BestSun Powerwall

[Tecnodave]

There are 4 stacks of 4 cells each all wired in series 48 volt system...terminal voltage 51.2 v.d.c.
The manual for the unit says 32 cells 2P16S but my unit is 16S

All my current stuff is 24 volts so I’m planning to make 2 banks. My electric needs are modest but I have dual systems for redundancy. Two Classic 150’s, two Kid’s, two good inverters, Exeltech XP-1100. and MagnaSine MS-4024 AE,
I have no POCO connection and rely on solar only.

 

[Tecnodave]

There is a BMS in there, it can be seen just above the main inverter/charger, looks like a DALY but all the characters are in Chinese , looks like it is 100 amp common bus unit.

 

[Tecnodave]

So to clear up about the damage done, it wasn’t my house and I don’t have all the details on that. I was hired by a state licensed contractor to analyze this installation failed on installation testing. I quickly discovered that the whole Fution powerwall is 230 volts in and out, NOT 120/240 volts as is standard in USA. The charger worked fine but during installation testing the unit burned out at least several appliances in the home. I am a retired electrical engineer who has spent an entire career in mission critical systems and often serve as a consultant to contractors and diy’ers. I did solar powered backup systems for communications engineering in the 1960-1970’s so have a vast breadth of knowledge in this arena.

 

[Bleedingblue]

So to clear up about the damage done, it wasn’t my house and I don’t have all the details on that. I was hired by a state licensed contractor to analyze this installation failed on installation testing. I quickly discovered that the whole Fution powerwall is 230 volts in and out, NOT 120/240 volts as is standard in USA. The charger worked fine but during installation testing the unit burned out at least several appliances in the home. I am a retired electrical engineer who has spent an entire career in mission critical systems and often serve as a consultant to contractors and diy’ers. I did solar powered backup systems for communications engineering in the 1960-1970’s so have a vast breadth of knowledge in this arena.

They needed to have a transformer. I use 240volt units with a 37.5kw transformer

 

[Tecnodave]

The owner of the million dollar house did not want it on any account after i has diagnosed the fault mode, Its Euro 230 volt CE certified, its not 120/240 volts , its not UL listed therefore his homeowners insurance was not valid in a claim......i got it for diagnosing the fault. Even adding an external device it still will not be UL listed. Do be aware that if you use electrical items that are not UL listed, you are in violation of the code....go look at your homeowners policy....its very clear, you have just handed them a escape clause....if you burn down your home likely you will recover nothing,

I’m licensed , i cannot afford to make the mistake of not advising the homeowner as to the consequences of what he is doing, the fault mode that i was contracted to find.

david

 

[NwCali]

I looked at these on Ebay.... Nice right up, maybe someone should do a YouTube review on them to let others know what they would be buying?

 

[Tecnodave]

Look deep down the ad, it states that these are made to order.......once order is placed you need to wait for it to be assembled.........john and freddies tinker shop.....searching there is only one name associated with the exact name of this operation

 

[Tecnodave]

They needed to have a transformer. I use 240volt units with a 37.5kw transformer

That is a huge inductive load for a 5 kw. inverter

 

[Bleedingblue]

That is a huge inductive load for a 5 kw. inverter

I use more than 1 and in the future will expanding from 4 units to 6. I also am going to use other units to just charge batteries up from panels mounted elsewhere.

Most of these units that are 230volt can be changed to 240 and 60 hertz in the settings.

 

[AgroVenturesPeru]

Thanks TechnoDave. We sure could use someone like you in this part of the world. There's not much quality down here.

 

[davesmcd]

This looks too good to be true-- the cost looks very low for the claimed capabilities. Anyone tried one yet?

Bestsun Powerwall

DO NOT PURCHASE THIS PRODUCT! IT COULD KILL YOU! I used this product for about 2 months when the overcharge protection failed causing the lithium batteries to swell and fill my house with toxic gas! It didn't even stop running, I had to manually shut it off and disconnect it to stop the gassing!

I contacted the company, who initially offered to repair and a partial refund. Now, they are refusing the partial refund which they offered! It took them 3 weeks to send a test video, which they want me to disassemble and test each of the lithium cells before they will do any type of part replacement. Unfortunately, I purchased this item in advance of getting my solar setup so I knew what was needed and the Amazon Return window is close.

Now I have a $4000 useless paperweight!

DO NOT DO BUSINESS WITH THIS COMPANY!

THEY WILL LIE TO YOU!

THEY WILL NOT HELP YOU WHEN THEIR PRODUCT FAILS!

 

[davesmcd]

I guess if you want a turn key, simple, sleek system not bad. It looks like the same mpp screen

DO NOT PURCHASE THIS PRODUCT! IT COULD KILL YOU! I used this product for about 2 months when the overcharge protection failed causing the lithium batteries to swell and fill my house with toxic gas! It didn't even stop running, I had to manually shut it off and disconnect it to stop the gassing!

I contacted the company, who initially offered to repair and a partial refund. Now, they are refusing the partial refund which they offered! It took them 3 weeks to send a test video, which they want me to disassemble and test each of the lithium cells before they will do any type of part replacement. Unfortunately, I purchased this item in advance of getting my solar setup so I knew what was needed and the Amazon Return window is close.

Now I have a $4000 useless paperweight!

DO NOT DO BUSINESS WITH THIS COMPANY!

THEY WILL LIE TO YOU!

THEY WILL NOT HELP YOU WHEN THEIR PRODUCT FAILS!

 

[davesmcd]

Yeah, I'm gonna pass on this unless and until I see some credible people telling me it's wonderful. Thanks!

DO NOT PURCHASE THIS PRODUCT! IT COULD KILL YOU! I used this product for about 2 months when the overcharge protection failed causing the lithium batteries to swell and fill my house with toxic gas! It didn't even stop running, I had to manually shut it off and disconnect it to stop the gassing!

I contacted the company, who initially offered to repair and a partial refund. Now, they are refusing the partial refund which they offered! It took them 3 weeks to send a test video, which they want me to disassemble and test each of the lithium cells before they will do any type of part replacement. Unfortunately, I purchased this item in advance of getting my solar setup so I knew what was needed and the Amazon Return window is close.

Now I have a $4000 useless paperweight!

DO NOT DO BUSINESS WITH THIS COMPANY!

THEY WILL LIE TO YOU!

THEY WILL NOT HELP YOU WHEN THEIR PRODUCT FAILS!

 

[davesmcd]

I just got one of these and am in the process of tearing into it. I have gleaned a few details so far which I will share here.
The unit contains 16 cells which do not look like any prismatic cells that I have ever seen, they are not encapsulated cells like the CALB cells that I am used to. They are aluminum foil wrapped cells much like the cells that you will find in Dell notebooks and Mac notebooks.
They are 230 volts in and out NOT 120/240 There is a combined inverter/charger. Also has a solar input, possibly MPPT controller. It contains a separate BMS. As yet maker undetermined as characters are in Chinese. There is a power transfer relay.
Something just came up,, I have much more to tell. I gotta go now but I will be back......Tecnodave.....

DO NOT PURCHASE THIS PRODUCT! IT COULD KILL YOU! I used this product for about 2 months when the overcharge protection failed causing the lithium batteries to swell and fill my house with toxic gas! It didn't even stop running, I had to manually shut it off and disconnect it to stop the gassing!

I contacted the company, who initially offered to repair and a partial refund. Now, they are refusing the partial refund which they offered! It took them 3 weeks to send a test video, which they want me to disassemble and test each of the lithium cells before they will do any type of part replacement. Unfortunately, I purchased this item in advance of getting my solar setup so I knew what was needed and the Amazon Return window is close.

Now I have a $4000 useless paperweight!

DO NOT DO BUSINESS WITH THIS COMPANY!

THEY WILL LIE TO YOU!

THEY WILL NOT HELP YOU WHEN THEIR PRODUCT FAILS!

 

[Tecnodave]

You found just what i did, I got mine from a new installation where it failed to do what it was sold to do on day one. I have scrapped the unit as a whole, the inverter/charger is a mpp unit, the batteries are unknowns, the BMS is the cheapest Daly i have seen on alibaba, the cells are surplus from some unknown, the main DC breaker is not rated for DC.....its for AC, they will burst into flames when tripping on fault current DC.....designer graduated from fart smeller university...

This is the only thing that was salvaged...

 

[davesmcd]

You found just what i did, I got mine from a new installation where it failed to do what it was sold to do on day one. I have scrapped the unit as a whole, the inverter/charger is a mpp unit, the batteries are unknowns, the BMS is the cheapest Daly i have seen on alibaba, the cells are surplus from some unknown, the main DC breaker is not rated for DC.....its for AC, they will burst into flames when tripping on fault current DC.....designer graduated from fart smeller university...

This is the only thing that was salvaged...

I purchased mine new from Amazon, biggest mistake I ever made. Really wish I had installed and used it within the Amazon refund window! It is now my life journey to make sure noone else wastes $4k on this garbage!

 

[Tecnodave]

I was asked by a home owner with this unit to analyze this unit that did not function as wanted. As a commercial electrician I must inform the client of the bad and ugly that i see, and when i looked it over and told him the obvious, its not legal here (in the US) and not safe as is. Its euro /asia style wiring and not compatible with North America Power I had to inform him that as a result of it not being listed as tested to UL standards and therefore not legal which automatically gives your insurance company a valid reason to deny a claim.

It was his decision to scrap the unit and i was offered it for my consulting fee.

I retired from American Industry so i know quality when i see it.

 

[Tecnodave]

What i think is more criminal than some guy in a garage shop in guangdong china bolting togather krap like this is a huge company like Amazon fronting this as if its legal here.. They avoid any liability for keerap by selling a storefront....they dont sell the product..This should not be sold in the US to anyone, I do not see any agency approval statements at all

 

[Tecnodave]

I purchased mine new from Amazon, biggest mistake I ever made. Really wish I had installed and used it within the Amazon refund window! It is now my life journey to make sure noone else wastes $4k on this garbage!

so what did you have to do with the remains of the unit and curious as to where you are located and how you dealt with 230 volts in and out

 

[shangribu]

Hello Tecnodave,
Your analysis is very helpful. I actually purchased the Fution Power Wall on Amazon last year and installed it on a 45 ft boat. Our mechanics/electrician used a 110/240 transformer to make it work. The power in is just taken from the grid directly for 240V. Because it is on a boat and is not being charged and discharged daily, it works for us so far. But we do have minor issues. I wonder whether you can offer your insights since you already took one apart. I will take all the precautions since I know this machine is not safe or UL listed. So I will not leave it being charged unattended and has to be vigilant on what is going on with the machine. Thank you.

 

[Tecnodave]

Hello Tecnodave,
Your analysis is very helpful. I actually purchased the Fution Power Wall on Amazon last year and installed it on a 45 ft boat. Our mechanics/electrician used a 110/240 transformer to make it work. The power in is just taken from the grid directly for 240V. Because it is on a boat and is not being charged and discharged daily, it works for us so far. But we do have minor issues. I wonder whether you can offer your insights since you already took one apart. I will take all the precautions since I know this machine is not safe or UL listed. So I will not leave it being charged unattended and has to be vigilant on what is going on with the machine. Thank you.

@shangribu

First look under the right bottom of the cabinet and you will see a white handled circuit breaker there labeled DC BREAKER check the label on that breaker, if it is the same as mine rated for 230 volts AC and NO rating for DC.

AC breakers are not designed for DC and will arc and burst into flames on a overload situation. This is extremely dangerous as all the power of the batteries will be shorted to arc in that breaker......A plain old fast blow fuse would be much better but a much better solution is a true DC rated breaker such as the MidNite Solar MNDC breaker which is really a Carlingswitch D series breaker, <EDIT Ancor Marine also is a Carlingswitch breaker rebranded > Just be sure rated for 72 volts or so....and rated for “DC”.....off shore sh** probably does not have a high enough rating. Many are 12/24 volt only.

OK That is what could burn you down.......change that breaker

On to the cells......I have never seen cells like this in a consumer product...They are aluminized plastic foil pouches, with no outer housing. I have pulled open a few dead LFP cells and they had several pouches like these but they were encased, in a glued plastic housing that can contain a ruptured cell, these are just the pouches with no containment.

Someone else posted in another thread that i have on this unit that speaks of a burst cell and the release of toxic gasses in a housing situation.

Not Good.......toxic gasses while you sleep anyone?

The BMS in the unit is the cheapest, wimpiest, Daly unit that i have ever seen, characters all in chinese

Do i wanna trust that?....

I scrapped my unit and will use the cells reconfigured for 24 volt to use with my existing system using better BMS’s and my existing charge controllers and inverter/charger.

 

[Tecnodave]

Look at the related thread “ Fution‘s 10 kw. powerwall clone” Its the same unit.

Not impressed at all with it, it was free so I am free to make what i want from it.

 

[shangribu]

Hello Tecnodave,
Thank you for all the advice. I have taken the photos of the inside of the machine. I am not an expert on this stuff so I don't know whether the machine I have has the wrong DC breakers. This is the only white breaker on the bottom of the machine. I know this breaker if turned "ON" is to supply the inverter with 240V power to charge the battery. So is this breaker for AC power? Why does it need to have DC rating?
Our electrician also put another 30 amp breaker outside of Fution so only when we turn the outside breaker on there is 240V power going to the Fution. When I turn this white breaker on, Fution would start charging the battery from the grid. I also took a video of the bottom of the breaker because the machine is mounted and there is limited space on the bottom the phone cannot focus well with the photo and the video is a bit blurry as well but the label can be read.

 

[Tecnodave]

The white breaker IS THE DC BATTERY BREAKER. It is not the AC input breaker, it is not rated for DC. It is rated for 230 volts AC.......IT IS NOT RATED FOR DC.....the wire coming from it goes directly to the battery....it is not in the AC input! It does not protect the input of the inverter, It DOES NOT SWITCH OFF THE AC.................

NOT IF AND OR BUTT....... AC BREAKERS BURST INTO FLAMES WHEN OVERLOADED ON DC


Pictures........#1 bottom of cabinet where the white DC BREAKER IS LOCATED
#2 the AC rated breaker used on the battery
#3 the AC breaker which is located on the lower left corner of the inverter/charger unit which is located on the right side of the unit. It is not accessable to the outside of the unit


A 30 amp breaker AC input breaker DOES NOT protect a 15 amp rated unit.......The proper breaker is a 15 amp 2 pole breaker


If you value your life and property change that breaker.......

 

[shangribu]

Thank you for the quick reply. I just try to understand how it works. When I turn this breaker on and if the breaker we have outside the Fution is "ON", the battery starts charging if there is the grid power in. How could this breaker go directly to the battery not the inverter?