hybrid battery is low overnight (maybe heat related?)

you're gonna want to wait for Seilerts on this one but I want you to prepare yourself for some bad news.

I truly hope Seilerts says nothing major is wrong. But while we're waiting for Seilerts to see this thread, why don't you give him some more information:
when was the 12V battery replaced and was it DENSO or Optima?
how long does the car sit at work and what time do you get out of work?
what is the air temp when you leave work and how short is your drive home?
what is the air temp in the morning and what time do you leave for work?

and the most important piece of information we need is Does the gas engine (ICE) turn off at a stop light after it has been given enough time to warm up?

I didn't ask if any warning lights were on cause I am under the assumption that if they were you would have mentioned it in your original post, so just confirm that there are no triangles of death or christmas lights on your dash.

 

Well considering you run the AC full, no wonder your battery is run down. I can sit in the line at In and Out for 10 minutes and it sucks my battery to purple! Turn the AC off, you will be amazed how much gas you will save.
Also with only a one mile commute, I don't see why you just don't walk! The car will waste gas warming itself up only to be driven a mile and parked. Not much time there for a charge! What do you get for MPG anyway??

 

With having a garage and with such a short commute and your need to run the a/c on max I highly recommend figuring out a way to permanently install a trickle charger on your 12V battery, especially since it is a DENSO and not an Optima. I think the 12V runs your a/c, then your HV battery drains to charge the 12V, hence the drained HV battery. The trickle charger will greatly extend the life of both your expensive HV and cheap 12V batteries. In addition you will see a large improvement in fuel economy, which I'm guess you are in the low 40s or possibly high 30's.

 

no you misunderstood me i am recommending you install the trickle charger on the 12V battery which runs accessories such as the a/c. I am not a battery expert like seilets but I think this would keep your HV battery with more bars and improve your mpg greatly.

touching your HV battery is suicidal WALK AWAY FROM THE LIGHT!!!

 

AC compressor runs off a 200 volt power supply from Inverter.

 

You answered your own question. Driving a Prius such short distances routinely is hard on the Hybrid/Traction battery as it will never see a full charge. And its very hard on the 12 volt battery too which is why you see recommendations to trickle charge the 12 volt battery. Both batteries will never see a full charge.


Not sure why your nevervous at 2 bars as you will see that alot anyway. It will turn on the ICE and make it run and charge the battery. I see 1 purple bar alot sitting in a drive through. 1/2 mile down the road I'm back up to 4 bars.

Outside temp is not that hard on the Hybrid battery just sitting there if you have a good tint job. If no tint that will be a hot car unless you use a good windshield cover. The cover they sell here on PC SHOP is excellent. Custom fit and mine is 4+ years old and in still excellent shape. That really helps keep cabin temp down.

I wish I was only a mile to work. I would walk it at least 3 times a week. Fast walk it. Leave your work shoes at work and wear sneakers to & from.

 

Where did anyone get the idea that the hybrid system is ever supposed to fully charge the HV battery? Under normal operation, the HV battery should not fully charge. Only special cases, such as long downhills or cold weather, cause the battery display to go up near the top.

If the OP has a low speed run coming into his driveway, he will almost always end up with a low SOC as a function of normal operation.

Tom

 

you are absolutely correct, I only recommended the trickle charger due to his short one mile commute and need to run the a/c on max. I feel this will extend the life of his Denso since he didn't buy an optima and it will also improve his FE with that higher initial surface charge on the 12V

 

The car has a built-in trickle charger: MG1. Turn on the car and let it idle until shutoff. That is sufficient to charge the HV battery for a couple of months.

If it has been a California car all its life, then it is covered under CARB warranty 10 years/150,000 miles. Don't worry about the battery if it is still under warranty.

 

Your welcome. I have a physical job too so walking to work would not be fun.
Good luck!!

 

There are only 8 bars. If either one or two bars are displaying then they are purple. If three through to six bars are showing then they're blue, and if seven or eight are showing then it's green. Normal operation is 5 or 6 bars.

I guess you must be counting the white spaces between the bars as well. Just count the colored bars (1 through to eight) otherwise you'll confuse people.

 

Dwill, it's not you or how you operate your car. I have the same problem with my 2006. Works fine as long as the weather isn't in the 80's and sunny. But leave it in the sun in hot weather and a minute or two into driving the battery bars drop and ICE is constantly on charging the battery and the car drives like poop. There are some others that have cars with this problem too. I'm trying to figure it out right now as summer is coming and it's starting to happen again.