500Ah LiFePO4 and Unicorns

[HGPilot]

Good Morning Builders and Tinkerers!

I would like to resurrect some old threads about 500 Ah batteries (pics below) from Ali @ Unit price: 175USD now.
Has anyone tried these before?

For Solar System Energy Storage Car 3.2v 500ah Lifepo4 Battery Cell 3.2v300ah Battery Cell - Buy Lifepo4 Battery Cell lifepo4 500ah 3.2v 500ah Lifepo4 Battery Cell Product on Alibaba.com

For Solar System Energy Storage Car 3.2v 500ah Lifepo4 Battery Cell 3.2v300ah Battery Cell - Buy Lifepo4 Battery Cell lifepo4 500ah 3.2v 500ah Lifepo4 Battery Cell Product on Alibaba.com

www.alibaba.com

Thank You All!

A

 

[upnorthandpersonal]

It sounds way too good to be true. Also, the title of the product mentions both 500Ah and 300Ah...
Aliexpress for battery cells is more miss than hit as well.

 

[Steve_S]

There are companies like Winston that make cells up to 1000AH and SinoPoly makes up to 400AH and Higher AH on Spec.
The advert you show appears to be Sinopoly Cells (they are quite unique like Winstons) and their Max is 400AH.
The Blue Links above goto Manufacturer Sites.

NOTE that many of these were USED in Busses & other heavier EV's within China for the past 5+ years and are now cycling into the used supply lines. Also be aware that VERY FEW Companies make LFP Cells which are encased in ABS Plastic, CALB is one other that does so (they are white or cream in colour) Calb also produces Aluminium Cased Bluey's as well.

NOTE that Winstons, Sino's have Higher C-Rates and I believe they are all Yttrium Doped as well for cold temp operations to -20C, This is of course $$$$. There NO SUCH THING AS CHEAP Winstons or Sino's !

Sinopoly SP-LFP500AHA Source: https://evlithium.com/LiFePO4-Battery/164.html

Capacity	500Ah
Nominal Voltage	3.2V
Cut-off Voltage (discharge)	2.8V
Cut-off Voltage (charge)	3.8V
Max. charge current	3C
Max. discharge current (constant)	3C
Max. discharge current (Impulse 10S)	5C
Dimensions	71 x 451 x 285mm
Weight	35lbs (16kg)
Cycle life	80% DOD > 2000 Charges 70% DOD > 3000 Charges

 

[anschluss]

It is not impossible although the advertised price looks a bit low. They look like Sinopoly cells:

Sinopoly-500Ah.pdf (mylithiumbattery.com)

I have no actual experience, but a plausible explanation for the low price could be that the product description line

"for solar system energy storage car 3.2v 500ah lifepo4 battery cell 3.2v300ah battery cell"

is short hand for:

"Used car batteries with original 500ah capacity for solar storage. Expected remaining capacity may be as low as 300ah, but could be higher. You get what you pay for, or less."

If you look on alibaba.com for "Sinopoly 500ah" you can find results from perhaps more reputable dealers like this:

Prismatic Lithium Lifepo4 Battery 3.2v 500ah Deep Cycle Battery Cell For Solar System - Buy 500ah Battery,500ah Lifepo4,12v 500ah Battery Product on Alibaba.com

There, the advertised price is USD 260.- at which point I would perhaps rather consider two 270-320 Ah aluminum cased cells in parallel that are often mentioned on this forum (EVE, CATL, CALB, REPT, Lishen, Ganfeng). From looking at the Sinopoly specifications, it looks as if their cells are more geared towards vehicle use. The linked PDF mentions a 3C constant current discharge rate but a slightly lower cycle count of 2000 at 80% depth of discharge.

 

[HGPilot]

Thank You Everyone, very informative answers!
Will follow your advice and stick with 304s then.
Appreciate your insight!

A

 

[chrisski]

My initial thoughts is that the battery would not be as big as advertised, but looking at weight, a 8 S 500 ah pack of these batteries weigh in at 250 LBS, and my 2 X 8 S 560 ah total EVEs weigh in at 200 LBS, so just judging by weight, the batteries could provide the power advertised.

The 500 AH Cell specs from the wensite:

 

[Steve_S]

@HGPilot keep in mind one other thing, these buggers are HEAVY !
An EVE 280AH Cells weighs in at 5kg/11Lbs each cell. EVE 304's weigh 5.6/12.3 Lbs each.
It adds up fast and add case, bms, wires and it gets heavy.

 

[raurre]

Thank You Everyone, very informative answers!
Will follow your advice and stick with 304s then.
Appreciate your insight!

A

I saw where you commented about building your system with LV6548 and eve 304 batteries. I just built that exact system if your interested. I posted the pictures on show and tell.

 

[HGPilot]

I saw where you commented about building your system with LV6548 and eve 304 batteries. I just built that exact system if your interested. I posted the pictures on show and tell.

Your professionalism is showing and I am sure we are going to have many conversation in a near future
I really like how you got the batteries inside a metal enclosure as you never know what can go wrong with so much of stored energy...

Few questions if you don't mind:
- When compressing the pack, how did you calculate the pressure with those 4 springs? How much force are you using there?
- Whom did you buy those batteries from and were you happy with them?
- Do you run a gas generator or the grid? What do you switch with your transfer switch?
- Any advice on Neutral to Ground bonding in an off grid setup where your generator has to be bonded to ground and the main panel as well, how all of that integrates with the inverter with and without generator running?

As for Solar panels you have to watch out for 2 things (in order of importance) 1. Voc and 2. Impp.
The Voc voltage gets higher the colder it becomes so something that works well in the summer can be over the Voc limit in the winter when the panels become more efficient. I live in Canada and it gets coooold here so I leave a 20 to 25% Voc room below the 250V max of the inverter.
As a hack you could disconnect 1 panel from each string in the winter just to be on the safe side but it has it's issues too. Inverter can be damaged if Voc voltage is to exceed and your panels have Voc of 85.6 V so 2S is unfortunately a maximum.

As for current Impp the manual says 18 Amp max but it was revised unofficially to NO more than 22 as around 25 is when it will quit for good AFAIK...
Since your panels come up to 6Amp 4P setup would potentially take them up to 24 on a sunny day and this is something I wouldn't be comfortable with myself. I have seen Amps being clipped by the inverter at about 17.5 Amps. It would probably sacrifice production anyways but for safety I go with 2S3P x 4 setup for a total of 12 and max 5220 Watts. This is my logic but I could be wrong obviously.

Thanks,

A

 

[tanderson22]

It sounds way too good to be true. Also, the title of the product mentions both 500Ah and 300Ah...
Aliexpress for battery cells is more miss than hit as well.

I messaged them and they say they are selling both 300 ah and 500 ah cells.

 

[upnorthandpersonal]

If you decide to give it a try (which I still don't recommend), let us know what you get! I would love to be wrong on this one...

 

[Thingol]

If you decide to give it a try (which I still don't recommend), let us know what you get! I would love to be wrong on this one...

I am looking at these ones here to expand my storage-what do you think? There doesn't seem to be much user feedback out here on all these 400-500ah cells : https://www.alibaba.com/product-det...00337159436.html?spm=a2700.9114905.0.0.MWNROo

 

[houseofancients]

check with jenny before ordering , last time i checked with her, she told me these were used cells

 

[Thingol]

check with jenny before ordering , last time i checked with her, she told me these were used cells

I spoke to the current contact person on their Alibaba page (Daisy) and they told me that these were no longer in stock. Is there any reason to shun used cells, especially if they have been tested and the IR+capacity are good and matched?

I would not mind used cells that are well tested and documented-like those sold by Amy at Shenzen Luyuan. These ones though from Docan, would have been a dream if the indicated price, IR and capacity are correct...