Adding Extra Battery Power to FFE

[skyguy_6153]

The Focus Electric (2012-2016 model years) uses LGX P1 cells, and more info on these cells can probably be found from the endless sphere forum page. I I'd like to make a pack out of cylindrical cells, as that would rid the issue of cell expansion that FFEs have. I wonder if you found some cells that were higher in energy density, but had the same full discharge/ full charge ratings as the OEM battery, could you still utilize the OEM BMS? Or would the boards built into the modules need to be removed and reused on the diy battery....

[Anti_Climax]

You'd probably need the boards or you'd have to be able to recreate the data stream the BMS expects to see.

[triangles]

You'd probably need the boards or you'd have to be able to recreate the data stream the BMS expects to see.

And that is my big stumbling block.

Someday if ever feasible, I will upgrade my battery. The battery part and BMS part is no problem. However I'm a complete noob when it comes to canbus or knowing what the car expects from the battery modules.

It would be awesome if there was an easy way to just ditch the OEM battery and build a custom battery that just "plugs into" the FFE.

[skyguy_6153]

You'd probably need the boards or you'd have to be able to recreate the data stream the BMS expects to see.

And that is my big stumbling block.

Someday if ever feasible, I will upgrade my battery. The battery part and BMS part is no problem. However I'm a complete noob when it comes to canbus or knowing what the car expects from the battery modules.

It would be awesome if there was an easy way to just ditch the OEM battery and build a custom battery that just "plugs into" the FFE.

Look into Arduino products and shields for an easy learning route to sniffing the CAN. I started with my FFE using a Arduino Uno and a Sparkfun Can Bus Shield, but as soon as I ran the code, the car threw just about every warning it could generate (SSN, ABS, Low Tire Pressure, etc.). Luckily, I have Forscan to clear the errors, which were Can Bus related. Anyway, I think it may be due to not having the fuses for the traction control/ABS and pedestrian speaker installed . I will however be trying again in me free time with fuses installed.

SparkFun CanBus Shield: https://www.sparkfun.com/products/13262

SparkFun LCD: https://www.sparkfun.com/products/9395

Arduino Uno: https://www.sparkfun.com/products/11021

OBD2 to DB9 Cable (Needed for connecting the board to the OBD2 port.): https://www.sparkfun.com/products/10087
2012 Focus Electric with DIY P0A0A fix "coolant leak inside battery" (removed coolant hoses, heat exchangers, and cooling assembly from uppe

[Anti_Climax]

Connecting your CAN+ and CAN- backwards will do that too, as will having a termination resistor on the loop when another is already in elsewhere.

[Trinhray]

How do you get Forscan to clear P0A0A? Dealer cleared it with no problem.

Repeatable. I was able to trigger the SSN warning twice with P0A0A. Just by pulling the orange interlock fuse behind the rear seats on the upper battery pack. My FFE was towed two times to the dealer just to clear this code. No other fix performed.

[Trinhray]

With the cost of raw Li-ion cells going down, I am considering add external batteries (86 series) suggested in the forum but concern about triggering codes I cannot reset with Forscan. When putting the pack back together, were there any codes triggered and how did you clear them?

[skyguy_6153]

With the cost of raw Li-ion cells going down, I am considering add external batteries (86 series) suggested in the forum but concern about triggering codes I cannot reset with Forscan. When putting the pack back together, were there any codes triggered and how did you clear them?

When I rebuilt the battery in my first FFE, I was unable to drive the car because I forgot a busbar between two modules . Once I bolted that in, I ran a self test on the BECM through Forscan, and checked/cleared any DTCs. You have to go to the DTC (left side of window in Forscan) tab to clear any DTCs in Forscan. When in the tab, there are two yellow triangles at the bottom (one for reading DTCs, and one for clearing and reading.).

[ivankovff]

Hello, please can you read BECM module with FORScan, I reqyire the file of configuration for the battery of 33.5 kWh to compare it with the battery of 23 kWh. Thank you in advance for your precious help

[Trinhray]

Thanks Skyguy_6153. Can you just attach additional batteries of the same voltage range to the rear junction / disconnect next to the rear interlock fuse on the upper battery? Why did you connect the negative to the front of vehicle? If I can clear codes, I might proceed to building my own 86s pack with raw cells and custom bms.

Clearing DTC codes:
I tried using Forscan (two months trial + ELM327 HS/MS adapter) to clear P0A0A:08 but could not. Since I know the dealer can clear it twice. Everytime I open any of the HVIL connections, it will trigger a code and in the case of the interlock fuse, it is SSN warning.

Maybe it's the cheap ELM adapter or limitations to trial version. I just purchased the extended version of Forscan and their recommended OBDLink EX FORScan OBD Adapter. Let's see if it makes a difference.

Thank Skyguy_6153 for confirming that Forscan can clear the codes when everything is reconnected back properly.