EV batteries for powerwall

Hello, new here and been lurking and doing a lot of searching but haven't found what I'm looking for. I just moved from 24v to 48vsetup, off grid. Midnite classic 150 w/whizbang, Aims 6kw split phase inverter with generator backup. I also have a Victron smart Battery protect (Bluetooth one that is programmable as a safety next for low battery cut off). currently 4@265 solar panels top of pole. I'll be adding more panels to a new top of pole, either6 or8 @ 300+ watt and the old ones will go onto another controller to the same battery bank most likely.

This runs our shop and soon to be completed tiny home (358 sq ft).

the big question is regarding the battery storage, I currently have Nissan leaf configured in a 7s2p for about 2.5 kwh of storage. I'm not a big fan of the leaf batteries, mostly cost and time to build with a lot of exposed terminals, they are in an insulated box during winter months but I take the top and side off for summer thus I had to come up with ways to make sure nothing hits the bus bars on the terminals etc.

My question is, has anyone used the LG Chem packs (16 cells 3kwh each, 64volts) as a power wall or other type of "pack" configurable system? Chevy Spark or ford cmax? I'm looking for scalability and quicker way to add capacity as needed. I would like to be up to about 24-30 kwh of storage by spring.

I'm familiar with the volt builds but right now the LG, Spark and Cmax seem to be the better cost route and more availability.

Thoughts?

My inverter and chg. controller have a good range to work in. Here are the specs of each
Aims:

• Minimum start voltage: 44 VDC
  
• Low battery alarm: 42 Vdc-44 VDC
  
• Low battery trip: 40 VDC-42VDC
  
• High voltage alarm: 64 VDC
  
• Low battery voltage restart: 53.2 VDC

Classic - 12-72v

Thanks!

I'm going with 25Ah Ford cells from Cmax Energi and Fusion Energi cars. They come in 7.6kWh packs with four 21s1p sections that can break down to individual cells, and I got a few at about $150/kWh. Their connectors are on top but mostly covered with plastic that's part of the busbar; to enclose it 100% there's screw holes you could secure a sheet of plastic with.

Mazlem said:

I'm going with 25Ah Ford cells from Cmax Energi and Fusion Energi cars. They come in 7.6kWh packs with four 21s1p sections that can break down to individual cells, and I got a few at about $150/kWh. Their connectors are on top but mostly covered with plastic that's part of the busbar; to enclose it 100% there's screw holes you could secure a sheet of plastic with.

Click to expand...

Thanks Mazlem, I really like the look andlayout of these cells and I like they are not pouched cells. I take it you found a full pack from a savaged car? I see them in lots of X cells but not in the 7.6kwh packs on ebay.

Yea I got three full packs from parts cars. Try searching for 'Ford Energi battery' on ebay. Half the time they don't show pics of the battery, but you can ask, or if it's definitely from an Energi model, it'll be the 7.6kWh pack. You can see the difference between the two packs here:




They're prismatic cells but do still need a bit of compression.

Mazlem said:

Yea I got three full packs from parts cars. Try searching for 'Ford Energi battery' on ebay. Half the time they don't show pics of the battery, but you can ask, or if it's definitely from an Energi model, it'll be the 7.6kWh pack. You can see the difference between the two packs here:




They're prismatic cells but do still need a bit of compression.

Click to expand...

Thanks! last question, did you do 14s or 15s and are you using a BMS?

Since each section has 21 cells, I'm setting them up as 7s3p. The cabinet they're going it can hold two sections per shelf, so I'll be putting two in series for 14s per shelf, then paralleling each shelf. Pretty sure I'll be going with Batrium to manage it. Should've started my own thread a couple months ago.

Mazlem said:

Since each section has 21 cells, I'm setting them up as 7s3p. The cabinet they're going it can hold two sections per shelf, so I'll be putting two in series for 14s per shelf, then paralleling each shelf. Pretty sure I'll be going with Batrium to manage it. Should've started my own thread a couple months ago.

Click to expand...

Searching on Ebay and comparing to your pictures I had one more question, is the picture showing the difference between the Hybrid models to the Energi models? Or is that the difference in pack size between the Cmax and Fusion?

Thanks!

I am using Samsung / Bosch modules out of a Fiat 500e. An opportunity came up to acquire these so I jumped on it even though I was looking for something else at the time.

The modules are 5s each, making 15s total with 3 modules in series. This fits my choice of inverters quite well.
63 VDC MAX @ 4.2v per cell
45 VDC MIN @ 3.0 per cell
I will likely be cycling between 4.0 and 3.5v per cell.

If you can get a pack from an entire vehicle there are a mix of 5s and 6s modules, so you could also build up a 16s configuration too.

So far so good...each module is testing near its rated capacity of about 1.1kWh each.

rherman said:

Searching on Ebay and comparing to your pictures I had one more question, is the picture showing the difference between the Hybrid models to the Energi models? Or is that the difference in pack size between the Cmax and Fusion?

Thanks!

Click to expand...

Yea the smaller pack is from standard models and has 5.5Ah cells for a 1.4kWh total. The bigger pack is from the Energi models with 25Ah cells for a 7.6kWh total.

Im using two of the 60v Chevy packs and its working great.. 6kw