Best Sun Powerwall

[tecnodave]

I have just acquired a Best Sun Powerwall also known as a Fution battery. It is from China and is a sortaof clone of the Tesla Powerwall. I am looking for any info on the unit.


It is rated 10.24kwh battery pack
Inverter 5kw continuous / 10 kw surge            update.....4kw.cont 5ka/h
It has 16 ea. 200 a.h. LFP battery                    update  32 ea  100 a.h. pouch cell
BMS                                                                update   Daly 100 amp dumb
Inverter/charger
Power transfer relay
MPPT Controller

It appears to be assembled by Fution and sold by Best Sun Solar of China
It is very poorly engineered as it has 14 gauge wire on the input connectors and 15 amp connectors on a unit rated 60 amps.   Under sized wiring to battery cells etc.

The Inverter/charger looks familiar but I don’t remember where I have seen it.

I found a manual on diysolar  forum but no one who that has seen one.

Sold on Amazon for $3995.00

No I did not pay that for it, I consulted on it in a failed installation where it burned up the refrigerator, television and other items in the household.

It is 230 volt 45-65hz and not 120/240 U.S.A. Standard, not U.L. Listed, the reason it burned out the loads is obvious...it’s not split phase

The manufacturer posted that to use a 230 volt to 120 volt transformer but also stated that it is not suitable for inductive loads in a separate post to a prospective buyer on Amazon. Maybe i can find a capacitive transformer? LOL

It is very poorly engineered and seems to be assembled in China of off the shelf components. All wiring is undersized by N.E.C. standards. It is assembled in a very tinny outer shell, which bent and distorted when removed from the installation.

I advised the homeowner of his liability of using a non U.L. not N.E.C. compliant device in his million dollar house and that his homeowners insurance would by voided if the unit were to fail and burn down the house.  He decided he did not want that in his house with his wife and children and offered me the unit for my consultation fee. As an incurable tinkerer I accepted his offer.  So I have at the minimum a 200 a.h. 51.2 volt 10.24 kWh battery, with a BMS for my $200 diagnostic fee. Along with a charger/inverter that I recognize but can’t remember just who made it, probably will not use most of the electronics as I already have MidNite and MagnaSine , though I’m 24 volt now , a newer inverter is in the works.
I advised the owner of the unit of the hazards of using the unit and was offered the unit in exchange for my diagnostic fee.

[boB]

Interesting but not familiar with this one but have heard the name.

Sure doesn't look like it could have that much energy storage...

Sorry you burnt up appliances !

Curious what's inside of it though.

[Steve_S]

I have never heard of this brand / make at all.
If as you say, several components are below grade of what should be used, then break it apart, build a proper 16S 48V Battery Packs with decent BMS & fuse.  The SCC "IF" it has one can likely be reused as could the Inverter or even sold off as individual components.  Once you extra then and can see labels & markings, it would be easier to track down who made it and get docs.

If you goto the Lithium Section in the forum I have a couple of posts there including a Doc from Luyuan Tech that explains how to assemble and setup LFP packs.  Alternately you could come to DIYSolarForum and tap into a lot of us who are doing LFP Systems on various scales.

[Robin]

This type of product is on my wish list of projects. Bob has a unique design idea that would make it very competitive. Now all we need is to finish some of our current projects.

[Robin]

This type of product is on my wish list of projects. Bob has a unique design idea that would make it very competitive. Now all we need is to finish some of our current projects.

[tecnodave]

Hey thanks all for the responses, I had forgot that I posted here. I have much more detail on the unit in the battery category. The thing that stumps me is that they are “pouch cells” encased in plastic clamping frames. Have you ever seen 200 a.h. pouch cells? I sure haven’t, can’t find them on the internet. When I check the part number on internet it is listed on Alibaba as a 50 a.h. LFP pouch cell for electric vehicle use....This unit is rated 10,240 watt hours at 52.5 volts....that works out to 200 a.h. as claimed by the manufacturer.  There are many inconsistencies in the documentation that I don’t know to believe about this unit. More Chinese inflated claims? Unit is advertised as a “Chinese Tesla Powerwall”  the unit currently shown on Amazon is a later variant which has 32 pouch cells at the same rated capacity

[tecnodave]

boB, 

I didn’t lose anything in this deal, I was asked to look at this powerwall in a home that failed at installation. I got the whole deal just for knowing something about power that the contractor who installed this unit in a million dollar house sure as hell should have known....it’s 230 volt....NOT 120/240 volt split phase..charger worked fine, inverter had no neutral and the series string of appliances was unbalanced burning many items out......should have known that...state listened contractor....duh!

I spent an hour or two and got a big battery....now how to get it incorporated into my system.

Techno

[tecnodave]

I need to eat  some crow......they are not 200 amp pouches.....there are two in each frame, well hidden. The manufacturers data sheet states that this unit is 2P16S and i did verify that is the cell configuration is what they claim. Just looking at the cell banks it does look like there is only one cell in each frame.  I am not sure of the capacity as yet as the unit does not tell me much. I do have 240 volts in my shop space so i can charge it but i have no 230 volt loads of enough size to test it.

I really have no use for a chinese inverter charger so im going to break this unit down and salvage the cells to make two 24 volt sets and use my existing charge controllers , inverters and converters.

I like the Chargery system as being the most robust ive looked at.

The one thing i do not like about BMS’s is shutting off the battery connection for the SCC. I have smoked my very early kid controller several times by losing battery connection while producing power from solar, i do not know how to address that problem.

[boB]

Would love to see the insides of the inverter/charger section if it is in there

[tecnodave]

boB,

here are the guts....

[tecnodave]

bob,

i would bet that this unit is not made by bestsun, there is a label over the label, everything in this box was from somewhere else.  The BMS is the cheapest one on the chinese listings for the Daly, this one is all characters in Chinese

[tecnodave]

A few more shots with more wiring out of the way.  this assembly had an outer cover which was removed when this chassis was installed into the battery box.

[boB]

Thanks Dave !

Looks semi-familiar as sort of like another Taiwanese inverter/charger that I saw a few years ago.

Looks about right for a Made In China inverter.  They are getting TOO good at this !

[tecnodave]

bob,

yeah, ive seen this one before, I have a 48 volt inverter/charger in the junk pile, i think it is the same one, I will probably peel off the best sun sticker to see what is under there, I cant inagine that it is worth very much, the box has no front cover, this whole unit was mounted within the Fution with no front cover. The display was moved to the front cover on the Fution AKA Best Sun Powerwall.

Any offers for the unknown pedigree???

Im holding out for a Rosie.

[tecnodave]

Digging deeper

Is this box a           AXPERT 5KVA-48-PAR-B

from the label which was buried this was found on the internet, it appears that this is the inverter/charger

seems to be a match