AC200MAX and external lithium batteries

Is it possible to hook up an external Lithium Ion Phosphate battery to the AC200MAX? As in lets say 4 to 6 Zooms 12V 200Ah LiFePO4 Batteries, hooked in parallel and then hooked to the MAX? Is it possible & how would you hook those batteries to the MAX?

Not sure what a zoom is. You can could wire the batteries in series to get 24 volts or just buy 24 volt batteries and them feed the output to the Bluetti just like you would if you were car charging. This would give you around 200 watts of input.

Another way to go would be to purchase a dc step up converter which would convert 12 or 24 volts to 48 volts or more to obtain around a 500 watt rate of charge to the Bluetti.

ok, I was looking for more of a way to up my battery storage of the Bluetti Max instead of buying their B300 external battery.
the zooms brand is just a brand of Lithium Ion Phosphate battery.
So when you hook up the two external batteries from Bluetti, you now have 6000 extra watt hours of run time.
I just thought that maybe I could use another cheaper lithium ion phosphate battery, like the 12 volt 200 ah batteries which are about 2500 watts each. Wire them in parallel & have about 12,000 watts of battery storage. Wiring in parallel though would keep them at 12.8 volts though.

I purchased an external 48V LFP battery, then using the Bluetti DC enhancer plugging it in to the typical AC charge port and I can charge my AC200 Max with almost 500W. I have it set up so during night time, a timer/switch enables the DC power from the external battery to charge the AC200 for a few hours. During daytime a small MPPT controller with 750W of PV panels charge the external battery again.

I basically use this extra energy source to extend the AC200 Max operation as I more or less run everything in my house through the Max and it sometimes run short before the sun rises in the morning. This solution works very well.


You want the higher voltage available from wiring in series so you can increase your charge input watts. As Coz is stating above, you could wire four 12 volt batteries in series for 48 (50) volts of input to the Bluetti Charge enhancer and receive around a 500 watt input charge rate.

The type and size of the battery does not matter as the Bluetti only recognizes voltage and not the source. When you wire in Parallel, you are limiting your wattage input severely and need to increase voltage to increase the wattage input.

So if I purchased eg a 5kWh 48V LiFePO4 battery, would I connect this via what the manual calls the ‘Lead Acid battery charging clamp’ ?

Am I correct in saying that the only way to recharge this non-Bluetti expansion battery is via an external charger (not the AC200Max) ?

Yes you would need an external charger. I am not sure of the amperage that you can attach to the input side of the AC200 max and it may be best to put a DC to DC charger between the two to limit the amperage. The Lead acid battery charging clamp is only designed for low wattage charging.

That is what I figured. The only way to actually expand the battery backup for the MAX & increase its Watt hours is to buy 1 or 2 of the B240 or B300 Bluetti batteries that hook up to the special ports on the MAX.

Does anyone know how many B300 Bluetti expansion batteries can be hooked up to the AC200MAX?

Manual says 2 B230 or 2 B300

Not sure if it will let you mix and match :slight_smile:

The manual is an amazing vessel of information.

Thanks Scott: yes it is.
I just was hoping that with the B300, being it has 2 external battery connectors on each one & they can act as a pass through, or as they can hook up to each other and then the AC300, that they would maybe do the same for the AC200MAX. You know, if you look at the pictures of the AC300, it will show 2 batteries plugged into another 2 batteries & those batteries plugged into the AC300. Was hoping you could buy 4 B300 batteries & do the same with the AC200 MAX being it also has 2 external battery inputs. I did not find anything in the manual pertaining to that.

I have been emailing Bluetti on this and other subjects, but they have not been answering lately, so I just threw it out here on the community.

When the AC200MAX has the expansion batteries hooked up & they are drained to zero, the MAX shuts down the expansion batteries. When the solar starts charging again, it only charges the main MAX unit & does not wake up the expansion batteries, so it does not charge them. In order to wake them up, you have to start to charge them with the AC input until they wake up. Then they will start to charge from solar. Bluetti said they would solve this problem with a firmware update. Did they ever do this?