Heavy Traffic Draining Hybrid Battery

YES the battery guage your looking at when it shows one bar left the battery has around 40% charge left. Don't worry and just drive. the car will not let the battery go below the 40%.

 

Yes, the car manages the battery state of charge (SoC). It likes to keep the battery at 6 bars.

Low bars is not really low on the battery, it's just low on the range of charge. However, even within the safety margin the Prius uses, it's still worse for battery life if the car is doing a lot of deeper discharge cycles.

At the end of my commute home I had the battery dropping constantly dropping to 2 or 3 bars because close to the end I have a couple of stretches of slight uphill at 25 and then 30 miles per hour and if I simply maintain constant speed the car would be under heavy EV use. To avoid that I use P&G, with the pulse under gas. If there are cars behind me I maintain speed by using frequent pulses. I now arrive home with the SoC at 4 to 6 bars.

 

LOL PriusSport, that sounds more like a question that a newbie with one or two posts would write, rather than someone with over 1300 posts!

When you're driving very slowly then yes it does try to keep the engine off as much as possible. But once it gets down to about two bars then it will always start the engine so there's no problem.

 

"Those are exactly the type of traffic conditions where plug-in's and full electric's are going to be an awesome advantage."

Actually, I think this sort of situation is going to be the Achilles heel of electric cars. What do you think will happen when an electric car driver is stuck in traffic with an already drained battery, the lights are on, the AC needs to be running and maybe the wipers as well? That battery is going to drain fast as well! So you can turn off the AC and swelter, but who is going to be happy about that?

I am no expert on electric cars, but I know the range is very limited and finding oneself in a huge traffic jam is with only a partial charge is going to be a challenge. Think about the electrically run devices you have used that suddenly lose their power, and usually this event is unpredictable.

 

I live in a different climate, and have no concept of needing AC for cooling simultaneously with lights or wipers. Needing AC for defogging, yes, but that is temporary.

An hour of headlights should reduce EV range by less than a mile. Wipers shouldn't be any worse. The low speed of the traffic jam should make up for both. So the AC problem should stand by itself, not aggravated by the other fixed loads.

A driver in trouble for encountering a traffic jam with an already drained battery was likely in trouble even without the traffic jam.

 

same as a gas car with no gas.

 

Hi Folks,

First time posting here. I have a 2008 Prius and Id been loving my car till last Sunday This happened when I was driving in SFO city on the Lombard street (uphill). It was bumper to bumper traffic and the car was going just fine, and at one point it just stopped and wont pull up. I had half+ tank of gas, battery was showing 4 bars, the car was ON (all electrics okay) but wont pull up even when pressing hard on the gas. There was a triangle warning light that came (system malfunction or something). I even restarted the whole thing, but no help.

Finally AAA came and towed the car and brought it back to the normal road and it started running fine??

Anyone knows what could have happened? My car service (dealer) says the battery (not the hybrid one) could be dead/low.

Thanks
V

 

It sounds like the hybrid system went into safe mode aka limp mode. Did you also notice that the A/C stopped working? If so, that would pretty much confirm that the inverter is/was overheating due to a faulty inverter pump. Toyota issued a recall on the pumps earlier this year. Your car may be subject to that recall. I would check to make sure the inverter pump is working properly.

Watch the following video, then check for the turbulence as demonstrated in the video. If NO turbulence, the pump is NOT working properly. The inverter pump should run ALL of the time when the Prius is in "Ready" mode.

You can also check the voltage of the auxiliary battery with the MFD. There is a link to this procedure in my signature below. (Test the battery). It is a well known fact that a failing 12 volt battery can make the Prius do some strange things, but it is also possible that you have more than one problem.

If you have access to a Toyota compliant scanner you should check for codes utilizing the OBD port since you mentioned the red triangle warning light. If you get a P0A93 code on the scanner, the inverter pump will more than likely be the problem.

Luscious Garage | Blog | Prius Code P0A93: Inverter Water Pump Failure

 

Exactly how to do it. Learn Warp Stealth, no arrows at all, just free rolling! Plan on it on downward slopes, feather uphill battery, regen when ever you can. Some of my best results have been on the Cal "5" heading to San Diego in really bad traffic. Upper 50's!
For me that's killer!

 

Thanks a lot. I will check on the Inverter pump. I turned off the A/C when I was starting on the uphill, so didnt know the A/C stopping thing.

 

Just FYI, a Red Triangle warning on a steep hill with no stored diagnostic code means low oil. Could have been so much drag inside the engine due to lack of lubrication that it wasn't developing any power. Check your oil. I know it sounds crazy.

 

I should have mentioned that too, thanks for bringing that point up.

 

Don't forget to let us know your checks, repairs, and outcome for the benefit of the knowledge archive.

 

I'm exhuming this thread because it matches a complaint I've had with the Gen 2 Prius ever since the first traffic jam I've had the misfortune of getting into with it.

I will never buy another Prius because Toyota's engineers didn't make it possible for the driver to keep the ICE running when inching along during a traffic jam.

I was in another bad one yesterday. It took over 30 minutes to drive 4 miles. The ICE was already warmed up when I got onto the Interstate and after a mile I ran into a huge back up. The next exit was 5 miles ahead - go figure.

Naturally, the battery charge level dropped to the point when the ICE had to turn on to charge the HV pack but you never get enough time to charge it because as soon as you're moving you come to a stop again and the ICE shuts off again. So I did my best to keep the pack charged by revving the engine so it wouldn't shut off as best as I could which worked but was really annoying for my passengers who were getting whiplash from it.

It would have been relatively easy for Toyota to include an ICE always on mode for situations like this. Just long enough to charge the pack to five or six bars would have done it.

 

Jazz,

You are overly concerned with the State-Of-Charge (SOC) of your HV battery. Your Prius manages the SOC just fine in traffic. The ICE only runs a short time when the SOC gets below 40% or when the CAT cools down below a threshold. When you get out of traffic, the SOC will get back up to 60-70% (5 or 6 bars) pretty quickly.

JeffD

 

The Prius was designed as an Super Ultra Low Emissions Vehicle (SULEV). It is doing exactly what it was designed to do. Minimise emissions in traffic jams, even after the HV Battery SoC drops.

Don't worry about the HV Battery running low. This is neither a plugin, nor a full electric vehicle.

Leave the energy levels of the HV Battery to the vehicles ECU. It does a brilliant job of protecting the battery while saving you fuel.

Also take heart in the fact that other vehicles in that 30 minute 4 mile traffic jam must have expended far more energy and fuel overall, compared to the frugal Prius.

I've occasionally been in similar snarl ups, but I've come to appreciate how the Prius handles them, even after the charge in the Traction Battery drops to purple. The battery will never be allowed to run out. There's always enough to smoothly start the ICE, compared to other cars with Stop Start Technology whose 12 volt batteries would have a hard time repeatedly starting engines in those conditions, over that length of time.

Very impressive technology indeed - so much so, it's easy to believe conspiracy theories suggesting it was originally designed by extraterrestrials....


iPhone ?

 

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Thanks! I didn't know that-
I thought the peripherals ran solely on the 12v.

 

They do run from the 12V. But that, in turn, is kept charged from the hybrid battery through an inverter.