Author Topic: Best Sun Powerwall  (Read 84 times)


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Best Sun Powerwall
« on: March 23, 2021, 02:33:54 AM »
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
It has 16 ea. 200 a.h. LFP battery
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’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.
#1 Classic 150 12 x Sharp NE-170, 2S6P, 24volt L-16 Rolls-Surette S-530, MS4024 & Cotek ,  C-40 dirv.cont. for hot water
#2 Classic 150 12 x Sharp NE-170, 2S6P, 24 volt L-16 Interstate,Brutus Inv.
#3 Kid/WBjr 4/6 Sanyo 200 watt multilayer 4/6 P
#4 Kid/WBjr 4/6 Sanyo 200 watt multilayer 2S 2/3 P


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Re: Best Sun Powerwall
« Reply #1 on: March 23, 2021, 11:28:17 AM »
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.



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Re: Best Sun Powerwall
« Reply #2 on: March 25, 2021, 03:32:40 PM »
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.
Classic-200, Samlex EVO-4024 Inverter/Charger, 2080W of Canadian Solar CS-260P in 2 strings of 4.  856Ah of Rolls Surette LEAD _and_ 910AH of LiFePO4.