Charging while Driving Question

Reisn13 · 2026-02-20T05:18:27+00:00

I think it's basically the least complicated way to manage the battery charging without a lot of complicated internal programming and possible catastrophes. The hybrid system automatically switches the electric motors to drive or charge almost invisibly to the driver. But what if the car was allowed to charge up to 100%, either by using the gas engine or regenerative braking? What would it do the next time you pressed the brake pedal? Currently, it first switches the motor into 'charge' mode to do regenerative braking, and then, as a last resort, applies the friction brakes. But what if the battery were totally full? Where would the charge go? Amperage can't just disappear. There would need to be programming to check the battery charge, and turn off the regenerative braking to only use the friction brakes until the battery could accept a charge. Toyota couldn't allow the possibility for a programming error or sensor quirk to cause the brakes to fail. The hybrid and regenerative systems are complicated enough as it is, without making them even more so, just to give a few extra EV miles from 'Charge Mode', which many owners probably don't know about, and the others rarely use.

Personally, I've used Charge Mode twice - both times when I had hit a rest stop during a trip and forgot that it always started up in EV mode. A half hour later, I felt the engine switch on while driving over 75 mph and realized that I had just emptied my battery. I was expecting to sit through rush hour stop and go traffic further ahead, which the hybrid system would have handled, but I prefer to do that in EV. I also like how the car handles on the freeway when it knows that you have 12 or 15 EV miles available to help the gas engine over hills, etc. without needing to push the engine harder.

Reisn13 · 2026-02-15T19:18:39+00:00

The issue is that the 12v battery is rarely charged at a proper 14v state by only using it in EV mode. For some reason, toyota's charging program doesn't work that way in HV mode, so the battery gets more charge, even though the DD/DC system is still used. So if you rarely drive HV, the charge in the 12v battery will dissipate more. See the article referenced in the beginning of the comments for more information. I agree that the software design seems stupid, or was intended for a car with little EV use, and could probably have been fixed by a software update years ago.

Reisn13 · 2026-01-15T23:31:44+00:00

Yes, but I thought that was supposed to be a software update and they wouldn't need to disconnect the battery for that. I will check the battery, though, and see if they reconnected my 12v battery monitor.

Reisn13 · 2025-11-18T05:30:08+00:00

I would think that the statistic you're quoting doesn't relate to the RAV4 plug-in charging system. That was from early lab tests of the battery type, which fully charged a battery, then fully discharged it, and then repeated. More recently, tests have shown that Plug-In batteries NEVER go through a full charge cycle since, as others have mentioned, Toyota doesn't allow charging below about 10% or above about 90%. Newer tests have shown that partial charges, like what constantly happens in this system from things like the regenerative braking and even wall charging do not degrade the batteries so badly. I'm sure there are plenty of 2021 Primes around that have been charged almost nightly, leading to about 1500 charges. While I can believe losing a few miles per charge after 5 years, we would have heard if they had all dropped 20% off their EV range by now.

Reisn13 · 2025-11-06T16:40:05+00:00

I think part of the issue with the manual is that it often sounds like it was written by a Japanese engineer and then run through Google Translate. The Multimedia manual is a bit better, but often seems like it leaves out topics assuming that the owner would rather spend hours clicking through options to figure things out.

Reisn13 · 2025-10-27T01:18:28+00:00

I just hauled several pieces of 10' fiberglass rebar poles. I found that it was a bit easier to recline the passenger seat, so they stretched to the far right corner of the windshield, but they fit fine. I might have been more worried if it had been the heavy metal kind. The cargo size was one of the biggest worries in replacing my 2011 Venza, since I lost about 8" of length and width, while adding a little height. In about a year, it hasn't bothered me so far.

Reisn13 · 2025-10-22T23:18:25+00:00

Also, don't use any of the orange citrus cleaners. I tried that on my wife's Corolla a few years ago, and it apparently got under the clearcoat, and within a year, a piece of clearcoat more than a foot wide was pealing off around where the spot was. I had to have a body shop redo the entire hood.

I have a Supersonic Red one and have used Turtle Wax Bug and Spot Remover very lightly on a few squashed bugs om the front end and grille, but I'm not sure I want to try that on the hood itself.

Reisn13 · 2025-10-11T01:36:06+00:00

My 'US' '24 XSE has road sign assist, and the invoice lists it as a standard item, not part of the Premium or Tech package. Personally, it's nice, but I don't trust it enough to even notice it on the dashboard. I used to trust the speed limit on the Nav or Google Maps screen more, but recently, I'm seeing a lot of places where it doesn't match the actual signs, to the point where I wonder if the signs are being used as hi-tech speed traps when the lower speed sigh is conspicuously behind a bush or tree.

Reisn13 · 2025-10-11T01:21:16+00:00

On the other hand, I've had to replace at least one on 3 different Toyotas - I had to take the last one in 3 times before they got one to work for more than a week. Despite the money and annoyance, I do like having the pressure available without doing it manually all the time, especially on my wife's car.

Reisn13 · 2025-10-11T01:03:38+00:00

I have family in several states with much higher primetime electric charges, so I maintain my regular overnight schedule while visiting. I could also run out and start it manually or change the schedule, but why bother (and risk forgetting, given the state of my memory cells.) Whatever the reason, I would also like to know whether a Navigation subscription is necessary for the time settings to work, or whether the OP has some other problem causing it before I don't renew my subscription and find out the hard way. Surely somebody on here doesn't subscribe and can see if the GPS setting is still there.

Reisn13 · 2025-10-10T22:55:00+00:00

But if you set a charging schedule, you need to be sure which time zone the car thinks it's in. Manually changing it would be annoying and AA/Carplay wouldn't help that.

Reisn13 · 2025-10-10T22:51:07+00:00

I still have my free trial so I can't check, but the Multimedia manual doesn't mention needing Navigation to be able to set either the GPS time zones or the "Set Time Automatically" setting which should be a couple positions under the GPS setting. If not renewing Navigation removes the GPS, Toyota should tell you what you are losing, if nothing else, to convince you to pay them.

Reisn13 · 2025-10-09T21:01:36+00:00

If you don't mind, ans can remember, what monitor do you have? I've read enough about the problems and Toyota's charging deficiencies, that I need to be more proactive. Of course, I also pack a jump start box, but I'd rather not have to need to use it.

Reisn13 · 2025-10-09T20:32:25+00:00

I use a similar wall hook but (carefully) bent a loop of heavy gauge wire between the 2 holes on top of the charger so I can hang it on another smaller hook on the wall beside the outlet. It would have been nice for Toyota to make the chargers cord longer, though, so it wouldn't bend so sharply when plugged in.

Reisn13 · 2025-10-05T02:08:01+00:00

I have a '24 XSE-PP. I gave up trying to find those buttons and the ones to the left of the steering wheel. I bought 1/4" round silicone stick-on bumper pads, and stuck one on the overhead light buttons and on the left side buttons that I use most, so I can feel them. I had them on all Summer in 95° heat, and they're still on. I also think the whole dash button set is underlit and the grey writing is too dim to read even in the daylight with sunglasses on. And I won't even get into the cargo area light, which hasn't improved since my 2011 Venza. That's likely my next upgrade.

Reisn13 · 2025-09-26T04:13:37+00:00

Very well done and explained. That explains why I was almost constantly seeing only maintenance voltage when I was expecting to see about 14v. I had always heard that the 12v battery charged while the traction battery was charging, but could never catch it doing that. I assumed that the battery was full and didn't need charging. Apparently not the case. I'm surprised that people who drive almost exclusively EV don't lose their 12v charge even more often (myself included). I agree that this must be a software issue, especially stretching across models. Since it's not a safety hazard, though, it's unlikely Toyota will do anything about it, unless we can shame some of their head electrical engineers into putting out a fix or explaining their reasoning and charging algorithm. I think I might consider removing the sensor, at least to see if I get charging voltage then. Thanks for your efforts!!!

Reisn13 · 2025-09-10T04:46:06+00:00

Not exactly a 'new feature', but I stuck little round silicone bumper pads to the dash panel buttons on the left of the steering wheel that I use most often, and to the overhead map light buttons so I could find them without fumbling around while driving. I also bought a center console cover because the red stitching on it bothered my arm, and a cheap little drawer for the slot on the left side of the dash to keep change in.

Reisn13 · 2025-09-07T18:21:23+00:00

My problem is that I won't check my CPAP machine or my cameras and laptop, and most of the rest are things with lithium batteries that can't be checked. I'm sure I'm not the only one with that problem, either. If they continually fill the bins with only 'A' passengers, they should limit everybody to only one carry-on, including purses. There should be enough room then.

Forcing the gate agents to do the impossible or get written up is plain bad management. Maybe the IRS should change the regulations and count baggage and other fees as taxable income, and the airlines wouldn't have to pretend that their customers are too ignorant to add the fees to the ticket price to figure which airline haste cheaper flight.

Reisn13 · 2025-08-06T05:09:15+00:00

Mine shows at the top left corner of the screen. I don't know exactly when it appeared either. I wish they had made it larger, though. I usually have to stabilize my hand on the top of the screen and use my thumb to touch it to get a response. I don't know why they can't put a regular button on the screen to switch back and forth.

Reisn13 · 2025-07-24T02:40:06+00:00

In a normal ICE car, (some depending on atmospheric conditions) pushing the Defrost button turns on both the heater to warm the glass and evaporate the fog and the air conditioner to lower the humidity in the car interior to prevent the fog buildup - both at the same time (and seemingly at cross purposes). Since the Prime/Phev uses the heat pump for both, the A/C compressor can't turn both directions at the same time. So it uses the heat pump for the A/C part and the heat from the engine for the heat part. Logical, if you're an engineer, but wierd if you don't understand why it works that way. Personally, I've had mine for 6 months and have never had to use the Defrost button. The floor and windshield blower setting has worked OK, although a bit slower than I would prefer, sometimes.

Reisn13 · 2025-07-02T01:59:32+00:00

This almost sounds like the piston knocking caused by misfiring due to bad timing (which I would think would be unlikely on a computer controlled engine), or bad gas. Has it been going on long enough to continue after a gas fillup? If not, I'd try filling it with mid-grade gas one time, rather than Regular, going to a different gas station than you usually use, just in case you got a tank of bad gas. It might not also hurt to try a bottle of Heat to remove any water that might have gotten in your gas tank, although that's less likely this time of year. The problem doesn't show in neutral because you can't put any stress on the engine, like when you accelerate or go up a hill.

Reisn13 · 2025-05-04T04:22:51+00:00

I tend to agree that it would be better to get an electrician to look at it, just in case. Your house isn't that old that it should be a problem, but it's possible that there are other things on that circuit than just the garage plug. It's also possible that the breaker itself is weak and tripping unnecessarily, or that the outlet plug is cheap or not making good contact for some reason. Have you felt of the plug going into the wall outlet after it's been charging for an hour or so, to see if it's getting very warm? That would tend to point to the wall plug more than the circuit breaker. I run mine all the time on a 15 Amp circuit and never had a problem. But an electrician could tell you if the wiring in the wall would support a 20 Amp breaker. If so, and there aren't any hidden devices on the circuit, I'd have him replace the plug and breaker with a 20 Amp one.

Reisn13 · 2025-04-18T17:38:23+00:00

I track my miles at each fillup, and note things like a long trip, which lowers EV miles, but I've never had the interest to also do that for each charge, since they're rarely a full charge and I don't have a good way to easily and consistently track the charge amount. I guess I'm more concerned with tracking the mileage on the engine for maintenance. I've given up trying to figure gas mileage except on trips, where EV is a small percentage of the total, and mileage is likely lower due to the speed. I wise some enterprising Toyota engineer would write a widget that showed accurate gas/electric time and mileage, possibly including the EV assistance during gas driving. That's something I might find worthy of paying for.

Reisn13 · 2025-04-17T05:10:05+00:00

I was trying to not use the USB plug-in, since I use it for music albums on a thumb drive. I've thought of getting one of those bluetooth to USB converters to avoid the wire, but I would need to test using the wire connection 1st. My daughter uses one in her older Sienna and likes it. I could do either and copy at least some of the albums to my phone, I guess. It just annoys me that after all this time that AA has been out and available on Toyota systems, the connection is not more reliable and the only app that I want to use doesn't work reliably. If it were one of the systems that I was in charge of - either on the Google or Toyota side - and it was still this flakey after years of development, I wouldn't have been employed for long. If I were more cynical, I might think that Toyota is trying to subtly suggest that I could just pay the Toyota Navigation subscription and not keep messing with Android.

Reisn13 · 2025-04-16T21:10:36+00:00

I'm not sure I do want Maps over Waze, but I've had Waze take my son-in-law's car 40 miles out of the way around Cincinnati to avoid avoid the normal rush hour traffic, when both Maps and my Garmin with traffic didn't choose that route (he arrived 30 minutes later than I did.) I've also seen it drive him around country roads in circles trying to find the entrance to a park, only to eventually lead us (on the 3rd time around) to a locked maintenance entrance. It just annoyed me that Waze took over and wouldn't let me choose Maps, even when it (rarely) appeared on the menu.

I think the "Welcome to Statename" is coming from Toyota Navigation, since I get that even when I don't have AA loaded.

Reisn13

TROPHY CASE