BabyLFA

has anyone been on a road trip with the 450h+ for more than 6 hrs or so, and use the "hold charge" button to recharge the battery for EV range? Just want to know if it's even worth it or just use HV mode the whole way?

nx450plus

I used the Hold Charge function around town for about 3 km on a 50 km/h street to see what it would do. The fuel consumption was about about 2 or 3 times what I would expect on HV mode. It is running the ICE engine hard to charge the battery. It did it's job as there was a bit of extra EV range gained. I would not recommend Hold Charge because the cost of fuel versus the range gained is not worth it.

timdakao

I think the purpose of the Hold Charge function is extremely circumstantial. The only use cases I've see reviewers come up with is that there are some small towns in Europe that only allow EVs, so if you know you're going to be passing through one and you're low on charge you can charge up, or if you're going to be doing some off-roading or mountain trails and you want to take advantage of AWD (the rear drive is run by the electric motor only) then you can charge up. Otherwise for a regular road trip or normal daily commute it's not worth it to use the hold charge feature.

scooky

Agree, likely very circumstantial.
Zero emissions city zones.
I've heard, no personal experience yet, that some phev benefit from saving the battery for a long mountain climb. I think I saw it in a video, seems plausible, but might not be relevant.

lsft

From what I do observed, it's not worth it. Driving HV is more efficient than driving with Change Mode on. I ran it for 10 mins driving 100km/h and gained 5 km.

Keep in mind... It's called charge mode. It's hold the button down to charge. 😛

Htrain

But in an emergency, its a 'life saver'. By mistake on a recent road trip I forgot to change the mode from EV to HV and at the next 'pit stop' was shocked to see the range indicator of the battery as dashes. Im in BC out in the 'boonies' (no charging station even close). Then I remembered and put it in the charge mode and within 40km had enough battery range showing to go back into HV. Yes the fuel efficiency sucked BUT even at the 10.3 l/100km (on that hwy trip HV efficiency was 4.1) it gave me peace of mind.

BabyLFA

That's a good idea, preserve EV range on start of the trip, and just use HV until you're within range of driving home. I'm gonna do that next trip.

ct6978

I used it when I first picked up the car (it was delivered with 0 EV range) and had to drive up over mountain passes on the way home... I wanted to avoid stressing the new engine.

Used a lot of gas to charge the battery slowly, I think I may have dropped 5-10 mpg on that part of the drive. Not sure I can see too many use cases for this, other than those already mentioned. The amount of gas used seemed much more than the ICE driving range for the same amount of gas.

CdO

I wondered about the charging rate. This, of course, is not limited by the 3.3kW or 6.6kW onboard charger. The ICE charges the battery using the 31kW rated "Motor/Generator 1"; so, this could (theoretically) provide enough power to charge the battery in ~30 minutes.

Five km in ten minutes would mean a full charge in ~2 hours. It would be interesting to know what the max charge rate is in this mode. It would give us insight into what Lexus thinks is the highest safe charge rate. Maybe this could ease everyone's fear of battery degradation when charging at 6.6kW (2.5hrs). The 2.5 hour charge rate is actually quite low at 0.4C; some EVs are charging at or well above 2C until 80% SOC.

Perhaps a deeper dive of this could be your next youtube video... for science!

lsft

Theoretically, It is 2.5 hrs and that would be similar to the 6.6kW charger. Which means it does not use the full 31kW MG1. Keep in mind when you using charge mode, you are also driving so the MG1 is operating the vehicle as well. I don't have much background on EV charging, but I agree that the 6.6kW charging is really not fast charge. Super chargers are much faster that the capable 6.6kW. Also keep in mind that the charge mode can only charge the vehicle up to 80%. Once it reaches 80% charge mode will stop.

CdO

I won't hold you to the 5km in 10 minutes; but, that's 60km in 120 minutes, no? 150 minutes would give 75km? ...or do you get 75km EV range?

In charge mode (and HV), the ICE can directly drive the front wheels (less the reduction gearing) while MG1 is stationary (at vehicle speeds above something like ~60km/h). MG1 starts the engine, charges the battery, and provides the "eCVT" ** functionality. MG2 (and MGR for AWD) is used to drive the vehicle (and for regenerative braking). It is physically possible to use MG1's full power to charge the battery (at certain speeds). I also wonder where they draw the line on the rate of regenerative braking.

**I don't like that they call it an eCVT. It's physically nothing like any CVT that anyone might be familiar with. It's far more clever and reliable ...and difficult to explain.

Anyway, if I actually get one of these cars I'll see about updating my TechStream and digging around to see what I can see.

lsft

My bad, I just watched my video again. I had 2 km of charge when I activated Charge Mode and gained to 5 km in around 9:40 driving 85km/hr. So gained 3km in 10 mins - so 36km in 120 minutes. But Charge mode can only charge up to 80% and not beyond that.

CdO

No worries, thanks for double checking. Unfortunately, that's a more disappointing rate.

Thinking more about how it works... it seems that it would (be able to) charge faster the slower you are going (not because of lack of engine power; but, just because of how it is configured). At higher speeds it may only charge (using MG1) with the ICE at very high rpm. It could charge at any speed from ICE by using the 40kW rear motor (MGR)... or MG2 would be better; but, it doesn't sound like it does. There are so many ways that it could work; but, I'd like to know how it actually works.

ct6978

The one time I used it, it seemed to charge relatively slowly at highway speeds, although I didn't measure it and had just picked up the car, so limited frame of reference. I got the car with the battery depleted and was going to be driving up several mountain ranges and used it so I was able to use the motor uphill and not strain the new ICE. I think my first stint was about 65 miles/ 1.5 hours and that got me into double digits range, enough to make up the first large grade fine.

CdO

Exactly, this is the most common use case I have considered. I haven't come across a "When to use CHG Mode" thread (yet). I initially thought to use it exactly as you describe; but, after learning more... I'm not sure. It may be better to charge (if possible) before you get on a highway with upcoming steep passes, even though EV Mode is normally preferable in low speed environments.

I see there is a "Predictive efficient drive (predictive deceleration support)" (for mainland US). It uses nav data to boost regen in registered downhill areas when the accelerator is released. It doesn't say anything about preparing for (or adapting to) uphill areas (even though the downhill and uphill data are effectively the same data).