AC200Max with B300k, different rate of discharge?

[billybobster]

I recently added a B300K to up my capacity with my AC200Max. Plan to use it in a campervan. I have it set up in my shop running some led string lights just to see how it behaves. Both batteries were at full charge, so I decided to run them down for storage. The 200max battery was drawing down a lot faster. It got down to 1% charge, while the 300K was at 29%. Is that how it’s supposed to work? Will the 200max shut down before the 300K is fully discharged? If that’s the case, about 1/3 of the 300k capacity will be unusable. I assumed that the batteries would discharge evenly…

[Selfmadestrom]

Hi @billybobster

The battery should discharge evenly to a certain level. There will be always some percent off each other. But 28% is a huge gap. Did you try to calibrate both battery packs?

I just assume that on of the B300K doesnt show the right capacity and may have less energy stored than the other one.

greetings
Erik

[jockel66]

See you here, the same problem.

B230 discharging much faster than AC200Max

I have one B230 connected to an AC200Max, which I’ve been running for ~2 years. The manual states that the discharging sequence will pull alternately from B230 or AC200Max depending on which has higher charge, to keep all batteries at about the same charge level – but I’m no longer seeing this equalization occur. In the past few months the B230 has been discharging much faster than AC200Max: After a few hours of no solar (at night), I might see AC200Max at 60% , and B230 at 30%. Obviously, th…

[BLUETTI_CARE]

Hi @billybobster, Could you please share the SN code and current firmware version of your AC200MAX? Specifically, we need to confirm whether your BMS firmware is updated to the latest version.

Thank you, @Selfmadestrom and @jockel66, for your assistance and suggestions. Yes, recalibration can be very helpful in resolving this issue.

[billybobster]

[BLUETTI_CARE]

Hi @billybobster, Please click “Next” on the AC200MAX screen to find the BMS version for the B300K, or log into the Bluetti app to locate the corresponding information.

Once we have this, we will send you the new firmware.

By the way, please note that if you need my assistance, please @BLUETTI_CARE, otherwise, I might not see your message and be able to help you promptly.

[billybobster]

[billybobster]

questions for you:

1. The 200Max - 300K connected together. Discharged to 1% and 30% respectively. Can I continue to discharge or will the 200Max go to zero and shut down?
2. I have never been successful doing a firmware upgrade to the 200Max. It goes to about 90% and then errors out, leaving the fan running at full speed. I am forced to restart the 200max to get it working. Why does the upgrade not work?

Thanks!

[BLUETTI_CARE]

Hi @billybobster, We noticed that your B300K is already on the latest version.
We’ve pushed BMS v1010.12 to your AC200MAX. Please try upgrading it. During the upgrade process, ensure no loads are connected, and disconnect the B300K as well.

Yes, for recalibration, the battery needs to be discharged to 0%.

To successfully complete the upgrade, please follow these troubleshooting steps:

1. Update the Bluetti app to the latest version.
2. Clear the app cache and try again. If unsuccessful, uninstall the app and reinstall it.
3. Try upgrading using a different phone, preferably an Android device.
4. Keep your phone close to the AC200MAX during the upgrade.
5. Set the AC200MAX screen timeout to “Never.”
6. If you’re upgrading via Wi-Fi, disconnect it and use mobile data, or restart your Wi-Fi and try again.

Does this help?

[billybobster]

BMS upgrade successful!

DSP upgrade failed twice after following instructions above. Maybe that DSP
upgrade is not critical.

[BLUETTI_CARE]

Hi @billybobster, Thank you for letting us know.
We’re glad to hear that the BMS upgrade was successful. Upgrading the BMS firmware helps optimize SOC balance and charging/discharging performance.

For this kind of issue, upgrading the DSP is not very meaningful. If you’re unable to upgrade the DSP, that’s okay.

[Thari]

As far as your question about drawdown not being evenly distributed: it looks like it was. The Max has 2048Wh and the B300 has 2764Wh. When the Max hits 1%, the B300K should be about 29% (about 800Wh) left, well within the starting SOC variance and the efficiency variance of the 2 units (one being older than the other).

[Liberty]

Hello billybobster : I am not knit picking here, but I use the AC200MAX with the B300 and or B230 no problems.
As I understand, the B300k isn’t recommended in the AC200MAX manual.
Maybe that is part of the issue.
B

[billybobster]

Per Bluetti:

" The B300K is designed to perfectly complement the following BLUETTI models: AC200L, AC200MAX, AC300, and AC500 . Seamlessly integrate the B300K with your favorite BLUETTI power stations to ensure an uninterrupted power supply for your devices."