I'm just posting this as info for anyone else that might be looking for data.
I'm building an off-grid home soon and I'll have a 50kWh lifepo4 battery charged only from solar.
You can buy off the shelf battery systems here in Australia, about the best deal I can find costs $5500 for a 10kW pack with 200Ah cells installed.
So if I use these packs it is around $27500 for the house battery.
I love electronics and writing software and so the idea of just building the battery myself is more attractive that buying an off the shelf unit.
Looking around about the cheapest cells I can get are the Varicore 280Ah from the MEIBrand store. These are only $150AUD ($111 USD) delivered!
Looking at the photos I guessed they are really Lishen cells and that they are second life from looking at the terminals and messy laser welding.
So the Lishen was a 272Ah to start, I know they often test higher for the first few tests but they settle down eventually.
I ordered 16 cells for $2396AUD on September the 4th. This was the whole price including delivery and import duties.
My cells arrived on October 22nd.
The cells were really well packaged in large cardboard boxes and surrounded by thick custom made foam.
The cells could not have been damaged by normal transport.
I visually inspected each cell and weighed it and they were all 5.2kg +-140g
The cells are all clean and undamaged. If you lift the black cover on top you can see where the original serial has been scratched off.
The new terminals are laser welded on you can see where the old ones were ground off. The welding is B grade.
I tested the MR of each cell and they were all pretty close.
I checked the voltages and they were all close to 3.2v.
I selected the cell with the highest IR and ran a full charge to 3.65v and then a discharge to 2.5v on my EBC-A20 and the cell delivered 255Ah
I'll test them all eventually, but I was expecting this to be the worst cell due to the IR and so it was my baseline.
So these cells look to be down about 10% from new capacity, that equates to about 1500 cycles old.
I asked around and I found a guy who thinks that if you are lucky many of these cells came out of large UPS that may have spent most of the time fully charged.
He said if you were unlucky they may have come out of a bus and been worked very hard.
From the science i can find, lifepo4 batteries that have been cycled very lightly or kept mostly full can recover 10% when they are put through several full charge/discharge cycles and so those UPS batteries have the potential to actually improve initially!
Anyway, so it works out like this:
MEI Varicore 280Ah re-lifed Lishen 272Ah
Tests as 255Ah
Cost delivered of $150AUD per unit
Cost 59 Cents per Ah
Cost 18 Cents per Wh
So if I build my battery from these cells I get a 13kWh battery for $2400 (cells) plus $500 for the BMS/Cables and box.
So that means a 50kWh battery will cost me $11600 to build myself.
I've been buying from China for decades and I've dealt with many different factories and intermediates.
When you import something yourself you take a risk, I have seen guys in a freight company playing football with packages. I have seen guys in distribution centers open boxes and replace items with bricks or counterfeit items.
There is always the chance that you might not get what you expected. I always consider that I am self insuring myself with the lower price.
When I can I take out insurance on any shipment, but I always pay with either PayPal or a Credit card so that if I get ripped off I can (probably) get (most) of my money back.
I'm not suggesting this is the way anyone should go, you can buy quality brand new cells from Amy for about 39% more, and you won't have to worry about testing and balancing them or adding a BMS etc.
In my solar system the cells will likely never see more than 50amp discharge rates as I'll have 4 48v packs in parallel (each with it's own BMS) and the charge rates will be much lower. I'm going to limit the usage to the 80% of capacity which gives me the 40kWh that I think should be more than enough.
By doing this I would expect these cells to last a really long time.
I'm still planning to buy most of my cells new from Amy, but I think I'm quite happy with this purchase.
I know someone is going to say "But dude you bought 280Ah and you got 250Ah so you got ripped off" but personally I find it hard to feel ripped off when I got 13kWh of batteries for $2400 ;-).
I'm building an off-grid home soon and I'll have a 50kWh lifepo4 battery charged only from solar.
You can buy off the shelf battery systems here in Australia, about the best deal I can find costs $5500 for a 10kW pack with 200Ah cells installed.
So if I use these packs it is around $27500 for the house battery.
I love electronics and writing software and so the idea of just building the battery myself is more attractive that buying an off the shelf unit.
Looking around about the cheapest cells I can get are the Varicore 280Ah from the MEIBrand store. These are only $150AUD ($111 USD) delivered!
Looking at the photos I guessed they are really Lishen cells and that they are second life from looking at the terminals and messy laser welding.
So the Lishen was a 272Ah to start, I know they often test higher for the first few tests but they settle down eventually.
I ordered 16 cells for $2396AUD on September the 4th. This was the whole price including delivery and import duties.
My cells arrived on October 22nd.
The cells were really well packaged in large cardboard boxes and surrounded by thick custom made foam.
The cells could not have been damaged by normal transport.
I visually inspected each cell and weighed it and they were all 5.2kg +-140g
The cells are all clean and undamaged. If you lift the black cover on top you can see where the original serial has been scratched off.
The new terminals are laser welded on you can see where the old ones were ground off. The welding is B grade.
I tested the MR of each cell and they were all pretty close.
I checked the voltages and they were all close to 3.2v.
I selected the cell with the highest IR and ran a full charge to 3.65v and then a discharge to 2.5v on my EBC-A20 and the cell delivered 255Ah
I'll test them all eventually, but I was expecting this to be the worst cell due to the IR and so it was my baseline.
So these cells look to be down about 10% from new capacity, that equates to about 1500 cycles old.
I asked around and I found a guy who thinks that if you are lucky many of these cells came out of large UPS that may have spent most of the time fully charged.
He said if you were unlucky they may have come out of a bus and been worked very hard.
From the science i can find, lifepo4 batteries that have been cycled very lightly or kept mostly full can recover 10% when they are put through several full charge/discharge cycles and so those UPS batteries have the potential to actually improve initially!
Anyway, so it works out like this:
MEI Varicore 280Ah re-lifed Lishen 272Ah
Tests as 255Ah
Cost delivered of $150AUD per unit
Cost 59 Cents per Ah
Cost 18 Cents per Wh
So if I build my battery from these cells I get a 13kWh battery for $2400 (cells) plus $500 for the BMS/Cables and box.
So that means a 50kWh battery will cost me $11600 to build myself.
I've been buying from China for decades and I've dealt with many different factories and intermediates.
When you import something yourself you take a risk, I have seen guys in a freight company playing football with packages. I have seen guys in distribution centers open boxes and replace items with bricks or counterfeit items.
There is always the chance that you might not get what you expected. I always consider that I am self insuring myself with the lower price.
When I can I take out insurance on any shipment, but I always pay with either PayPal or a Credit card so that if I get ripped off I can (probably) get (most) of my money back.
I'm not suggesting this is the way anyone should go, you can buy quality brand new cells from Amy for about 39% more, and you won't have to worry about testing and balancing them or adding a BMS etc.
In my solar system the cells will likely never see more than 50amp discharge rates as I'll have 4 48v packs in parallel (each with it's own BMS) and the charge rates will be much lower. I'm going to limit the usage to the 80% of capacity which gives me the 40kWh that I think should be more than enough.
By doing this I would expect these cells to last a really long time.
I'm still planning to buy most of my cells new from Amy, but I think I'm quite happy with this purchase.
I know someone is going to say "But dude you bought 280Ah and you got 250Ah so you got ripped off" but personally I find it hard to feel ripped off when I got 13kWh of batteries for $2400 ;-).
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