200 was offered during the kickstarter offering only. The AC200 has 1700 watt hour Lithium Ion batteries. The AC200P has LifePO4 batteries with a 2000 watt hour capacity and will show 2000 and 2000 on the case I think the product information screen only shows AC200 on both the AC200 and the AC200. The 200P became available if memory serves correctly in December of 2020. When did you purchase and receive your AC200P?

The individual cell voltages were a display feature only in the AC200 and the very early AC200Ps. The cell voltage display was eliminated after a few AC200Ps came out and no displayed cell voltages are the norm now. If you indeed have an AC200P that shows the cell voltages then yours would have been the early production AC200P.

I have an AC200P and just checked the cell voltage on the display. They are all at 4.08 and 4.09 volts with a 100% state of charge after sitting fully charged for 90 days.

Here is what my AC200 Product Identification on the case looks like.

Here is my product info screen which shows the model number

Here is my cell voltage screen (100% after 90 days storage)

Here is my main AC200 screen showing 100% state of charge.

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This morning my Bluetti was at 91% made coffee and it went all the way down to 69%
Charging via solar and it went from 75% to 100%
This is frustrating me because I have no clue what 100% charge actually is for each cell and would have a better idea what a true 100% charge is. It hasn’t really been a huge issue as far as functionality but sometimes I might be able to stay put longer without alternator charging.

Here is the bms data at “100%”

You definitely have an early AC200P from what your pics and firmware versions show. I think your case demonstrates the reason Bluetti eliminated the individual cell voltage from the data screens because it raised more questions that helped provide info. I do not personally know what the fully charged voltage of the LifePO4 cell (in the AC200P)should be at a 100% state of charge indicated. I do know the state of charge percentage is an approximation and not meter grade accurate.

Is your temperature less than room temperature and could be a cause of fluctuations in the SOC readings. (Low temps decrease battery capacity)?

If it were me, I would run your AC200P to zero and then fully charge back to 100%. At that point a capacity test could be performed by running an approx. 500 watt device (or a 750 watt electric heater) until you have the battery at zero percent again. If you have a killawatt meter that registers the true AC output that would be the best case.

You should see approximately 3 hours and 15 minutes run time with a 500 watt load if you are receiving normal battery capacity. This assumes that you are at room temperature and not in a cold environment. A cold environment will give you less capacity. If you are using a killawatt meter then I would expect to see 1600 to 1700 watt hours capacity in optimum conditions.

It is possible if you are in a cold environment that when you run a high load,(coffee) that your inverter warms up the A200P which will then register a different state of charge than expected after being warmed up.

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That all makes a lot of sense. It has been pretty chilly here in southern AZ. My van will be in the 40s to upper 50s in the morning. I’ll have to wait until I have a 4.5 hour drive to charge up from 0% or get a campsite with power.
Like i said, it operates fine. It’s been cloudy here as of lately and the other day I needed to drive to charge it but maybe could have stayed put if i had a better SOC reading.

Bluetti said they were going to send me another AC adapter with “adjusted voltage”?

Some of the AC200P chargers were not reaching the full voltage to fully charge the AC200P. This was indicated by the state of charge not being able to reach 100%. If your AC200P charger was reaching 100% then the voltage should be fine.

They sent me the 500watt charger a few months ago. Mine came with a 400 watt. The 500 watt sometimes will only charge to 75 or 85% and as soon as I plug solar panels into it, it hits 100%.

Why did they send you the 500 watt charger? Wad the 400 watt charger not working?

I just asked for the 500 watt because I had bought a second 400watt with adapter for the solar port and right after the 500 watt came out. my input is 900watts via AC charging