Should I fully discharge upon receipt

Just received my EB3A. On the AC200Max and other ‘big boy’ forums many recommend initially discharging to ‘zero’ state of charge (knowing that the firmware does not let the battery fully go zero). Should this be also done on the EB3A?

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I charge mine to 100% then discharge to 0% then back to 100%. I would assume that might calibrate the BMS.

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I charge all my new units to 100% first followed by a complete battery drain to an indicated state of charge of 0% followed by a complete recharge.

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Thank you. I have now done this.

Newbie here. Why? What is the purpose of charge 100% down to 0% then back up to 100%

Thanks, Kenn

Supposedly to calibrate the battery management system so that 0 is actually 0% and 100 is actually 100%. I like to run mine down to 0 and then recharge to 100% but I think it just makes me feel better.

Thanks. I got mine today, upgraded the firmware and charged to 100%. on the way down now. I just wondered. Appreciate the reply.

Kenn

Would be nice if Bluetti gave such advise.

Probably not to worry about. Just would only use 1 cycle out of several thousand still available. The advantage of LIFEPO4 batteries.

I would expect, that the BMS was calibrated at the factory and then discharged to shipping perecentage (60%)

If the meter is showing zero but still running your appliance, then you would know BMS wasn’t calibrated. You then get your calibration without needing to do so manually.

If required, then I would assume the same logic would have to be used on every lithium LIFEPO4 battery you buy. I stand corrected, but I never read this from any manufacture of these batteries.

What say Bluetti, is it necessary?

Got this from a FAQ in a Bluetti advertisement for the EB200:

Q4: Why should I deplete the battery first and recharge it to 100% when I receive the new product?

A: In this way, you can re-calibrate the State of Charge system to reflect actual charge and prevent unusual battery discharge.

This should be done at the factory. It would be called Quality Control.

Over time and use, it may require to recalibrate, as cells tolerances can change. Especially if cell quality is not A, but B class due to supply shortages?. A bad cell develops?

Perhaps BMS currently in use has a bug? Unusual battery discharge?

With firmware update may fix it, but requires recalibration.

Another possiblility of needing to recalibrate, is the shunt wasn’t set up and sold that way.

Usually this would be require if shunt was disconnected from the system, which would not be the case with AC200MAX. (all internal)

There is a bit of math involved in tracking charge/current percentage and over time, the math can be off which would need to be recalibrated. Perhaps their formula in the firmware is not precise or rough math.

It is disappointing that I can no longer view the individual cell voltage.

Why was this feature removed in an update. It was one reason I got this unit for the diagnostic features. I would like to have this feature back asap.

Is there a recommended way to discharge to 0%? Leave the internal LED light running until 0%?

One could put it to use instead of just draining the battery. If not in a hurry, run a fan or something that uses about 100 to 200 watt. I wouldn’t do a heavy discharge.

LIFEPO4 will last much longer, if one never goes below 10 percent and if practical charge up to 90 percent at most.

If you find that your display is inaccurate often, then there is an issue with the unit. One should not have to recalibrate every month or more. Something is wrong or bad firmware bug.

Being able to see the individual cell voltage/state would be a nice diagnostic tool to have.

Bluetti can you return that feature, eh?

The EB200 still has it, but it’s hidden. You have to tap the upper LH corner of the BMS Maintenance display about 4-5 times quickly to see the cell readouts.

Thank-You for that tip. It worked!. Happy camper…

Individual cells showing 7 x 3.34 and 8 x 3.33 and Cell 11 reading 3.37.
Temp 23 to 24.

Look like the cell are not fully balanced.