Markabele, what don't you get? Perhaps my lifestyle is not regimented? I don't get in the car the same time every day and drive to work. I also work from home. I have client meetings I have to drive to. I teach two days a week. My decision to not set up the edison plan where charging at night would be the cheapest was based on this fact. And that the Prius battery is so small that I would be charging it at all times to get max mpg. My goal in life is not to be mashing buttons to estimate when I'm going to be leaving next. Bah humbug.
The wikipedia page for lion batteries, "Lithium-ion battery - Wikipedia, the free encyclopedia", notes "Batteries may last longer if not stored fully discharged. ... It is recommended to store batteries at 40% charge level." with the element marked as 'dubious -- discuss'. The controversy is that there is a web site, batteryuniversity.com, which seems to draw upon unscientific sources but is widely quoted. I looked at a couple of references, and they seemed to suggest 40% or 50% for storage, although the 50% might well be a transcription error. As for the manual, mine is online at http://www.toyota.com/t3Portal/document/om/OM47866U/pdf/1.pdf . It only states "By using the charging timer function, deterioration of the hybrid battery (traction battery) charge can be suppressed, and off-peak electricity can be used effectively." What I conclude is that for the normal 25% - 85% discharged to HV / fully charged range, it really isn't significant. If we were charging to 100% or fully discharged to 0% my answer would differ. And if there was a feature that would charge to 40% and then hold it there until a just-in-time charge to my expected ETA, I'd use it. But it seems like the more compelling use of deferred charging is to make use of off-time power usage.
li-on comes in many varieties. i think i'll trust toyota's knowledge of their proprietary chemistry over generic wiki.
The tech manual (https://techinfo.toyota.com/techInfoPortal/staticcontent/en/techinfo/html/prelogin/docs/priusphvdisman.pdf) seems to indicate HV Battery Pack * The HV battery pack is enclosed in a metal case and is rigidly mounted to the cargo area floor pan cross member behind the rear seat. The metal case is isolated from high voltage and concealed by carpet in the cabin area. * The HV battery assembly consists of 3.7 Volt Li-ion battery cells connected in series-parallel circuit to produce approximately 207.2 Volts. Each Li-ion battery cell is non-spillable and contained in a sealed metal case. * The electrolyte used in the Li-ion battery cell is an organic solvent containing lithium-ion. The electrolyte is absorbed into the electrode and will not normally leak, even in a collision. HV Battery Assembly * Battery assembly voltage 207.2 V * Number of Li-ion battery cells in the battery 56 cells * Li-ion battery cell voltage 3.7 V * Li-ion battery cell dimensions 4.13 x 5.83 x 1.04 in. (105 x 148 x 27 mm) * Li-ion cell weight 1.60 lbs (726 g) * Li-ion battery assembly dimensions 29.4 x 37.3 x 6.9 in. (747 x 948 x 176 mm) * Li-ion battery assembly weight 168 lbs (76 kg) This seems fairly generic, and I would think that generic would be a feature in this case, as it means it takes advantage of well exercised technologies. What leads you to believe they have a proprietary chemistry? I don't think we are disagreeing about the desirability of charge, just a matter of degree. The manual seemed previously to talk about discharge more (note that they *just* changed from NiMH to lion) and in the current manual just casually mentions it in a compound statement that also touts making use of off-prime electricity costs.
This is how I weigh it in my head: pressing a button or two and doing a little planning in my head or even a chance that one of the most expensive components in the car could have lower life expectancy by charging it immediately and letting it sit for hours and hours "full" to me it seems like a no brainer...but then again, I have been accused of having no brain
I'm always surprised by how many people drive on a schedule with no unexpected trips. That is not how my life works, which is why I plug in when I get home. I might have to run to the store, or get a call to meet friends for coffee, or who knows what. When I plug in I get to use EV for those trips, significantly boosting my EV ratio and overall mileage.
You're forgetting to include the increased pollution and decreased EV ratio caused by any trips you take after parking your car but before the charge timer came on.
Interesting. I agree with this. It's the opposite no brainer for me, though. Seems like a waste to schedule your life to the 2.5 hours just for the chance it may be detrimental to the battery. Now if your life was routine like most weekdays, it's a simple button. I have to set a routine to earn a living on weekdays but I'd rather my weekends not be as structured. I'm also been accused of having no brain. iPhone ?
Totally understand your guys' need to have it ready at a moments' notice. I actually have some situations like that. But it's so very rarely a situation where I just have to leave that moment. Usually something gets planned for 1-3 hours in the future. And it really only take a little over 1.5 hours to get the bulk of your charge in anyway.
i don't know who makes it or where, but i believe toyota is closely involved with development and testing. if they recommend not leaving it charged, i have more confidence in that than in a generic wiki article about li-on batteries. i have no problem with you leaving your car charged all the time, i am simply answering the o/p's query. why is everyone who leaves their battery charged so worked up? you can do whatever you want.
I'm not worked up. I just don't want people to miss out on EV mileage because they're under the impression that they'll damage their battery pack by charging and not driving. Lithium chemistry is what it is no matter who makes it, whether it's in a PiP or a laptop. You don't leave your laptop battery dead until right before you're going to use it do you?
I don't get what? That some people imagine Toyota has found a way to make the chemical properties of lithium different than it is for everybody else who uses the periodic table?
