Cabin setup (Bluetti AC200Max + 48v rack battery)

[Andrewr05]

At our family cabin we have a Bluetti that runs basically everything we need.

But this week we added in a 48v rack battery into the setup and a charge controller and will soon be adding more solar panels.

Current setup-
Bluetti AC200Max (wired up to AC plugs throughout the cabin as well as DC lighting)
DC House 48V 50Ah (plugged into the PV input of the Bluetti)
Victron 150/35
(2x) EcoWorthy 195W solar panels

Now that we have a good charge controller, we are looking at getting some larger solar panels as these "200W" panels are now inadequate. (they're also cracked, as we had them improperly mounted and a huge windstorm came in and blew them over)

This should basically indefinitely keep us going up here once we get about 1,000W+ of solar panels installed

 

[Andrewr05]

And if anyone's curious, the cabins up on a mountain and this 'ol girl made it up there just fine.

 

[CTS]

We have a cabin in Manitoba that has no hydro near by so we currently run only on a 2000w Honda Generator, the cabin is wired as a typical house would be and it seems to work just fine.

I have been pricing and planning a system and its going to be an easy 10k by the time I'm done if not more.....a part of me just wants to go the solar generator route and use the Honda to charge it up.

 

[Andrewr05]

We have a cabin in Manitoba that has no hydro near by so we currently run only on a 2000w Honda Generator, the cabin is wired as a typical house would be and it seems to work just fine.

I have been pricing and planning a system and its going to be an easy 10k by the time I'm done if not more.....a part of me just wants to go the solar generator route and use the Honda to charge it up.

If you don't require a huge amount of power, a solar generator is a decent choice.

But once you go past a certain amount of power usage/requirement they start to get more expensive for what they do.

If I could go back in time I probably wouldn't do what I'm currently doing, I would've just saved up and home the separate component route, but this is working fine for us so far regardless.

 

[Andrewr05]

What would y'all recommended that I do in this specific situation to keep the Bluetti from fully draining the external battery?

The Bluetti is basically ignoring it's internal battery and constantly pulling power out of the external battery whenever it drops down to 98%.
(which means that it will fully eat all 2500Wh of the external battery before the Bluetti even drops to 97%; assuming the load we're drawing doesn't exceed the 850W input)

I don't believe the Bluetti has any options to only take in PV current past a certain percentage of SOC.

And because the Bluetti is making the assumption that the power coming in is from solar panels, it has no reason to cut it off at any certain voltage point either.

Is there an external low voltage cut off circuit I could wire in line between the rack battery and the Bluetti that would stop it from being it down to "zero" percent SOC?

Obviously the batteries have a BMS, but presumably it's not a good idea for the battery to be drained a right to the low voltage cut off point at which the BMS shuts off every time.

Any recommendations on what to do here?

Also... This is all speculative, I don't foresee us ever putting such a high load onto the Bluetti that it draws 2Kw just sitting there while we're away from the cabin.

But I still want some sort of protection for this happening.

 

[Andrewr05]

It looks like I'm going to get something like this
Victron BP 48V

Anyone have any lower cost alternatives?

 

[MrThisIsME]

If I reading correctly that you only currently have a 50ah battery @ 48v, not seeing adding more panels would do that much.
Not the answer you want to hear, but sounds like you are trying to band aid the Bluetti into something it were not. If it were me, sell it on Market Place and buy a proper solution (not expensive one).

 

[mptx]

It looks like I'm going to get something like this
Victron BP 48V

Anyone have any lower cost alternatives?

I was just going to recommend one of those.

 

[mptx]

If you don't require a huge amount of power, a solar generator is a decent choice.

But once you go past a certain amount of power usage/requirement they start to get more expensive for what they do.

If I could go back in time I probably wouldn't do what I'm currently doing, I would've just saved up and home the separate component route, but this is working fine for us so far regardless.

I have the AC200MAX as well. It serves us as emergency backup for refrigeration mostly but sits idle most of the time. Since you have one already it makes sense to put it to work.

 

[Andrewr05]

If I reading correctly that you only currently have a 50ah battery @ 48v, not seeing adding more panels would do that much.

Well, 360W (about what's the two 195W panels max out at) of solar panels doesn't even cover the cost of what we use in one day if we have a few people up there and we're making 57 cups of coffee with the Keurig all day lol

... sounds like you are trying to band aid the Bluetti into something it were not. If it were me, sell it on Market Place and buy a proper solution (not expensive one).

I honestly agree, but it's not up to me.

It's at our family cabin and we want it as relatively hands free for people that come up and want to just turn the unit on and have power.

I tried to push it more towards a separate component setup or an AIO like a 3K Growatt, but the initial cheaper route with the Bluetti was enticing.

I honestly think at some point I will go that route.
That is why when my dad said he wanted more capacity for this Bluetti that I originally went with the 48v rack battery, because I knew that it would ease the transition to a standalone system.