Carmageddon said:
Prospective buyer here.
I read like 5-6 pages from this thread, and cant understand what is the conclusion?
I am comparing to the Tesla Model X, their batteries have very negligible degradation, people say 5, max 10% or so.
Are you guys saying here you see 20-30% degradation, and having to fight to get warranty service (just to see it degrade severely again in a few years)?
If so, that sounds like a turn off, despite the much better pricing compared to the X...
Well you have to realize what you're dealing with in a PHEV. Batteries are generally good for around 500-2000 cycles (discharging to 0% and charging to 100% is 1 "cycle"; discharging to 50% and charging to 100% TWICE is also 1 "cycle"), depending on a number of factors. https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
1. Cutoff voltage (lower is better). The lower the charge voltage, the more cycles you get.
2. Depth of discharge (lower is better). Going between say 50% and 75% repeatedly is way better than going between 100% and 0% and gets you many more cycles.
3. Temperature (li-ion batteries like the same temperatures we humans do. Elevated temperatures that make humans sweat are especially bad for them).
4. C rate (how quickly you discharge or charge a battery relative to its capacity). Lower is better. Discharging at something like 1C (discharges or charges battery completely in 1 hour) is generally okay. Anything way over that, say 3C (would charge or discharge the entire battery in 1/3 of an hour or 20 minutes) is really bad for the batteries. https://batteryuniversity.com/index.php/learn/article/discharge_characteristics_li
Tesla carefully controls all 4 factors to ensure battery longevity. Consider:
1. Tesla allows the user to tell the vehicle to only charge the car to a certain level for daily driving (typical values people select are between 60%-90%). The batteries are then only charged to 100% just before a long trip, when the capacity is needed.
2. Teslas have huge batteries. Not many people drive > 300 miles in a day. Thus, the % of power used before they reach a charge station is low, and depth of discharge is low.
3. Teslas keep their batteries cooled on hot days, even when they aren't plugged in, unless the power level drops below a certain threshold.
4. Teslas have large batteries. When you have a 100 kWh battery but it only takes 25 kW to cruise down the freeway, you are only discharging that battery at 0.25C
Also, let's say that battery is good for 2000 cycles. In a Model 3 or Model S with 310 miles of range, this means the battery is good for 310*2000 = 620000 miles. The darn car isn't going to last this long. Something else is going to break before the battery does!
Now on a PHEV, the situation is basically the opposite.
1. Many PHEVs, the Outlander included, don't allow the user to limit the charge level. The thinking is probably that the range is so short, the users need all of it on every trip. I've figured out a way to manually cut off the charge when it reaches a certain point by calculating how many kWh per bar on the gauge, and telling the EVSE to stop charging when it reaches a certain number of kWh, but this is the exception rather than the norm.
2. PHEVs have small batteries. Most people drive more than the range of the battery in a day, and thus, put the battery through a lot of cycles in a short amount of time.
3. PHEVs don't have the spare power in their batteries to cool their own batteries when parked outside on a hot day. The Outlander DOES have a battery cooling system, but it only operates when the vehicle is switched on.
4. When you accelerate in the Outlander PHEV, it often takes 30-50 kW of power. It's for a brief moment, but you're discharging that battery at around 3-4C when you do this. In order to discharge a Tesla's battery at 4C, you're basically talking launching the car in ludicrous mode (which needs 300-500 kW of power). How often do you typically do that? Yeah, I thought so. If you are cruising down the freeway and you're not in Save mode, you're consuming way more than 12 kWh of power. I mean, the battery is a 22-28 mile battery and you're doing 50-80 mph typically. That means you're draining the whole battery in under 30 minutes, which is an over 2C discharge rate.
All of these factors combined mean that your PHEV battery likely isn't going to last the life of the vehicle, while a Model X battery IS likely to last the life of the vehicle. Even if we assume that the PHEV battery lasts for the same number of cycles as the Model X battery (which is unlikely because of the above 4 factors), we're talking 2000 * 25 = 50000 miles.
:lol: 
