Does my hybrid battery need replacing?

Hallmark of hybrid battery failure, aside from the big red triangle of death, is the hybrid battery fan running on high, especially when starting the car only an hour or two since its last trip. I think it is more likely that your 12V battery is bad. If it sat at a car dealer for a while, chances are they let the battery die, and then jumped it for your test drive. Follow this thread, tomorrow morning, to do a test.

http://priuschat.com/forums/newbie-forum/73400-weird-stuff-happening-mpgs-dropping-test-battery.html

 

Everything sounds 100% normal there piper. The SOC (state of charge) is by design meant to stay in the blue most of the time. The 7th and 8th bars are basically there so that it has spare capacity to regenerate down hills etc.

Six blue bars is the ideal level that the system tries to keep the battery at, though you can expect it to some times drop a bit lower under heavy A/C usage or when it runs in full electric mode under light accelerator pedal conditions.

Whenever it's green (7 or 8 bars) it's actually got too much charge so the computer tends to make it use more traction electric power and usually within a few minutes of normal driving it will be back at 6 blue. This all 100% normal.

I think you'll find that it hasn't dropped down to 2 bars while it was sitting but it has dropped after you started it. This is also quite common and does not necessarily indicate a problem. It's due to the high demand on the battery when you first start, particularly if you have the A/C on full and if you drive before the engine is warmed up a little. When the engine is cold it will try to run on only the electric motors for about the first 40 seconds (even though the engine is running!), particularly if you're easy on the gas pedal.. This happens to me a lot, where you loss a couple of bars of SOC right in the first 30 to 40 seconds after starting.

The solution (and this will definitely reduce the strain on your battery and give it the best change of long life) is just to let the car warm in park (in park is important) for about 30 to 40 seconds before driving off. I find this especially useful if you have to climb a hill straight away. BTW. With your foot on the brake you can just tap the gas pedal to make the engine come on. If the car is already warm enough then the engine will just cut out straight away, in this case just drive.

I should point out that some people here disagree with this idea, but try it and I guarantee it will stop your battery from draining so much when you first take off.

 

Another tip to ease the load on the battery at start up is to (if you can bear the heat) put the windows all the way down instead of using the A/C, just for the first two minutes to flush all the hot air out, and then put the windows up and the A/C on recirculate at temperature set point of about 75F.

 

You meant that it will regularly flick between the various states of "no arrows to the battery", "charging arrows the battery" and "discharging arrows from the battery". Yeah that's normal when you're cruising.

 

At 70 mph there is little extra horse power to charge the battery. Other factors also come into play. So, it only charges when the battery is down to two bars or when you decelarate.

Watch out that you don't go "Prius blind" - watching the display and not the traffic.

 

piper180, I would watch that 12v like a hawk. Check in the morning after sitting over night. Mine normally reads 12.6v. Low 12v can cause night- mares. Hal

 

I know I've posted this link before, but if you have doubts about the longevity of the Prius HV battery you might want to read/watch the following about a Canadian Prius cab that reached 1 million km (about 800,000 miles);

CTV British Columbia - Hybrids prove very reliable - CTV News

 

Hi I agree with everything above except rh reciric bit. Not because it's not effective but because running recirculated air for a long time in a motor vehicle is dangerous. Motor cars, even Hybrids, are fume machines. Carbon Monoxide is odourless. Evaporating plasticisers are also almost odourless.

Yes, occasionally the air outside is worse than inside.

 

Sounds like the 12V battery is just fine as well, if it started the car after it sat for six days.

Because it was dead when you got the car its' life has been shortened, but it sounds like it's fine for now. Be aware it's not an inexpensive battery you can pick up just anywhere. When it's time, I'd recommend thinking about the eLearnaid Optima replacement http://www.elearnaid.com/12vo1topraub.html. It's about the same cost as the Toyota battery but probably a bit better at resisting full discharge damage. They can get it to you in the US in a day or two.

 

after enginer install the soc is always 9 green bars. Is this not hard on battery life Don

 

There are only 8 bars, so yeah that's bad.