Ford Focus Electric Forum

Hi,

I have second hand FFE 2012. I was expecting 23kwh battery but to my surprise when I have uncovered battery itself behind the seats the label shows 33kwh. The weird thing is that I still get around 20kWh out of this battery when car says it's empty.

Would it be possible that car is unaware of bigger battery pack?

it's possible the car wasn't reprogrammed when the 33.5kW battery was installed. I would think it would over time recalibrate itself to the larger battery but I'm no expert.

It looks like when I use around 19 kWh it leaves me with 7 km of range left. Maybe I should drive it until it stops?

Usable capacity on the 33.5kWh battery is in the upper 20's kWh. I don't know how the car calculates the battery % that shown on the screen but you might check what it says when your GOM says 7km left. If it says you have 20% left then just keep driving until the % drops to single digits. However I would suspect if the GOM is wrong the % shown on the screen could also be wrong. I think with Forscan you can read the battery voltage. If I remember correctly 3v per cell is a dead battery and 4.2 volts is fully charged. I don't remember the exact numbers so the following is approximately what the car does. The car will only charge to just over 4V/cell (90% SOC) so 86 series x 4ish volts = 350V for full pack voltage. An empty pack is 86 series x 3 volts/cell = 258 Volts. I believe the car keeps about a 5% buffer so you should never see a pack voltage this low. I don't know what this translates to in voltage but I'll guess it's probably in the neighborhood of 275 volts. Hopefully someone who has done these measurements can chime in. The pack voltage to capacity remaining isn't even close to being linear so it's really hard to gauge state of charge except when near full or near empty. The point I'm trying to get at is that you can simply use pack voltage guestimate if you are really close to empty with 7 km remaining on the GOM.

Today I've been driving until FFE stopped refusing to drive. I could get 19.1 kWh out of the battery from 100% charged. Not great for 33.5kWh battery. Wondering if the battery replacement came with separate ECU/BMS or they used the same ones.

When Ford replaces a 23kWh battery with the 33.5kWh battery there is some module reprogramming that is done. I always thought it was so the Guess-O-Meter was correct but it appears it is also to allow use of the increased capacity. Sounds like someone swapped in a higher capacity battery and didn't do the reprogramming. Might be worth the cost of having Ford update the programming.

That would be great - the only problem is that I have imported this car from Canada and I live in Europe - I'm almost 100% sure no Ford dealership here is able to do that

I would try them. Ford service is pretty global now they may have the capability to reprogram your Canadian car at your local Ford dealer. At worse they can only say "no".

I don't know how it is on your side of the pond but here in the US a ford dealer has to be electric certified to service EVs and plug in hybrids. Maybe you'll get luck and find an EV certified dealer over there.