I second ShadyEscape's suggestion. I realize I'm talking mostly out of thin air here but I notice on my 2010 that when you start the car and it sits in EV mode, everything powers up, the car is "READY TO DRIVE." OK, sit there for 30 seconds and then turn the key off. When you switch to OFF, you can hear several audible relay clicks emanating from the **passenger side dashboard area**. They're loud enough to be heard and therefore I'm guessing the circuits they switch are pretty powerful. I am wondering if you've maybe got a sticking relay that is not powering "off" and somehow has a circuitous connection to the HV battery via the DC/DC converter? If there is some circuit that is sticking "power on" and draining current.....that somehow winds up draining the HV battery...

It would be odd for a relay to stick "ON" but anything is possible after 11,12,13,14 years.

 

The only failure that could contribute in this fashion is the main relay in the battery. This relay isolates the HV battery from any system that might draw power from it. Additionally, a secondary failure would have to occur to continue to allow systems to function with ignition off.

These batteries have the same Sanyo cells as the 06-11 HCH. The primary failure mode of these cells is excessive self-discharge.

 

Thanks SKeith and everyone else. Now for the weirdness! Apparently when it rains it pours on the longstanding members of the Ford Escape Hybrid Forum.

Last night something very anomalous happened with my '10. I parked the car around 6:30 p.m., went inside to finish up some chores and late work, and around 9 PM I was pooped and decided to drive into town and pick up some pizza for dinner.

When I started the car, the Info. Energy Flow screen was on, and there was ONE LOZENGE displayed for the HV battery. Almost empty. The ICE engine started right away into "IDLE WITH CHARGING" and I was, for lack of a better word, a bit freaked out. At 6:30, I had parked the car with the battery in the middle of the range, where it usually is. In 2.5 hours it had somehow discharged to just ONE lozenge on the display. I drove the car into town, taking the hills in "L" to maximize regen., and it climbed back up to the midpoint and a little higher. Got home, everything's working fine. Made sure to turn off all climate control and all accessories. Parked the car.

I was very concerned that the HV system was leaking somehow, so I ate dinner, set my alarm for 2:30 in the morning, and went to bed. At 2:30 am it was right where I left it. At 7:30 am it was right where I left it. No repeat of the behavior.

I've never seen the battery that low on the display, and it was a complete surprise to me. So far, that has not repeated itself.

Now I'm worried that I have an intermittent drain somewhere that will leave me stranded. Again, this has never happened before and the battery appears to be holding its charge again. My 12V battery is only a few months old, and I have ZERO warning lights.

 

Your 2010 does not have a rear evap for the battery and relies on cabin air for cooling. Your battery is subjected to much higher temperatures and wider temperature ranges. As I mentioned before, this influences SoC. It gets worse as the battery ages and degrades.

You are likely just seeing the initial symptoms of battery failure.

Can you monitor the temperature of your battery?

If you can run the forscan balance first thing in the morning with the A/C blasting and the battery temperature under 90°F, it's probably worth seeing if that improves it.

 

I am waiting for my new laptop to arrive, which should be Friday. My old machine with FORScan on it died when it last tried to update Windows 10 on "Patch Tuesday." It was an ---old--- laptop that had originally been running Windows Vista and we press-ganged it into service for Windows 10, which it did not like at all. On Friday I should receive my new one, on Saturday I'm going to run the battery balance function and report back on the results and behavior over the next few days especially if I see it again.

BTW I am now using a sunshade for the windshield, from Heatshield, Inc. in CA and it really works to cut the cabin temperature down by about 20-25 degrees in direct sun. The dashboard is MUCH cooler to the touch.

If you visit the Heatshield website and enter 2010 Ford Escape the "outline" photo shows the wrong car but the exterior and interior pictures are a Mazda Tribute from the correct year. Despite that discrepancy, their shield is #310 for the Escapes from these years, and it *FITS* perfectly. In fact it fits so well that you do not have the use the interior sunvisors to hold it in place, which is great because I don't want to turn my visors 180 degrees hundreds of times. You basically work it into the crevices of the windshield, I'm very pleased with it for $44.95 plus shipping. It's a well-made product (made in USA). Their shipping price was the same as Amazon's so I ordered it direct from them.

Thanks again.

 

Also: This morning I took the car for about a 30 mile trip and when I parked it, there were 7 of 10 (?) lozenges showing on the HV battery, slightly "overcharged" from where it usually is. I parked at 11:00 am and just went out at 3:00 pm and it is exactly where it was. I'll report back all my findings and if this 2.5 hour apparent rapid discharge occurs again.

 

Alex, it might be worthwhile to record HV battery voltage along with the SoC. I'm now seeing that when my SoC drops to 30% the battery voltage remains at about 337v, I would have expected voltage to fall somewhat proportionately to SoC since SoC is a derived value, I think. I set my Scangauge to display SoC and TBV side by side.

My low SoC "events" occurred over time and got progressively more frequent:

• 2016 - 1x
• 2017 - 1x
• 2018 - 3x
• 2019 - 7x
• 2020 - 12x
• 2021 - too numerous to record
• 5/25/21 - HV battery was replaced but low SoC events continue at a weekly or higher rate.

 

Steve,
What I understand from your post is that my low SoC events (20% drop) are almost certainly internal to the battery. But that would mean my "new" Greentec battery is having exactly the same self-discharge failure as my old original battery. That just seems highly unlikely but Greentec does warranty against that exact problem.

I should do the following to confirm battery self-discharge and not external load is the culprit:

• Garage the car at a nominal 52% SoC
• Open HV Service Switch and remove driver side battery connector
• Record SoC and HV battery voltage from Scangauge
• Every 12 (or 24) hours record SoC and HV battery voltage
• Continue until a low SoC event occurs or 3+ days have elapsed

I can't try this until later in July when I have a window of time not needing the car everyday.
What do you think?

 

Why is it unlikely? It's likely they sold you a salvage yard battery that's > 10 years old with only minimal testing. You have a history of progressively worse self-discharge with an ailing battery.

Furthermore, that's how these Sanyo cells fail when subjected to higher temps. Pre-2010, cells were rarely allowed to exceed 90°F, and the car basically disabled the hybrid system if temps rose above 100°F. Now your battery likely routinely operates in excess of 110°F.

The seemingly random nature of the SoC drops indicates temperature is a factor.

The mechanism for something to draw anything from the hybrid battery only exists at the data plug on the driver's side, and it's unlikely that anything is pulling anything from the HV battery when the ignition is off EXCEPT for the voltage sensing wires.

Here's a revised procedure:

• Garage the car at a nominal 52% SoC
• Allow it to sit for 2 hours to allow battery voltage to settle and temperature to stabilize.
• Remove safety plug - this is removed first to ensure the HV battery is not subjected to a load when you engage the ignition.
• Record SoC, HV battery voltage, battery temp and the module voltage difference from Scangauge.
• Remove driver side battery connector, and remove main harness connector - make completely certain the battery is completely isolated from the car.
• Allow 3 days to pass
• Reconnect main harness and data cable (no safety plug).
• Record SoC, HV battery voltage, battery temp and the module voltage difference from Scangauge
• Install the safety plug.

See if you get a big voltage and/or SoC drop.

 

It seemed unlikely to me that a different battery would be in exactly the same state of decay as my original battery, that's all. The new battery has corrected all the problems with the original battery except for this self-discharge phenomenon which is unchanged.

My FEH is a 2007 so I don't think high battery temperature is an issue here. I monitor BTM and have never seen it exceed 87°F in operation.

Thanks for the detailed test procedure, I will do exactly that.

It's also puzzling that SoC decayed from 50% to 30% with voltage only changing from 337v to 335v. I would think SoC is calculated from a stored constant generated during a recalibration event.