can you force no drive-battery charging while driving?

[anko]

I understand and agree with most of what you write. What I do not understand is why you spent a lot of money on an expensive PHEV battery when you don't plan on using it as a PHEV battery. If you plan on using it (the car) as a HEV battery, could / should you not have bought a cheaper HEV? Also, with your way of using the car / battery, why would you be concerned with degradation of capacity? You seem not to be using the capacity anyway.

Also, I don't understand why you insist that Save mode prevents high discharges on the motorway, where it is really your hight speed that prevents these high discharges. Would you not agree that if you did not charge your car externally at all and allowed SoC to hover around 30% all the time, you would not see high discharges on the motorway either, with your driving pattern? Seems a bit pedantic, I know. But I think we should not assign properties to Save mode that are not really specific for Save mode, as other people may get wrong ideas about what Save mode really is. Until you prove me wrong, of course. That is always a possibility ;-)

 

[elm70]

...
PHEV drivers on the other hand really tend to beat up their batteries. Because the batteries are smaller than those for BEVs, they not only discharge at high C rates for extended periods of time (like at 2C for if driving on the freeway in our Outlanders using 24 kW without using Save mode, while the huge size of the batteries in BEVs mean that even using 24 kW, you are only discharging the 100 kWh battery in a Tesla P100, for example, at 0.24C.), but they also are barely enough to supply power for our daily drives, and many times, not enough. Therefore, a lot of people drain the batteries to the maximum allowed, then charge them up to full, every single day, and sometimes multiple times per day. The BMU obviously tries to protect the batteries by only allowing discharge to 30% and stopping charging at around 85%, but there's really only so much you can do with a usage pattern like that. So by using Save mode on the freeway, I'm also trying to manage degradation in a way that preserves my battery for the long term. Yes, it's probably a little more expensive to use the ICE on the freeway compared with using electricity, but that neglects the cost of the battery itself. As a critical drivetrain component, as well as an expensive component to replace, I'd rather preserve it to do what it does best (powering the car on surface streets), and use the ICE during times it's reasonably efficient to do so. If you calculate the cost of battery replacement from allowing a high DoD every day, I suspect that the calculations would show that it's not worth it to burn electricity on the freeway.

I totally agree that our PHEV has a harder life then a battery on a Tesla

But I don't agree on your strategy on saving the battery.

If you are concern to use the battery on motorway .. just drive above 130km/h and the car will not use the EV battery

If this option is not possible .. plan to enter in the motorway with the battery "empty" (30% real SOC)

Let then the car do it's job automatically .. and the car will charge and discharge in the ideal battery state of charge that is around 30%

Pressing save .. will not make any difference ... but this will force to keep the battery in a SOC that is not ideal

PS: Checking over used battery pack for our PHEV .. I spot one here for just over 1000 euro ... and another one from a 2017 model for just over 2000 euros ... with more and more PHEV that will be crashing .. more and more 2nd hand PHEV battery pack will be available .. and possibly it will be not so expensive to find a replacement in case of need ... so ... in the worst scenario ... the cost for this replacement is not extremely high ...

 

[STS134]

I understand and agree with most of what you write. What I do not understand is why you spent a lot of money on an expensive PHEV battery when you don't plan on using it as a PHEV battery. If you plan on using it (the car) as a HEV battery, could / should you not have bought a cheaper HEV? Also, with your way of using the car / battery, why would you be concerned with degradation of capacity? You seem not to be using the capacity anyway.

The reasons are as follows:
1. PHEVs have tax benefits/rebates and HEVs don't. As such, the PHEV was actually about the same price as a HEV. So you could say that I didn't really buy the battery, the government did.
2. PHEVs get the HOV (carpool lane) stickers, which allow drivers to use the lanes even when driving alone. HEVs do not. This saves me time if it's carpool hours and there's a traffic jam.
3. PHEVs get preferred parking at malls, etc.
4. Free charging in public places is equivalent to a free gasoline drip (for which there is no equivalent for HEVs and ICE cars).
5. You seem to think I never use the full capacity, but that's not what I said. I said I don't use the full capacity on my regular commute. But when I do call on the battery to deliver its full capacity (and I do occasionally do this), I can get more out of it if I preserve it. This seems almost equivalent to asking someone why he/she bought a Tesla 100D when a 75D would be sufficient for his/her daily commute. But obviously, not all driving is just done between home and work...

Also, I don't understand why you insist that Save mode prevents high discharges on the motorway, where it is really your hight speed that prevents these high discharges. Would you not agree that if you did not charge your car externally at all and allowed SoC to hover around 30% all the time, you would not see high discharges on the motorway either, with your driving pattern? Seems a bit pedantic, I know. But I think we should not assign properties to Save mode that are not really specific for Save mode, as other people may get wrong ideas about what Save mode really is. Until you prove me wrong, of course. That is always a possibility ;-)

Most of the time I go on the freeway, I begin cruising at around 70-75 mph. I'll push it over 78 mph (125 km/h) when I get an opening in traffic. But obviously not all of my driving is done crossing gaps in traffic, and some of it is below 125 km/h. So I really do need Save mode to preserve the battery.

I have a friend with a Cayenne S E-Hybrid and one thing he started noticing was that his oil was smelling like gasoline. He did a used oil analysis and they did find high levels of gas in the oil. The reason? He wasn't using the ICE enough, and when he did use it, it was for only a short period of time. The engine was not reaching operating temperature and was therefore not burning off the gasoline in the blow-by. If you are going to use the ICE, it's better to actually use it for a long while rather than just using it for a short period of time and then shutting it off (which is what would be happening if it only operated when I was above 125 km/h), so that it reaches operating temperature and can burn off all of the stuff that it should be burning off. Actually, you may have noticed that if the ICE turns on, the Outlander PHEV tends to try to operate it for a certain period of time (3 minutes I think?) before it shuts it down again? I'm actually not sure if it's controlled by temperature or by time, but in any case, now you know why.

 

[anko]

Most of the time I go on the freeway, I begin cruising at around 70-75 mph. I'll push it over 78 mph (125 km/h) when I get an opening in traffic. But obviously not all of my driving is done crossing gaps in traffic, and some of it is below 125 km/h. So I really do need Save mode to preserve the battery.

No you don't.

 

[STS134]

Most of the time I go on the freeway, I begin cruising at around 70-75 mph. I'll push it over 78 mph (125 km/h) when I get an opening in traffic. But obviously not all of my driving is done crossing gaps in traffic, and some of it is below 125 km/h. So I really do need Save mode to preserve the battery.

No you don't.

Here are my measurements:

1. Using Save mode: consumes about 15-25% of the battery on the gauge (3-4 bars out of 16)
2. Using Normal mode: consumes about 40-50% of the battery on the gauge (6-8 bars out of 16)
3. One time there was horrible traffic as a result of multiple accidents along the route, causing stop-and-go traffic nearly the entire way. This consumed about 60% of the battery (9-10 bars out of 16). The reason it was so much higher than case (2) was probably because it was hot, and I was blasting the AC most of the way. Now in this unusual scenario, I will gladly just use the battery and go the entire way in EV mode alone.

 

[jaapv]

Most of the time I go on the freeway, I begin cruising at around 70-75 mph. I'll push it over 78 mph (125 km/h) when I get an opening in traffic. But obviously not all of my driving is done crossing gaps in traffic, and some of it is below 125 km/h. So I really do need Save mode to preserve the battery.

No you don't.

Indeed not. I think that the misunderstanding comes from not understanding that there is no fundamental difference between Charge, Save and no button pushed, except for the level at which the car will go into its charge-discharge cycle. (disregarding subtle differences in charging efficiency)
Running on Charge will cause the battery level to be high before getting to the switch-on switch-off point of the ICE, Save at an user-chosen intermediate level, no-button at the lowest possible battery level. But it will always get to its charge-discharge cycle. The whole point is to get home with a depleted battery, using the electricity for the times that the ICE is not efficient.

 

[Woodman411]

Most of the time I go on the freeway, I begin cruising at around 70-75 mph. I'll push it over 78 mph (125 km/h) when I get an opening in traffic. But obviously not all of my driving is done crossing gaps in traffic, and some of it is below 125 km/h. So I really do need Save mode to preserve the battery.

No you don't.

Here are my measurements:

1. Using Save mode: consumes about 15-25% of the battery on the gauge (3-4 bars out of 16)
2. Using Normal mode: consumes about 40-50% of the battery on the gauge (6-8 bars out of 16)
3. One time there was horrible traffic as a result of multiple accidents along the route, causing stop-and-go traffic nearly the entire way. This consumed about 60% of the battery (9-10 bars out of 16). The reason it was so much higher than case (2) was probably because it was hot, and I was blasting the AC most of the way. Now in this unusual scenario, I will gladly just use the battery and go the entire way in EV mode alone.

I wonder why in Save mode the battery still depletes by as much as 25%... perhaps ICE power alone is not enough for a/c or other functions?

Anyway, similar to STS, I'm leaning towards the Outlander phev not so that I can drive on battery power most of the time, but because the tax credits and rebates price it significantly lower than the upcoming 2019 RAV4 Hybrid which doesn't qualify for any. If there is any credibility to this article, how one preserves the battery makes a big difference to longevity, where it cites new batteries needed as low as 70,000 miles but can also last up to 400,000 miles: https://greentecauto.com/hybrid-news/hybrid-battery-replacement-cost

That being said, does anyone know the official Mitsubishi replacement cost (I'm assuming labor is included) for the drive battery? The article mentioned it was $2,299 ($3,649 for a new first- or second-generation Prius pack, but a $1,350 “core credit”) officially from Toyota for Prius, just curious if the Outlander phev was in the same ballpark (and has the credit for the old battery like Toyota does).

 

[STS134]

Indeed not. I think that the misunderstanding comes from not understanding that there is no fundamental difference between Charge, Save and no button pushed, except for the level at which the car will go into its charge-discharge cycle. (disregarding subtle differences in charging efficiency)
Running on Charge will cause the battery level to be high before getting to the switch-on switch-off point of the ICE, Save at an user-chosen intermediate level, no-button at the lowest possible battery level. But it will always get to its charge-discharge cycle. The whole point is to get home with a depleted battery, using the electricity for the times that the ICE is not efficient.

Not if you are trying to preserve the battery. In that case, the name of the game becomes to use the battery when it's most efficient to do so, and use the ICE when using it isn't too terribly bad (e.g. on the freeway).

I wonder why in Save mode the battery still depletes by as much as 25%... perhaps ICE power alone is not enough for a/c or other functions?

If you look in the user manual and/or in posts here, it says that Save mode only takes effect after the battery gets down to 80%. This is likely because it's better for the battery to be below 4.05V/cell most of the time.

Anyway, similar to STS, I'm leaning towards the Outlander phev not so that I can drive on battery power most of the time, but because the tax credits and rebates price it significantly lower than the upcoming 2019 RAV4 Hybrid which doesn't qualify for any. If there is any credibility to this article, how one preserves the battery makes a big difference to longevity, where it cites new batteries needed as low as 70,000 miles but can also last up to 400,000 miles: https://greentecauto.com/hybrid-news/hybrid-battery-replacement-cost

Yeah. And another way to look at this is: the government paid for my first battery through rebates and tax credits. But if I don't make it last the life of the car, they're not going to pay for another one. So it is in my best interest to make it last the life of the car. The guy in Australia, "Unplugged EV" on Youtube, beats the absolute hell out of his battery by discharging it the maximum the BMU will allow every day and charging it back up again. No wonder he's seeing so much degradation.

If there's one thing I'm pissed at Mitsubishi for, it's not allowing the user to set the charge limit. Tesla for example allows the user to set the limit in increments of 10%: https://teslamotorsclub.com/tmc/threads/charge-limit.107747/

I like to charge my battery to 12-14 bars out of 16 on the battery gauge, which is 4.00-4.05 V/cell (verified with OBDLink LX). But since Mitsubishi doesn't let us cap the charge at that level, I have to monitor the charging process in terms of how many kWh have been delivered, then hit STOP or go out to the garage and pull the plug at the right time. This can be easily calculated: 10 kWh for all 16 bars = 0.625 kWh/bar, and if you charge at 3.45 kW, you can calculate how many minutes, approximately, it will take to reach that level (well, minus the cell balancing procedure that the car seems to do at random intervals during charging). Still, this is annoying as hell that I have to do this at all, instead of just being able to change a setting somewhere in the car and let it charge on its own. I believe the charging system, by default, charges to around 4.10 V/cell, which is actually 85-90% of actual capacity. If you look at Table 4 on this page http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries, you can see what charging only to 4.00-4.05V/cell gains you in battery life: another 50-100% over charging to 4.10V/cell. So on top of the 400% expected increase in lifetime by managing depth-of-discharge, we'd expect my battery to last about 600-800% as long as one that's repeatedly discharged to the maximum that the BMU allows and then charged up to 4.10V/cell, which is what the car does by default.

That being said, does anyone know the official Mitsubishi replacement cost (I'm assuming labor is included) for the drive battery? The article mentioned it was $2,299 ($3,649 for a new first- or second-generation Prius pack, but a $1,350 “core credit”) officially from Toyota for Prius, just curious if the Outlander phev was in the same ballpark (and has the credit for the old battery like Toyota does).

I'm not sure what the replacement cost is. PHEV batteries are likely to be more costly than HEV batteries, which are usually in the 1.5 kWh capacity range. I know that the Porsche Cayenne S E-Hybrid battery is a US$10000 part.

 

[anko]

[I think that the misunderstanding comes from not understanding that there is no fundamental difference between Charge, Save and no button pushed, except for the level at which the car will go into its charge-discharge cycle. (disregarding subtle differences in charging efficiency)

I thought so too. Now I think he does understand that the behaviour in Save mode is pretty much the same as the behaviour in Normal mode with a depleted battery. But his concern is getting to a state of depletion. He doesn't mind depleting his battery to 30% slowly (at low speed), but he doesn't want to deplete his battery fast (at high speed). So, as long as he is going slow, he will allow the battery to run down and as soon as he goes faster, he tries to stay above 125 km/h to keep the ICE running and uses Save mode to 'fill the < 125 km/h gaps'.

Question is: is indeed the average (dis)charge current lower at lower speeds then it is at higher speeds, when you take into account the typical stop and go nature of slower travel? How often can you travel at a constant speed of 40 or 60 km/h for a long period of time?

 

[anko]

Not if you are trying to preserve the battery. In that case, the name of the game becomes to use the battery when it's most efficient to do so, and use the ICE when using it isn't too terribly bad (e.g. on the freeway).

Not use your battery in order to preserve it for what? Makes me think of these car bra's you see in the States. They are to keep your nose of the car in perfect shape. But for what purpose? You never get to enjoy it. Earlier you said it was like telling somebody he should not have bought a P100. Well, if somebody puts a speed limiter on the car, because it is bad to drive fast, then maybe it is better to buy a slower car.

I wonder why in Save mode the battery still depletes by as much as 25%... perhaps ICE power alone is not enough for a/c or other functions?

If you look in the user manual and/or in posts here, it says that Save mode only takes effect after the battery gets down to 80%. This is likely because it's better for the battery to be below 4.05V/cell most of the time.

When you are in Save mode a low water mark is set for the hysteresis cycle. When demanding power (for brisk acceleration or climbing or so), the SoC may drop below the low water mark then it will drag down the low water mark. As a matter of fact, it may go up a bit as a result of a long descent where there is a lot of regenerative breaking going on.

I like to charge my battery to 12-14 bars out of 16 on the battery gauge, which is 4.00-4.05 V/cell (verified with OBDLink LX). But since Mitsubishi doesn't let us cap the charge at that level, I have to monitor the charging process in terms of how many kWh have been delivered, then hit STOP or go out to the garage and pull the plug at the right time. Annoying as hell. I believe the charging system, by default, charges to around 4.10 V/cell, which is actually 85-90% of actual capacity. If you look at Table 4 on this page http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries, you can see what charging only to 4.00-4.05V/cell gains you in battery life: another 50-100% over charging to 4.10V/cell. So on top of the 400% expected increase in lifetime by managing depth-of-discharge, we'd expect my battery to last about 600-800% as long as one that's repeatedly discharged to the maximum that the BMU allows and then charged up to 4.10V/cell, which is what the car does by default.

After 5 hears heavy use my battery is crap. But I still get 30 km out of it. Your battery may be perfect, but you most likely also only get 30 km out of it, if you use it this way. At least I got to enjoy full range during the first few years

When I am totally honest, my EV has a hilltop reserve. Limits a full charge to 87%. Many days I don't need a full charge, and then I will use it. But when I do need a full charge I will happily disable it. With a PHEV is is a bit difficult to say "you need full range". If you artificially limit range and run out of it you will still make it home.

 

[STS134]

[I think that the misunderstanding comes from not understanding that there is no fundamental difference between Charge, Save and no button pushed, except for the level at which the car will go into its charge-discharge cycle. (disregarding subtle differences in charging efficiency)

I thought so too. Now I think he does understand that the behaviour in Save mode is pretty much the same as the behaviour in Normal mode with a depleted battery. But his concern is getting to a state of depletion. He doesn't mind depleting his battery to 30% slowly (at low speed), but he doesn't want to deplete his battery fast (at high speed). So, as long as he is going slow, he will allow the battery to run down and as soon as he goes faster, he tries to stay above 125 km/h to keep the ICE running and uses Save mode to 'fill the < 125 km/h gaps'.

Question is: is indeed the average (dis)charge current lower at lower speeds then it is at higher speeds, when you take into account the typical stop and go nature of slower travel? How often can you travel at a constant speed of 40 or 60 km/h for a long period of time?

Well, if we're just looking at averages, you can figure this out by how fast the gauge depletes, right? In stop-and-go traffic, the gauge depletes pretty slowly, as a fully charged battery gets around 22-30 miles, and it's about 1.3-1.8 miles/bar. If you cruise down the freeway at a relatively high speed, those bars disappear very quickly. I can easily lose half of the 16 bars on the gauge in as little as 10-12 minutes at freeway speeds, while on surface streets, it usually takes at least half an hour to get down that far.

Now in reality, stop-and-go traffic actually does cause surges of current both in discharging (acceleration) and charging (regeneration) directions. I typically see surges of around 60A (monitored with OBDLink LX) in either direction when accelerating or stopping, however, these are absolute peak values and are not a very high percentage of the time. Most of the time when accelerating or stopping, it's around 10-20A of charging or discharging current. When just cruising down the freeway at high speed, you'll see 40-60A or more leaving the battery continuously, without stop. As I mentioned before, high discharge currents are actually wasteful in some sense, because the amount of energy lost via internal resistance of the battery goes up as the square of the current...in other words, the battery more efficiently can supply low levels of power than high levels of power. Now in a purely economic sense, you'll probably find that electricity is still cheaper than gasoline, and it makes more sense to use the battery as much as possible, and always arrive back home with an empty battery if your journey is long enough (but that neglects the cost of replacing the battery itself, and this analysis only holds in a world where batteries are free).

 

[STS134]

Not use your battery in order to preserve it for what? Makes me think of these car bra's you see in the States. They are to keep your nose of the car in perfect shape. But for what purpose? You never get to enjoy it. Earlier you said it was like telling somebody he should not have bought a P100. Well, if somebody puts a speed limiter on the car, because it is bad to drive fast, then maybe it is better to buy a slower car.

If I get stuck in a 20 mile long traffic jam 5 years from now, my battery should be good to go the entire way. If I want to take a road trip and will do a full 22-30 miles on surface streets in EV mode, I'll still be able to do it.

When you are in Save mode a low water mark is set for the hysteresis cycle. When demanding power (for brisk acceleration or climbing or so), the SoC may drop below the low water mark then it will drag down the low water mark. As a matter of fact, it may go up a bit as a result of a long descent where there is a lot of regenerative breaking going on.

That's not how Save mode works. It doesn't set a "low" water mark, it sets a "desired" water mark, and then tries to maintain the SoC at that mark. I descended a long hill (called "the Grapevine" by locals in California), which is a 6% grade for about 8 miles. The battery charged about 2-3 notches on the gauge on the way down. But then the car kept the ICE off and quickly consumed everything it added, as it was trying to maintain the mark it had set earlier. I've also seen cases where the charge level depletes below the mark, due to heavy acceleration or going uphill. In that case, it will actually run the ICE, even after you are stopped, as it tries to restore the charge level to what it was before. If you want to maintain the charge that the car put into the battery when you descended a hill, you have to go out of Save mode and then go back into Save mode right after you get to the bottom of the hill, in order to have it memorize the new level. Perhaps a better name for "Save mode" would have been "Hold (at level set when you entered this mode) mode". Because "Save" implies that you're saving charge in the battery for later, and after you descend a steep hill, that's just not true. The car can and will consume that charge immediately unless you explicitly instruct it to memorize the new level.

 

[anko]

Well, if we're just looking at averages, you can figure this out by how fast the gauge depletes, right? In stop-and-go traffic, the gauge depletes pretty slowly, as a fully charged battery gets around 22-30 miles, and it's about 1.3-1.8 miles/bar. If you cruise down the freeway at a relatively high speed, those bars disappear very quickly. I can easily lose half of the 16 bars on the gauge in as little as 10-12 minutes at freeway speeds, while on surface streets, it usually takes at least half an hour to get down that far.

I can drive up a hill on one side and down on the other side. In the end my SoC may be the same but my battery has been rather busy. In other words, the average (dis)charge current is not relevant. It is the average positive value of the (dis)charge current that is relevant. The rate of depletion has little to do with that.

Now in reality, stop-and-go traffic actually does cause surges of current both in discharging (acceleration) and charging (regeneration) directions. I typically see surges of around 60A (monitored with OBDLink LX) in either direction when accelerating or stopping, however, these are absolute peak values and are not a very high percentage of the time. Most of the time when accelerating or stopping, it's around 10-20A of charging or discharging current.

10 - 20A when accelerating or stopping. In other words 3 - 6 kW? 60 amps as a peak value would translate into about 20 kw max, or 1/3 of the 60 kW the battery is rated for.

What tool do you use with your OBD Link MX? Is it EvBatMon or PHEV Watch Dog? (if not, I would be curious to learn what tool you are using). The sample rate for these tools is not overly impressive. When driving at a continuous speed / power draw, you will most likely catch the high(est) current. But high currents during brief acceleration or deceleration are easily missed.

 

[anko]

That's not how Save mode works.

Many people have reported this 'issue' in the past: selecting Save starts a hysteresis cycle of +/- 1.5% SOC. Intense driving conditions may force the SoC to go outside the 1.5% bandwidth. Once driving conditions have normalised, the car will resume the cycle, rather than try to return to the set low water mark.

You're in the US, so yours is a MY2018? Maybe they have changed the behaviour of the low water mark (or desired low water mark, if you want to call it like that).

 

[STS134]

10 - 20A when accelerating or stopping. In other words 3 - 6 kW? 60 amps as a peak value would translate into about 20 kw max, or 1/3 of the 60 kW the battery is rated for.

What tool do you use with your OBD Link MX? Is it EvBatMon or PHEV Watch Dog? (if not, I would be curious to learn what tool you are using). The sample rate for these tools is not overly impressive. When driving at a continuous speed / power draw, you will most likely catch the high(est) current. But high currents during brief acceleration or deceleration are easily missed.

PHEV Watch Dog. I looked into EvBatMon but it looks like that one hasn't been updated since 2016.

Many people have reported this 'issue' in the past: selecting Save starts a hysteresis cycle of +/- 1.5% SOC. Intense driving conditions may force the SoC to go outside the 1.5% bandwidth. Once driving conditions have normalised, the car will resume the cycle, rather than try to return to the set low water mark.

You're in the US, so yours is a MY2018? Maybe they have changed the behaviour of the low water mark (or desired low water mark, if you want to call it like that).

Yes, mine is a MY 2018. And that's the reason I use PHEV Watchdog instead of EvBatMon (which apparently hasn't been updated since 2016, and I'm not sure if that tool even works with the MY 2018 Outlander).

 

[anko]

Yes, mine is a MY 2018. And that's the reason I use PHEV Watchdog instead of EvBatMon (which apparently hasn't been updated since 2016, and I'm not sure if that tool even works with the MY 2018 Outlander).

I know Daniel is putting a lot of ongoing effort in PHEV Watch Dog. And he is doing a great job. But I am pretty sure that there is nothing specific for the 2018 in that tool.

In essence, these tools are not all that different. It is mainly the presentation layer that makes the difference. Like I said, both tools have a rather limited sample rate. I have a tool that has a much, much higher sample rate, and I see kW values of well over 40 kW (which must translate to at least 120 A) in city traffic. Reaching 50+ kW (or 150 A) is not that difficult. I guess your gauges must also tell you a different story?

 

[STS134]

I know Daniel is putting a lot of ongoing effort in PHEV Watch Dog. And he is doing a great job. But I am pretty sure that there is nothing specific for the 2018 in that tool.

In essence, these tools are not all that different. It is mainly the presentation layer that makes the difference. Like I said, both tools have a rather limited sample rate. I have a tool that has a much, much higher sample rate, and I see kW values of well over 40 kW (which must translate to at least 120 A) in city traffic. Reaching 50+ kW (or 150 A) is not that difficult. I guess your gauges must also tell you a different story?

Well, I see wild fluctuations in both amperage to/from the battery with small inputs on the pedals. And yeah, the sample rate isn't that quick, but I wonder if that's a limitation of OBDII. The thing probably wasn't designed to be queried many times per second for all of those parameters (OBDII was developed in what year?)

You can also see wild fluctuations in the power level gauges on the infotainment system. Reaching levels of 80 kW is pretty easy if you really step on it. Average values for current from the battery are probably easier to calculate than to try to get from the tool (but the tool can give you a rough estimate). You know how many miles or kilometers per kWh you're consuming, and therefore you know how many kWh per hour you are consuming. Convert that to kW, which is easy because 1 kWh/hour = 1 kW. Then divide by 318 or whatever the voltage of your battery is and you get the amperage.

So say your efficiency is 3 mi/kWh. If you are going 60 mph = 1 mile/min = 1/60 miles/hr. So (1 kW * hr /3 mi) * (60 mi / 1 hr). The miles and hours both cancel out, and you are left with 20 kW. 20000 W / 318 V ~= 63A. If you go 75, your average current will likewise be higher because speed is higher and efficiency is lower. You can easily draw 80A+ from the battery at those speeds and that's why it drains so quickly, but it usually fluctuates wildly, even if you use the cruise control, due to small fluctuations in the roadway (small inclines and declines in elevation).

 

[elm70]

Honestly ... I did monitor the battery temperature when driving on motorway in EV mode at around 120km/h

I did not notice any particular relevant increase of temperature ... normally +7 or 8 deg temperature increase ..

Still I'm not sure having a continuous cycle for charge and discharge will help to keep the battery more cool.
Still .. I would differentiate what to do in summer vs winter .. if the battery would be the concern

As said by Anko .. the battery is an item which will get consumed independently by what we do ... we can either consume it faster and gain on fuel economy ... or consume it slower and have almost no gain in fuel economy

My suggestion ... if the battery degradation is a concern ... just enter the motorway with "empty" battery ... the car will automatically charge and discharge the battery using the most efficient and battery friendly way

If you still want to take advantage of the battery on motorway ... maybe you can click and unclick on save at regular interval while driving on motorway .. it will discharge a bit slower the batter (or at least it will give some breaks) .. still if outside temperature is below 20c I would not bother ... only in hot days it can make sense to try to keep the battery "cool".

 

[Woodman411]

I wonder why in Save mode the battery still depletes by as much as 25%... perhaps ICE power alone is not enough for a/c or other functions?

If you look in the user manual and/or in posts here, it says that Save mode only takes effect after the battery gets down to 80%. This is likely because it's better for the battery to be below 4.05V/cell most of the time.

STS, so if I charge up to 14 bars (~80%)*, and then start up the vehicle and immediately press Save, and drive for 20 miles, would the drive-battery stay for the most part at 80% and the ICE run constantly for the 20 miles? Or during the drive, would the ICE start charging the drive-battery beyond 80%?
*The challenge I will have to charging up to 14 bars is not just to remember to unplug based on timing, but also the NY Winter season - the user manual recommends keeping the phev connected to a charger in cold temperatures so that the battery heater (is this the same heater used for the cabin?) stays on and presumably keeps the drive-battery at non-destructive temperatures.

I appreciate the references to battery-university (I had to read and re-read their articles to better understand) and your reference to Toyota Hybrids - I've lived with a 2007 Camry Hybrid and now a 2016 Lexus RX hybrid, and I think I better understand Toyota's reluctance to fully delve into the plug-in world. It makes more sense now - Toyota hybrids primarily use ICE and sparingly use drive-battery, not just because of the limited drive-battery capacity, but also because it's good for the ICE long-term (your Porsche reference is very relevant to me) and it's good for the drive-battery long-term, that is, to only use a small (or smaller) slice of SOC.

And yes, if and when I get my Outlander phev (or remote chance Hyundai Sante Fe phev), I will basically try to drive it like a hybrid, but with more bias towards using the drive-battery slightly more.

 

[STS134]

STS, so if I charge up to 14 bars (~80%)*, and then start up the vehicle and immediately press Save, and drive for 20 miles, would the drive-battery stay for the most part at 80% and the ICE run constantly for the 20 miles? Or during the drive, would the ICE start charging the drive-battery beyond 80%?

Pretty much. Now if you drive extremely hard, it may sink down below 80%, and if you descend a long hill, it may go above. But it will either charge it back up to or deplete it back down to the original level, which is the level it was at when you pressed Save. But a lot of the time I'm cruising on the freeway, I see it operating in series mode where it's generating power and immediately consuming it in the motors, or in parallel mode where it's sending ICE power to the front wheels directly. When it does this, the generator either operates at a fairly low power level (3-6 kW) or not at all (generator turns off, ICE runs and sends power to wheels only). This is exactly the same scenario that the OP asked about, and the short answer is that while you can't force the computer to only do this, you can make it do this under the right circumstances. Even when operating in series mode, I notice the engine revving up and down based on how much I'm pressing the accelerator (you can check with an OBDII scanner), so it appears to be mostly managing the power level so as to generate what it's consuming.

*The challenge I will have to charging up to 14 bars is not just to remember to unplug based on timing, but also the NY Winter season - the user manual recommends keeping the phev connected to a charger in cold temperatures so that the battery heater (is this the same heater used for the cabin?) stays on and presumably keeps the drive-battery at non-destructive temperatures.

I'm not sure if there's actually a battery heater, and if there is, whether it operates when the vehicle is powered off. The manual does say that the car can return some sort of notification that the batteries are too cold for use. I know that there IS some sort of electric heater, but I think that's for the cabin: https://www.mhi.co.jp/technology/review/pdf/e512/e512044.pdf

I appreciate the references to battery-university (I had to read and re-read their articles to better understand) and your reference to Toyota Hybrids - I've lived with a 2007 Camry Hybrid and now a 2016 Lexus RX hybrid, and I think I better understand Toyota's reluctance to fully delve into the plug-in world. It makes more sense now - Toyota hybrids primarily use ICE and sparingly use drive-battery, not just because of the limited drive-battery capacity, but also because it's good for the ICE long-term (your Porsche reference is very relevant to me) and it's good for the drive-battery long-term, that is, to only use a small (or smaller) slice of SOC.

I don't think that has anything to do with it. Toyota went down the path of fuel cell vehicles with the Mirai, and the hydrogen infrastructure just isn't there, and won't be any time soon. And the Prius Prime seems to be their first serious attempt at a PHEV (neglecting the earlier Prius Plug-In Hybrid which never really was advertised and didn't sell too many units). Getting the ICE up to operating temperature is certainly something that can easily be engineered, so long as the driver doesn't stop the car right after the ICE fires up. The bigger issue is how you deal with the whiners and complainers who see/hear the ICE come on due to heavy acceleration, vehicle heating being needed, etc., and then don't understand why it should continue to run for a long while after. It appears that it takes about 3 minutes of operation on the freeway (1500-3800 rpm) before the engine reaches operating temperature of 85-90°C. I would think it probably takes another few minutes before the oil reaches operating temperature as well.