My wife has reported no low SoC events since we changed the 12v battery about 1.5 months ago. I'll post back if I have more information.

 

Still no low SoC events after changing the 12v battery. It's been 3 months.

 

So maybe I need to have the 12V checked out, even tho is <year old.

I'm still having random isses; but now more frequently, and it's causing driveability!

Now I can drive to work, park 8hrs with normal SOC% (45-53) and be at 20, yes 20 when time to go home! Still starts (thankfully!) but drives like a IDK, crap! NO off the line acceleration, almost reminds me of an old carb engine overchoked or something, almost has hesitation/missing sensation until RPMs are 3-4K+, no regen braking.

12V seems fine, it reads normal, getting normal charging voltages.

I did change plugs & boots recently, only has like 97K on it. AC was screwed up last summer, it was only cool at best, but wife had it so I have no idea what temp the battery pack got to.

Are there refurbs out there? Costs? DIY or does it need a dealer to do something to the software?

 

I'm also having a similar issue, but the discharge occasionally happens overnight. I have a brand new 12v Optima battery, and had it tested, so that's not the issue.

This amount of discharge isn't caused by something like a Scangauge or a light staying on. The only clue I have is that both times it occurred I had done something with the ignition key right when the ICE shutdown, like immediately turning the key to ACC position. Probably not related, but I am being more aware now of what I do on shutdown.

 

So we ended up selling our 2012 FEH. There was nothing wrong with it. We just needed a bigger vehicle and went with a 2017 Ford Explorer. Anyway, up until the point we sold a week ago we never saw any low SoC events after the 12v battery was changed.

Regarding if the dealer has to do it...I don't know. We had the dealer do it for us. I know some Ford vehicles have a "battery management system" that has to be reset. And no, I'm not talking about the HVB management system. The BMS is for managing the 12v battery. Maybe the FEH has this too...I don't know. If so maybe resetting the BMS is all that's needed.

And yes, when the low SoC event occurs HVB assist is unavailable until the charge recovery mode completes. These Atkinson cycles engines have very little torque at low RPMs which is why it feels sluggish.

 

The BMS in 2012 wasn't that complex, no RESET was needed.

 

So the low SoC overnight problem reoccurred for me yesterday. Found the SoC at 25% after sitting overnight.

SoC recovered quickly, but for my entire 120 mile trip I had no regenerative braking (maybe 80% reduced). All temperatures were normal (MET & BTM) on the SG, performance seemed normal, A/C working fine, goes into EV when it should, 53% SoC at cruise, just no regen braking, had to use brake pedal to slow on downgrades. The only other symptom was 12vdc on the Scangauge was around 13.3vdc when key ON, rather than the usual 14.1vdc.

Today everything seems back to normal, 14.1vdc on the battery, and the Optima battery tested as "good" at the shop. Regen braking seems back to normal but I will fully road test this evening on a 100 mile trip.

Any ideas what's going here and where it's headed? Tnx.

 

When i had low SOC; no regen until it was over like 40 again; but then it was back to normal again. EV, regen, etc, until it droped to 30 or less again.

So not sure why you had no regen the whole trip.

 

I forgot to mention that when going downhill in L gear, rather than regen braking charging up the battery, the ICE would spin up to 4k rpm to burn off the energy. So something is telling the system not to recharge the HVB, but BTM was setting at 77°F.

 

Thought I would post a final update on this problem as it has not resolved. In summary, the HV battery will not recharge from regenerative braking, it only recharges from the ICE. All other aspects of vehicle operation seem normal, goes into EV mode when it should, all parameters on the SG seem normal. Just no longer has regenerative braking.