AC300 and other; Hot-plugging batteries?

Searching the forum did not reveal any information about hot-plugging.

Simple question therefore:

Is it possible and allowed to hot-add or hot-remove a battery pack (B300 or B300s) to or from a running AC300 / AC500? Maybe as long as at least one battery remains connected?

I first purchased the AC300 system together with a B300 battery.

Later I added 4 rigid solar panels (no step-down converter, raw power values are close to perfect for the AC300 as they are).

Now I got a second B300.

Can I just connect it or do I have to shut down the existing equipment?

You can hot swap existing batteries no problem. If I remember right its recommended to add a new battery by itself so it can be fully charged, then fully discharged and then fully charged again without any devices connected so the new battery BMS can be calibrated. Also check for firmware updates beforehand. I doubt skipping all the above and just adding the battery will hurt anything, but the BMS may not calculate the displayed percentage of charge correctly.

Hi Eric,

thanks for your respose. Good to know.

Well, I think I’ll play it safe then and do a complete system shutdown of all energy consumers (90+% IT equipment) and change the battery configuration afterwards.

Good hint regarding battery calibration. Also I can confirm a BMS fw update would indeed trigger a complete system reboot anyway - already had that once. Of couse I don’t know yet what BMS fw is installed on the new battery from the factory.

Yours
Mark

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As soon as the new B300 is added, the AC300 can display the BMS version on it. You have to access the AC300 with Bluetooth to update the BMS firmware.

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@mas1701 No need to turn off the device; just plug it in directly.

From what I understand, it’s generally recommended to shut down the AC300 or AC500 before adding or removing battery packs like the B300 or B300s. Hot-plugging could potentially cause damage or malfunctions, so it’s wise to follow the manufacturer’s guidelines closely. For specific instructions, consulting the user manual or contacting the manufacturer directly is a good approach. As we handle such tasks, may Allah grant us the wisdom and patience to manage our equipment safely and effectively.

Thanks for confirmation.

I had to power down anyway after all:
A BMS firmware upgrade only works with a single connected battery (App refuses otherwise). After the update, a restart is forced. Had this the second time already.

But as you have stated correctly, connecting and disconnecting on the fly works. For operational safety, I tried this when AC-out and DC-out were both switched off.

Intentionally, I connected both B300 batteries not before both had a similar SoC.

Yes. When upgrading the firmware, the machine will restart. When upgrading the BMS, the app will also prompt you to connect each battery pack for the upgrade one by one.