I agree with your assessment: for larger batteries, I will absolutely avoid Bluetti as long as they refuse to support local or DIY repair of their products. This is unfortunate - I was planning to purchase a large one in the next 12 months or so, likely a Bluetti as I had been quite happy with their products until this experience.
Instead, I plan to build with separate components as you described.
As for my AC200P, I don’t know that I’ll take it much farther than the picture I shared above. The 48V aftermarket inverter is working fine. I don’t have the fancy screen or other gadgets, but I also don’t really care about them. My daughter and I have enjoyed this project, so I might install an aftermarket BMS at some point - it looks like there are some solder-points that are fairly accessible for the individual BMS leads.
I really just have too many other projects on my plate to tackle an in-depth inverter board repair, although I admire your enthusiasm! The glue on this board is a serious pain. I checked for obvious things, like bulging capacitors or scorch marks - no clues.
This is the inverter I installed: Amazon.com: WZRELB 2000W Pure Sine Wave Inverter 48V DC to 110V 120V AC Power Converter with LED Display, Off-Grid Portable Power Inverter with 4 AC Outlets for Home, RV, Truck, Camping
That inverter is a pretty good value, and I see further up that the charging system still works independently of the inverter, which is pretty cool. Have you checked whether the MPPT works?
My feeling regarding the 100v2 is that it was an expenditure comparable to a mid-range mobile phone, so if it lasts 5 years that isn’t too bad. But a full sized system is more like a car and I would expect to be able to keep maintaining it as long as I want. AC200P and 200v2 are maybe sort of in between. The cutover might be at a box weighing 70 lb or more, since that has to be shipped by freight, while UPS and Fedex will take packages up to 70 lb.
Bluetti’s rationalization for not having repair documentation or parts availability is pretty weak, considering that people fix their own cars all the time, and TV repair was once a thriving local industry. TV’s back then had CRT’s with as much as 20,000 volts from the flyback coil. Similar with power tools, home wiring, etc. I’m much more scared of a gasoline powered chain saw than I am of an inverter board…
Now I’m wondering if I have to pay the shipping costs if someday I need a 100v2 warranty repair. Hmm.
Can I ask what they wanted to charge you to repair your 200P?
I see someone on DIYSF has a 200P with some solar panels for sale. I’m not looking for anything like that but the offer seemed generally reasonable, depending on the warranty situation. The unavailability of repair info certainly damages the aftermarket for out of warranty units.
I am operating under the assumption that the inverter board handled MPPT. Both of the charging ports were routed through the inverter board. I was able to bypass it for the 56V DC input from the charger and connect that right to the BMS, but I don’t see any circuitry on the BMS that would suggest that it is capable of MPPT. That function of the inverter board won’t work either, because it routes that power through the same terminals that are currently shorted.
100% agree. It seems more like a marketing/sales-oriented decision than a customer-satisfaction decision.
They wouldn’t tell me until I shipped it to them. That’s a pretty hefty expense to pay just to find how much more it will cost to repair it - which was a big part of why I declined.
Time on even their extended warranty is ticking away for this model, so I wouldn’t spend much on it unless I was ready and willing to install aftermarket circuitry. If the battery fails, it’s probably not worth even a DIY repair because you’d have to replace the battery, BMS and inverter. At that point you might as well just buy a new unit, or build your own.
Inverter and MPPT are usually separate devices when you buy components, but Bluetti may have combined them on the same board as an optimization. In that case maybe you have no MPPT. On the other hand you have a 2000W 48V inverter, an AC charger, and 2 KWH of batteries. The batteries are good for a lot of cycles and don’t seem likely to fail, so if the charger holds up and if you don’t care about solar, then you have a decent power bank. You can always DIY something later, using whatever works from the existing parts.
Gonna add, if you have already managed to disconnect the battery pack, I wonderif Bluetti would let you send either just the inverter board, or else the whole unit but minus the batteries, which would save a lot of weight.