Ford energi powerwall

Over the summer I switched from working on an 18650 powerwall to one with EV batteries. In looking for packs that could be broken down to one or two cells I found the Ford Fusion Energi and C-Max Energi packs that came 25Ah cells, so I bought three of those and got to work tearing them down:









There's four packs inside and a few disconnects to get it down from the 310v 'I keel you!' level. On the left is the BMS which interconnects the busses in a way that those wires have to be cut or remove two busses at a time to fully get that wiring out of the way. Also buried in that area are a couple main wires to disconnect. On the right is a solid metal bar connecting the backs (the top two are connected as a pair and the bottom two are a pair). Then in the middle of each pack there's a black cover with a disconnect to split the pack in half.











Just when you thought getting to a single pack took a lot of unbolting, there's more! Each pack is 21s1p with a plastic cover that has metal plates for the bus bar that's held down by 42 nuts and includes BMS wires for each cell plus three temp sensors. No cell-level fusing.









Now that we have a single pack without a bus bar it'll come apart quickly right? Well there's a plate on each end, four metal pieces holding them together, six braces, and plastic spacers between each cell. I don't know how much compression there was when they were assembled new, but at 50-60k miles, some cells bulge slightly and have a lot of tension.






I came up with a process of putting a board underneath so the cells don't drop, removing the braces, running a strap around the whole thing, removing the top metal pieces, pushing one end of the bottom pieces out temporarily (the cells sit on them), then releasing the strap and removing one end plate.










After all that it's time to sit back and relax and take a good look at the fruits of half a days labor!

Your pile of nuts is impressive

Very cool!

Are you going to test those cells or just take a go at it?

Nice work.

I set up one 7s3p pack from each Ford battery to rotate out and test all the cells with an iCharger x8 that'll let me do regenerative discharging during the tests:




I've been charging them as needed with a couple 245W panels




To limit the tests I've done them in batches of 7, figuring if any batch is too far off from others in the pack, I'll test individual cells then.

If you use the image upload here within the forum your photos will be indexed in google & show up in the images galleries.

Those iChargers rock, the regen function is awesome!

hbpowerwall said:

If you use the image upload here within the forum your photos will be indexed in google & show up in the images galleries.

Click to expand...

Done!

I got some ends in and shortened up the wiring:




And while it was sitting there, why not do a little testing? Battery-powered fridge:




It has 6ga and 120A connectors from UPS battery packs I got from work when we de-commissioned a server room. Just need to create 9 more and wire up BMS connectors for them. Obligatory hoard box pic:

I picked up a 24U server rack to house everything including a 48v APC 2200 UPS that I got for free from work. With two charged 7s batteries, it was time for another test but first I decidedto make some hot chocolate:

Back from the dead - after idling all winter I finally got to arranging all the packs in 7s3p. Now to re-work the bus bar covers / wiring and wire up the BMS leads.

HE'S ALIVE!!!!!!!! Slacker

I did the best job I could at slacking tho!

Today was spent charging a couple packs and working on the bus bar covers / wiring. They were 21s before so a lot of the balance leads could go along with a few temp sensors (I left one sensor in the middle).




At first I figured I'd have Anderson connectors at both ends but the solid bars from the factory do make it nice an tidy.

One battery set complete! The first one always takes the longest so I'm sure the rest will just be like 20 minutes or so.

Slight problem - Those metal tabs a few pics up are the bus bars for each pack, and since the cell layout changed, I'm using twice as many tabs as what originally came in each pack, so I've only been able to finish seven.

I hadn't done this before and just measured them; they're only 1/32 thick, which gets doubled because of overlapping tabs, but with gaps it's not 100%. Dunno how many amps that can effectively handle, but if I have to buy / make more bus bars I might re-do all the packs. Anybody have a source for tinned copper bus bars? 1/8" x 5/8" would be perfect. Not sure if wider would interfere with the covers.

I found a guy selling the factory busbar pieces and picked up enough to finish the rest of my packs; got that done an all the packs charged to 52v / 3.71v per cell. Then several hours of soldering later, I had balance lead splitters wired up and balance leads installed on each pack:

I finally finished the powerwall (as much as any project is 'finished'!). At first I thought about horizontal plates to mount things to, but ended up with din rails front an back to mount the BMS' and breakers, and help secure the packs together. The smaller bus bars also got replaced with two main bars.

Now I need to figure out some solar to charge it, then later on a bigger inverter and probably one more battery pack on the top shelf, unless the new inverter goes there.

NICE!!!

Is the bottom bms balance connector seated into bms fully? Looks raised on the top. Other that that it does look good. Better than my builds have looked.
later floyd

I double-checked and it's fully seated. There's some silicone on it so that messes with the visual a bit.

Good Looks great then.
Later floyd