Temperature Exteremes - Battery Charge

[Old-Crows]

The temperatures have been above 90F for several weeks now. I've noticed that the ICE runs a hell of a lot and the MPG has gone down the drain... Between 30 and 35 in the TCH. The battery state of charge level indicator seems to be nearly down at the bottom every time you crank up and it takes a fair bit of driving to get it charged up to a high level. Consequently, the ICE runs a lot.

I know temp extremes affect the state of charge of a battery. Could these high ambient temps be sucking the charge out of the traction battery??

(Running with the "ECO" on or off makes no difference.... except that the car cools better and faster with it in the "Oh-EFF-EFF" position.

Any thoughts Gents???

[LCromwell]

Originally Posted by Old-Crows

The temperatures have been above 90F for several weeks now. I've noticed that the ICE runs a hell of a lot and the MPG has gone down the drain... Between 30 and 35 in the TCH. The battery state of charge level indicator seems to be nearly down at the bottom every time you crank up and it takes a fair bit of driving to get it charged up to a high level. Consequently, the ICE runs a lot.

I know temp extremes affect the state of charge of a battery. Could these high ambient temps be sucking the charge out of the traction battery??

(Running with the "ECO" on or off makes no difference.... except that the car cools better and faster with it in the "Oh-EFF-EFF" position.

Any thoughts Gents???

I will ask my wife what hers is doing and report back to you today.

[LCromwell]

Originally Posted by LCromwell

I will ask my wife what hers is doing and report back to you today.

Wife's is fine, the only thing she noticed with the HOT weather is the after turn off noise is longer. I assume that is the electric engine fan running to cool the motor down. So maybe it is time for the dealer to look at the charging system for the drive battery or maybe the drive batteries are going out, as it sounds like it is not holding a charge. You are using the gear shift in "B" when ever you slow down or brake right?

[CarLuvrSD]

I have the same problem in the summer. My car is magnetic gray, so get hot and stays hot. The problem is, the interior of the car gets too hot for the batteries to work safely, so they shut down.

The usual ways of cooling your interior will help. Use windshield sun shades, park in shade whenever possible. Crack windows 1/2 inch or so. Once your interior cools enough, the battery charge will start to climb.

Also: Cool down the car with A/C on high, then switch to ECO. Remember, the intake for the batteries is in the rear package tray, so direct your center A/C vents over your head, to reach back there.

I know these steps work, because my wife never uses them, and her summertime mileage can be as low as 26 on the same trip I get upper 30s.

Durring spring and summer, when outside temps are mild, I average 38mpg. Long trips, even in hot weather I can achieve low 40s. During extreme cold or hot weather, I usually average 33 or so per tank. (mostly city) I live on a mountain, in extreme cold weather, the engine runs all the way down the hill to the freeway, about 5 miles, then runs all the way back home on the way up the hill - doesn't help. When I arrive home, my batteries are usually near full charge. I wish I could switch to electric only mode, so I arrived home with drained batteries.

[Old-Crows]

Originally Posted by LCromwell

Wife's is fine, the only thing she noticed with the HOT weather is the after turn off noise is longer. I assume that is the electric engine fan running to cool the motor down. So maybe it is time for the dealer to look at the charging system for the drive battery or maybe the drive batteries are going out, as it sounds like it is not holding a charge. You are using the gear shift in "B" when ever you slow down or brake right?

Thanks LC!! Yes it does that... runs pumps, etc., longer on hot days. I don't recall ever using the "B" gear. I generally brake lightly and intermittently. On --- off ---- on ---- as I gradually come down from speed. Old habit I guess... I like to get on the brakes from highway speeds and the let them cool off a bit rather than keeping them on till I come down to a stop if I can help it.

[Old-Crows]

Originally Posted by CarLuvrSD

I have the same problem in the summer. My car is magnetic gray, so get hot and stays hot. The problem is, the interior of the car gets too hot for the batteries to work safely, so they shut down.

The usual ways of cooling your interior will help. Use windshield sun shades, park in shade whenever possible. Crack windows 1/2 inch or so. Once your interior cools enough, the battery charge will start to climb.

Also: Cool down the car with A/C on high, then switch to ECO. Remember, the intake for the batteries is in the rear package tray, so direct your center A/C vents over your head, to reach back there.

I know these steps work, because my wife never uses them, and her summertime mileage can be as low as 26 on the same trip I get upper 30s.

Durring spring and summer, when outside temps are mild, I average 38mpg. Long trips, even in hot weather I can achieve low 40s. During extreme cold or hot weather, I usually average 33 or so per tank. (mostly city) I live on a mountain, in extreme cold weather, the engine runs all the way down the hill to the freeway, about 5 miles, then runs all the way back home on the way up the hill - doesn't help. When I arrive home, my batteries are usually near full charge. I wish I could switch to electric only mode, so I arrived home with drained batteries.

Thanks! I think you are on to something.... That's probably what's going on!! Our Cammy is also the 'magnetic gray' with a light gray interior. We generally keep the window shade in the windshield and open door windows (we have vent shades). Sometimes I pop the moon roof. You are right on the mark... the traction battery doesn't start to charge until the interior is somewhat cooler according to the MFD. This might be a reason to open the rear seat A/C vents and help cool off the back seat area a little quicker.

Also, since it is sooooo hot here in Hill Country right now, the HVAC automatically goes to RECIRC. That prevents air from flowing down that battery ventilator I'd think. Maybe the old saw about opening all the windows for a couple minutes isn't a bad idea either. I don't do that, sorry to say. I just crank'er up and drive on.

One more idea.... the traction batteries bake from the bottom as well as the top. Street temps are way up there and that radiates up to the bottom of the car toasting everything very nicely ... top and bottom, thank you very much!!! Even in the garage it can be 90 some on a hot day. I'll bet those puppies get pretty warm on a 100F day. So paying attention to their cooling should be helpful.

Say, maybe we could rig up some sort of chiller using a bag of ice from the Quick Shop.... just stuff the chips down the battery vent.... that'll do it!!
Our mileage is about the same ... 32/33 right now. Upper 30s/low 40s in temperate weather.

[LCromwell]

Originally Posted by Old-Crows

Thanks LC!! Yes it does that... runs pumps, etc., longer on hot days. I don't recall ever using the "B" gear. I generally brake lightly and intermittently. On --- off ---- on ---- as I gradually come down from speed. Old habit I guess... I like to get on the brakes from highway speeds and the let them cool off a bit rather than keeping them on till I come down to a stop if I can help it.

Do yourself a favor and read about using the "B" in the gear shift. It was put there for a specific reason, to keep the driving battery up to full charge. You should be pulling it into "B" anytime you are slowing down or braking until you come to a complete stop or resume an accelerating movement. Use the Disp on your steering wheel to get the battery pic to show and you will see it going down and back up as you use the "B" shift. It takes getting use to, and remembering to up shift once you start going again. If you forget to up shift I have not noticed anything, but then I have never not up shifted for more than 60 sec before I remembered to look at the shift indicator in the dash to be sure I have up shifted. When you are at idle, never put it in Neutral, always keep it in drive.

[CarLuvrSD]

When deciding whether I'll use the "B" mode in my transmission I consider whether or not my engine is already running or not. I've learned that light braking, with no sudden pressure on the brake pedal charges the batteries quickly. When the engine is ice cold during winter, I use B mode on long hills, instead. I drop 1k feet in altitude between my house and the freeway, which is just shy of 5 miles. Using B mode helps the engine warm up about 1 mile sooner. But I frequently arrive at the on ramp with an 80% charge. Descending the hill using maximum regenerative braking, usually get me to the on ramp with 100% of the bars lit up.

Believe me, it's a lot more fun merging in the morning when my batteries are full. I love whisking past all the modified Turbo Diesel pickups and punk kids in their riced out, torque-less wonders. I had one kid try to race me at nearly every stop light, all the way into Salt Lake city a few weeks ago. I did beat every-time I could, as in nobody before me, or cops nearby. He was in an Acura integra, The only time he got in front of me was on I-15, but he had to go 90 to do it. I won't exceed 80. I generally lay off people who really are trying to race me, but the look on this kids face was priceless. Major cognitive dissonance.

Anyways, I have another bit of wisdom to share. I just learned this this year, after owning my car for almost 2 years. Since my car doesn't have the extra readouts you get in a Prius or with Nav, I've learned to play it by ear - and feel. MY goal is to get wherever I'm going without ever using my regular brakes. I can feel them kick in. Regenerative braking can be judged by the whirring sound of the generator. The new bit of information, I read on a forum, is, that the regenerative braking is most efficient during the last part of your braking. You can hear it, just before you come to a complete stop, and it's common for the battery indicator to climb a notch just as you're coming to a complete stop.

I don't use my real brakes much. According to my dealer, at my last service they estimated my brake pads would last till I have 110k miles on my car!