Nissan Altima Hybrid Battery/Electric Motor Questions

jfc31

How long should the hybrid battery be able to power the electric motor in bumper-to-bumper traffic? My NAH is running great....has 6000 miles and I've been getting 35-36 MPG on every tank of gas. But, I've been stuck in traffic twice and both times the battery meter went down very quickly (less than 5 minutes), the EV mode stopped and the engine turned on. After 5 minutes, the EV mode went back on, but then went off again after a few minutes. Is this normal? I find it very annoying to think about burning gas when I have an electric motor available.

jojolopes

Yes, it is normal. There are variables which will affect the length of time you get out of EV only, like if the A/C is on. The computer tries to keep the battery above about 1/4 so it will turn the engine on to charge the battery up to about half when it gets low. In stop and go traffic you are taxing the battery a lot to get the car moving as opposed to if you just sat still for some minutes. I have sat in my driveway with the car on in EV mode talking on the bluetooth and the battery barely budged. So in summary, yes it is normal for it to happen in bumper to bumper traffic where you move a little then stop over and over.

langjie

yes, it's normal, the battery doesn't have that much capacity to be able to stand too much stop and go. actually, stop and go, the battery usually is ok, it's when the highway is a parking lot, that's when it completely dies. it might last about 1/4 mile when it's parking lot traffic

ibkrusty

If cruise control is off, regenerative braking works the way I would expect (i.e., braking shows as a charging of the high voltage batteries on the "Power Meter").

If cruise control is engaged, stepping on the brake pedal engages the mechanical brakes but not regenerative braking (i.e., no charging on the Power Meter). This is 100% reproducible and is true no matter what the charge level is on the high voltage batteries.

Obviously, this negatively impacts mileage unless I do not use the cruise control at all. Nissan service folks, largely being incompetent in my experience, don't appear to even grasp the issue

Has anybody else experienced this? Is this a generic NAH problem or specific only to my car?

cephraim

Sure, but when you are in CC and you hit the brakes, doesn't that take you OUT of CC mode?

langjie

actually, when you are on cruise control and go downhill (on a steep grade), the engine will help control the speed of the car and regen. I don't think their car is supposed to do that

ibkrusty

While hitting the brakes does take the car out of CC, regenerative braking is still locked out. Apparently the computer is programmed (a "bug" I would say) to lock out the regenerative braking whenever the brakes are depressed and CC is on at that instant). You can see what is happening by the following small experiment:

Set the CC for 40 mph and step on the brakes moderately. The "power meter" will NEVER dip into the blue (indicating regenerative braking) UNLESS you remove your foot entirely from the brake pedal and reapply the brakes. This time, the computer sees the CC as "off" from the first brake push, and regenerative braking works as it should.

The "Shop Foreman" at my local Nissan deal "has heard this problem many times before", but they won't do anything because it doesn't show an error code, and, therefore, "was working as designed". I asked if an error code would show if the right front wheel fell off. The service person admitted it would not. So I asked if that would mean it was "was working as designed".

tomscot2

[actually, when you are on cruise control and go downhill (on a steep grade), the engine will help control the speed of the car and regen. I don't think their car is supposed to do that]

This is excatly how it is supposed to work. What is happening is that the power from the engine is being sent to the battery instead of the drivetrain. Turn on you monitor to see this. If you go down a very long grade (1 mile or more) you should be able to move your battery capacity to the top of the range.

cheung_wilson

Hi,

I have a 2007 NAH with 40000, I thought the electric motor makes too much noise recently (around 3 months) - I'm sure the ICE was not running - when I do my "ear test".

Does anyone feel the same way about the noise from the electric motor?

Does the electric motor require any "scheduled" maintenance?

Thanks

popny85

Has anyone ever gotten their battery to be fully charged? I've driven on gas on a freeway for over an hour, expecting that this drive should be enough to fully charge a battery, but the needle never went past a little under 3/4. Is this an issue to take to the dealership? Or is this normal??? :confuse:

cheung_wilson

Yes, I think it is normal, unless you drive down hill for extended period of time, it is rare to see the battery higher than 75% charged.