I love my Prius. Sometimes I think it was made/designed just for me. Now that the Midwest winter has set in, I know the drain on the battery is more than normal. So here's my question: To anyone's knowledge, is it possible to totally deplete the battery if one drives *every single day* but rarely more than 2-5 miles at a time, if that? Thanks.
No. The computer protects the battery. The battery meter you see on the screen isn't the full range of the battery. So 8 bars really isn't full (it's only 80%) and 0 bars really isn't empty (it's 40%). If anything, I would say your battery would be holding MORE charge because your engine would be running to warm up and it'll charge the battery. IOW, it's quite possible that you'll see more green batteries than you did over the summer.
No, it's not possible...One of the primary jobs of the car is to preserve the battery at all costs....it would sooner slow the car to a crawl using spare power from the ICE to replenish the battery before it let it die.... The only way to drain the battery on a normally functioning car would be to drive in an out of gas condition...and even that there is much doubt as to the possiblity of draining below 20%SOC. The other would be to leave the car in Neutral and Ready mode constantly until the battery drained as there would be no means of recharging.
I thought that some people had depleted the main battery to the point of needing it replaced by driving it while out of gas. I have also been warned about my bad habit of leaving the car in N while the A/C is running, another anomaly which will allow the main battery to be depleted beyond its intended point. I have of course stopped that before anything bad happened. Also, I thought that during the warm-up time period, under normal circumstances, the car is actually using power from the battery to move the car, if you choose to drive instead of sitting.
<div class='quotetop'>QUOTE(efusco @ Dec 3 2006, 10:02 PM) [snapback]357177[/snapback]</div> You appear to be referring to the main battery, right? Is this *also* true of the 12 volt battery which powers the MFD & actually starts the car? The one which recognizes the SKS? And if in fact this battery could be affected by low mileage daily driving, how long would it take to recharge it (& how) if it failed to start the car? I'm no car whiz so perhaps I wasn't as clear as I could have been when posing my question. Again, thanks. It's people like you, Tideland, & sub3 who make the purchase of any otherwise potentially intimidating but otherwise fantastic car accessible to ordinary people like me.
<div class='quotetop'>QUOTE(sub3marathonman @ Dec 3 2006, 07:16 PM) [snapback]357200[/snapback]</div> Yes it does, initially. After that, when it actually assists in moving the car, it wil still run when you come to the next traffic light. It's that situation when the engine will charge the battery. <div class='quotetop'>QUOTE(Starfall @ Dec 3 2006, 08:19 PM) [snapback]357211[/snapback]</div> If I may speak on his behalf, yes he's referring to the "main" battery (it's sometimes called the traction battery or the HV battery). I'm not sure about the 12V but it should operate similarly to any other car. Just note that it is a bit smaller so avoid running accessories without the car on (i.e. in READY mode) for an extended period of time.
<div class='quotetop'>QUOTE(sub3marathonman @ Dec 3 2006, 07:16 PM) [snapback]357200[/snapback]</div> This is true, under normal circumstances. It does this to protect the engine by keeping the load on it light while it is cold. However, if the battery is too low or too cold to provide enough power or if you call for more acceleration than the battery can provide, it will then use power from the engine. The car will protect the battery whenever necessary. If the battery has enough charge, it will draw from it to go easy on the engine while it is cold. It is not good for any car to drive it such a short time that the engine never gets warm. I'm guessing that 2 to 5 miles should be enough for the engine to get warm??? And I think that after 1/4 to 1/2 mile the engine is warm enough that the car will start recharging the battery. As Tideland says, you will probably see your battery nearly always near its upper range, as the engine never gets hot enough to get to stage 4 (full hybrid) operation and shut itself off. And you'll get relatively low mileage especially in cold weather. And never leave the car in neutral. There is always some drain on the battery any time it is on, and in neutral the car cannot charge the battery.
<div class='quotetop'>QUOTE(Starfall @ Dec 3 2006, 07:46 PM) [snapback]357158[/snapback]</div> If you are referring to the 12V battery, the answer could be 'yes'. In month 3 of my car's life, after I'd been doing only very short trips, I accidentally left a door slightly open all night. As a result the interior light was on and the 12v was flat in the morning. Another possible cause was that I had topped up the tyres on the previous day with an electric inflator. Anyway, it was a good learning experience and I now know how to use the emergency key and how to jump-start without opening the back door. After this I always make sure the doors are shut by locking the car at night (it won't flash the locking lights if a door is slightly open). I also switch off the interior light in the summer or if I'm not using the car much in the dark.
Also in answer to one of the questions, yes, some people have driven their battery into the ground - but that was only when they ran out of gas/left it in neutral and really tried to push it hard to get that extra mile to the gas station. I'm not sure if the batteries had to be replaced or not, but i do know that in several cases they had to be taken out and put on a special wall charger (because they were drained so low). So long as the car is turned on, not in neutral, and not out of gas, you'll be fine.
The last thing you should worry about is the NiMH traction battery. Assuming you don't leave it in N, the car will look after it just fine. However if you search around this site, concern has been raised over the tiny 12 vdc auxillary battery. I know with mine, after a year the auto headlights would really dim in the underground parking once the coolant pump cycled. I have a few VDC Battery Minders and I used the ring terminal harness, with an inline 3 amp fuse, hooked directly to the 12 vdc battery. In my parking stall a power recepticle is very conveniently located on the wall, and the condo association doesn't mind if I use it. So whenever I'm parked at home I leave the car plugged into "shore power" so the Battery Minder can condition the 12 vdc battery and keep a float charge on it. The first time I used the Battery Minder, I was away for almost a month on business. I just took out the 12 vdc battery, and plugged it into my other Battery Minder in the condo. There was a very apparent difference when I returned. When I powered up, the headlights barely flickered when the coolant pump cycled. Another thing I've noticed is that the coolant pump is quieter. When the 12 vdc battery was only keeping around 11 volts, the pump would moan and groan. Now I can barely hear it.
The 12V battery is not at significant added risk in the winter; it takes hardly any more power to boot a cold computer than a warm one. The only way to kill the 12V battery is to do something dumb, like leaving the dome light on or the hatch ajar. (*Always* lock the car, by the way, because if you have done any of the common dumb things the car will warn you with a long beep when you try to lock it.)
<div class='quotetop'>QUOTE(richard schumacher @ Dec 5 2006, 02:50 PM) [snapback]358079[/snapback]</div> By the time you get down below -20 C, especially towards -40 C, a battery is only putting out around 20% of the power it had at +20 C. If anything is marginal, by the time the brake boost pump and coolant transfer pump do their cycle, you might be dead.
<div class='quotetop'>QUOTE(jayman @ Dec 5 2006, 03:33 PM) [snapback]358177[/snapback]</div> But if the battery is only able to output 20% power, how will it be dead after the pumps do their thing. I would imagine they just wouldn't get the full current. The computer doesn't need too much current to get it started so I don't think that cold weather should be an issue. I don't think I've seen any post on hard starts in the winter.
Both the brake booster pump and the coolant transfer pump appear to draw a lot of power. When my Prius battery was acting up, the auto headlights would REALLY dim especially when the coolant pump engaged. Once, last December, there was a click, the headlights went out, then turned on again very dim. Finally, when the HV relay closed, they immediately went to full brightness. That got me worried. Since the HV relay closing is among the last things to happen before you transistion to Ready, if voltage should happen to sag too much, the relay cannot engage. A marginal battery, affected by extreme cold, might go too low to allow the relay to close. Even Battery Council International admits cold weather dramatically reduces battery output http://www.batterycouncil.org/BCIwinterbat...carerelease.pdf It's not that the energy in the battery has magically disappeared. Extreme cold can slow down the chemical reaction. In a place like Siberia, by the time you get to -60 C or so, a battery won't even work. Note: Since I started using my VDC Battery Minder full time on my Prius last December, there has been a dramatic difference in behavior. Now when I power up in the underground parking, the Auto headlights barely flicker
<div class='quotetop'>QUOTE(jayman @ Dec 5 2006, 04:55 PM) [snapback]358218[/snapback]</div> Brrrrrr!
Daniel No kidding brrrr, if your lips would even move and not be frozen. Naturally there is Permafrost in that region, and in part the bitter cold is caused by mountains funneling arctic air down to the high plateau. Apparantly rich in coal, gold, and uranium deposits. http://news.nationalgeographic.com/news/20...tvoymyakon.html I couldn't hack it - bad enough right here. jay
