always losing two battery bars

Depends on how hard you drive it when the engine/cat converter is cold.

When the engine/cat converter is cold, all power comes from the battery. The engine is busy idling up to operating temp. During this time, the hybrid computers won't put a load on the engine - unless you really floored it.

Does it lose 2 bars when you let the car idle until it turns off the engine, and then start your trip?

 

It's normal with a cold engine and exhaust system. Don't worry about it.

 

Yeah same thing sometimes happens to me Tom. I often lose just one bar whiles it's warming up, but sometimes I can lose two or even three depending on which way I go. One way I can go is up a big hill, and yeah if I just drive pretty slowly then it uses the battery a lot and often drops two bars, a few times it's even dropped three on me there.

Ususally if it's cold then the car automatically starts the ICE as soon as I start backing out of the driveway. Then if I drive very slowly along my street (which is a quite back street) I can give it a bit of time to warm up. Then if I use a bit more accelerator when I turn onto the main road it uses the battery a lot less and may not drop any bars at all.

So yeah it depends on which route I drive on leaving the house, but definitely it uses the battery more in the first few minutes while the ICE warms up, so losing a bar or two is not at all uncommon.

 

do you ever see the battery at full bars? I get to green, but I can't ever seem to "fill" that last slot.

thanks

 

Same as with other cars, it's easier on the engine to drive gently for the first minute or so until it warms up. After that, it's most efficient to *avoid* using the battery as much as possible. Short path fuel economy zen:
- better to glide (no arrows on the "energy" display) than coast
- better to coast than brake
- better to brake than stop
- better to stop than run into something
Ideally one would zoom up to some maximum speed less than about 42 MPH, then glide all the way to the next stop. In practice of course this is usually completely impractical if not impossible. Zooming up to 42 MPH and cruising is more feasible. On the freeway you just gotta go with the flow.

 

When you say that it loses two bars at start up do you mean it does that without the arrow showing that the HD battery is being used and draining? If it does then you are using the HD battery and all is normal. If the arrow is going into the battery and it is going down two bars then I would say you have a problem. If neither arrow is showing then I have to ask what other electronics are running in your car. Keep in mind that the HD battery can also be used to charge the 12 volt battery if low. Is something draining your 12 volt battery at night? Lights on?

You also don’t say at what level the bars were when you lose two. If bar 8 or 7 were on (green bars), they would be used up quickly because the Prius likes to keep the charge at around 60%. If you were at 6 bars and it goes down to 4 bars when starting out I would wonder why it is doing that, unless you are really pushing the car hard when starting out as other have said.

 

This typically will happen as you are descending a hill. Probably need to drop 1,000 vertical feet or so.