We just bought our 2007 Esacpe Hybrid last week. Even when it's off it's alive. The book says it will make various noises at various times even when its off. It's no wonder the book says that the battery will die if not used for 30 days!

We go into the garage to retrive something in the car and when the door is opened some pump or motor runs for a few seconds. Sometimes when I'm working in the garage it makes some motor running sound all by itself with out any intervention from me. It's alive, not haunted, but alive.

Anybody out there have a explaination of whats going on with all these noises? What is the vehicle doing, what is the purpose of this noise? Just curious.

Thank you for your help.

David Lee

 

Pressurizing and depressurizing the regenerative braking system. Unlocking or opening a door when the vehicle's been sitting awhile signals the vehicle to run the pump for a few seconds to build up pressure in the hydraulic system. About 3 minutes after the ignition's been off and the vehicle's in Park, it will depressurize that same system.

I don't have my shop manuals handy, but it goes into terrific detail on what all is going on behind the scenes. Every sound has a reason, and these you describe are all standard operation for your hybrid.

If you hear a hiss or clunk from the back, by the way, those are related to the cooling ducts and air conditioner for the high voltage battery (located in the floor of the cargo area.) Again, perfectly normal.

 

Incidentally, its not all the sounds that are draining the battery. The HV battery (which is needed to start the engine) is NiMH. NiMH batterys loose charge over time if they aren't recharged, some times a couple of percent of charge per day depending on the kind.

 

I don't think you have to worry about your battery being dead after only 30 days. I went away for 8 weeks earlier this year and before I left I filled the gas tanks on both FEH and ran them enough to make sure the HV batteries were full. My wife drove the '05 until it was low on gas (right at 6 weeks) and then switched to the '05. It started right up.

Starting with a full battery, I'd be surprised if it wouldn't start after 2-3 months.

Using a 2% per day discharge rate, would that mean that, in theory, after 50 days it would be completely dead? Or does it mean that it would lose 2% of it's current charge per day?

The difference, assuming you started at 100% and at 40% your car won't start, is 16 days. 30 days at 2% of full per day or 46 days at 2% loss of the current charge. Just curious....

 

I think the 30 day estimate from Ford is rather conservative... but don't feel like trying it.

As for self discharge rates.... to be honest I'm not sure if its % of the current charge (which approaches 0 charge asymtotically) or if its % of capacity. Also... these are NiMH but not "standard" NiMH batteries, they are a somewhat different chemistry, so I'm not sure what their self-discharge rate is and I'd be guessing if I gave one. The only point I wanted to make was that its like the amount of storage time is limited by self-discharge even if the brakes etc never cycle.

You'd think it'd be more than 30 days. Sometimes a car will sit on a dealers lot for 90days or more (they don't like them to though). It'd stink for a dealer for someone to say "I'll take that red one" only to have to jump start it in front of them

 

Exactly what happened when I bought mine, except it was the green one. It was the primary showroom display piece so it probably got a lot of battery drain with no ICE action (the test drive was in a different one).

Regarding the HV battery drain, don't worry too much because the 12V can "jump" the HV enough to start the ICE. Remember, it's the HV battery that starts the ICE, not the 12V. But if the 12V drains enough (see this thread) the electrical system won't have enough juice to even startup the vehicle control system, and then you'll need a traditional 12V jump or recharge.

 

Mine was hooked up and receiving a quick charge when we showed up at the dealership to test drive her. Like the previous poster, our FEH was the showroom display model and was otherwise not being used for test drives. They had a lower end FEH that was being used for that, but since we showed up at the dealership, VIN in hand for that exact vehicle, we were allowed to test drive it (and obviously purchased it!)

I'd been trawling for weeks until we found a FEH that matched our desired options and was available locally.

 

Everytime they opened the door and let someone sit in it..... brrrrrrrrr there go the brakes. It probably contributed to it.

 

Most of the cars I have looked at in showrooms have had the battery disconnected. I'm sure the salesmen don't want to listen to horns and see flashing lights all day.

When I bought my '04 Escape it had about an inch of dust on it and the battery was completely dead. That helped me get a better deal since they couldn't exactly say they were flying off the lot....

 

I still don't understand why it needs to do that.

My Mustang has hydraulic assisted brakes; the "power steering" pump powers both the power steering and the power brakes (no vacuum used). Obviously, there is no assist to the brakes until the engine is running and the pump is turning. There doesn't seem to be any problems with that (waiting until the engine is running for brake assist).

Therefore, I don't understand why the hybrid needs to jump-the-gun and start up the brake assist simply because any door, or even the tailgate, is opened.