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On 3/29/2020 at 8:15 PM, Thackeray said:

On the IS I have the impression that in Normal mode the accelerator is disabled in Park whether you have your foot on the brake or not. That's to say, you can't rev the engine while the car is stationary in Park. But just a couple of days ago I discovered that you can rev the engine in Park when you select Sport mode.

It turns out I was wrong. Further investigation shows that on the IS you can rev the engine while in Park and in any mode (Eco, Normal, Sport). The accelerator pedal is misleading because it doesn't react as a conventional car would when you begin to press it. So although a fairly light touch will get the car moving in Drive, nothing happens for the same amount of pressure when you're in Park. But when you press it a bit further the engine will rev. I don't know if there's a limit to how fast you can rev the engine; I didn't press it very far.

But I noticed something else that's interesting. With the car in Park and without touching the accelerator, the graphic displays show that the engine is charging the hybrid Battery. But if you rev the engine, it stops charging the hybrid Battery, according to the graphic displays. If this accurately represents what is going on, I imagine Motor Generator 1 (MG1) is allowed to spin freely without any load because with the car and MG2 stationary, it could damage MG1 if it was spinning faster than its generating capacity allowed. Or maybe there's some other reason. Either way, it looks as though on the IS the generation stops when you rev the engine and the car is in Park..

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On 4/1/2020 at 12:29 AM, mick164 said:

Hi all..

This is sort of an observation and a question.. my GS450h has been parked up for nearly 2 weeks now, and the keyless entry has become erratic.  I can't open or start the car first thing in the morning, then 20 minutes later it's fine.

I measured the 12v battery at 12.35v after sitting all night.. is this low enough to mess with the keyless entry?

Thanks 🙂

 

Thanks voltage is fine, most likely to do with your fob Battery.

 

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  • 2 weeks later...

Just went to get the IS 300h out of the garage to take for a quick charge up drive. That was my intention anyway, Battery was as flat as a pancake.

Tried to charge Battery but being a gel Battery and my charger not being intelligent, it didn't want to know.  I had another Battery in the garage and managed

to start it with a jump.  Although I am now told that wasn't a wise thing to do.... I will be getting a smart charger, and hope I haven't damaged the gel Battery.

 

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55 minutes ago, Hadrian said:

and managed

to start it with a jump.  Although I am now told that wasn't a wise thing to do....

Who told you that?

There's nothing wrong with jump starting a hybrid as all you're doing is supplementing a dodgy 12V source by piggybacking a good 12V source on to it.

12V is 12V, it doesn't matter to the car where it comes from (although I wouldn't try to use a Battery charger as a jump source).

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1 hour ago, Hadrian said:

Just went to get the IS 300h out of the garage to take for a quick charge up drive. That was my intention anyway, battery was as flat as a pancake.

Tried to charge battery but being a gel battery and my charger not being intelligent, it didn't want to know.  I had another battery in the garage and managed

to start it with a jump.  Although I am now told that wasn't a wise thing to do.... I will be getting a smart charger, and hope I haven't damaged the gel battery.

 

It isn't a gel Battery it is an AGM Battery. A normal charger is ok to get them at least 80% charged. Do you have a volt meter to test the voltage.

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The Battery is only showing 3.6v

I started it earlier, drove up to the end of my road and back, but tried it later and it was still flat.

I'm a bit worried about going on a longer drive, in case when I stop at a junction and the engine cuts, it wont start again.

A normal charger comes up with "Error", so I bought a smart charger and that keeps cutting out after a couple of minutes.

 

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8 minutes ago, 200h said:

once foot on the brake and the start button has been pressed

your hybrid battery takes over and runs the car so dont worry.

Yes, but if the car did 'stall' for want of a better word, with his 12V Battery being down to 3.6V he's right, it wouldn't reboot the hybrid system and he'd be stuck.

@Hadrian at 3.6V I would be thinking it's gone to Battery heaven. You could try getting the car into READY (with radio off, aircon off etc., etc.,) and just leave it for 60 minutes in READY and Park. It may r may not help but at least it would still be on your driveway instead of anywhere else.

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Thanks for advice chaps.

I started it again (jumping from another battery) and held my foot on the loud pedal for a few minutes.

While the engine was running I checked the voltage and it was about 14v, so alternator OK.

I reconnected the charger and that is working OK now there's some volts in the Battery, reading around 11.7v

I will leave that on for a while and do some checks during the week.  Fingers crossed that I don't need a new Battery

as I don't expect they come cheap.

What is the life expectancy of a Battery ?,  depends on usage I imagine ?

 

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11 minutes ago, Hadrian said:

I started it again (jumping from another battery) and held my foot on the loud pedal for a few minutes.

Glad to hear you've got it working. This reminds me that there are a couple of things I don't understand in this area which maybe the forum experts can answer.

First, I tried revving the engine while in Park the other day and I noticed that the graphic display showed that the engine was charging the hybrid Battery while idling but it stopped charging when I revved the engine. Does anyone know if this is a correct display of what is happening? Does the charging stop when you rev the engine? Might this be because MG1 (which does the job of an alternator) would be spinning too fast in this situation?

I wondered if this could be right and I went back to my main reference point for understanding the transmission - this now fairly old but very useful page showing a graphic of how it works.

If you scroll down to near the bottom of the page you'll see the working graphic of the power split device (You may have to permit Adobe flash to run to see this.)

I deduced from this that on the early Prius that it represents, when stationary in Park with the engine idling around 1,100 rpm, motor/generator 1 (MG1) is turning at around 4,000 rpm.

On the IS300h it's possible to cruise at 70mph with the engine turning at around 1,250 rpm - not much faster than its idling speed of 1,100 rpm. The IS300h is different, of course, but on the Prius graphic demo, if you set the speed to 70mph and the engine to around 1,300 rpm, MG1 is now spinning at around 6,000 rpm - but in the opposite direction!

Now, I assume that it can generate electricity spinning in either direction. If that's the case and you want to charge the 12v Battery, it might seem there's not a huge advantage to be got from driving at 70mph as compared to leaving the engine idling at 1,100 rpm.

There's also the issue that when the car is stationary, I assume all the torque from the engine is driving MG1. By contrast, in the early Prius torque was split through the Power Split Device by 28% to MG1 and 72% to the road wheels. So maybe it's the case that when you're cruising at 70 mph only around a third of the torque is driving MG1,  compared to 100% when you're stationary.

Can some expert confirm if this is right or not and point out where I've misunderstood what's going on? If the above is right, it seems to suggest that to charge the 12v Battery, it may be more effective to keep the car stationary rather than cruising down a motorway.

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30 minutes ago, Hadrian said:

Also, (although this may have been answered already ?) Can the hybrid battery degrade if not used regularly ?

It is just a lot of Nickel Metal Hydride Battery cells all placed into a Battery pack. They don't have memory effort and they degrade by being cycled (used) - they are fine not being used provided there is sufficient charge. The cells will however slowly discharge so you need to allow your vehicle to charge the hybrid Battery maybe once every month or two - just put it in Ready for an hour which will also charge your aux Battery (but that needs to be done more regularly)

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I have a GS300h and am completely 'confined to barracks' as a result of being categorised as 'extremely vulnerable' to the current virus.

 My  car  is covered and the 12v Battery is attached to a smart charger. I am concerned to know if this is sufficient to preserve the health of the lithium Battery. Unfortunately, I have been unable to find a simple yes/no answer in the forum comments. perhaps there is no such simple answer, but I'd be grateful for any advice.

Many thanks

Tony

 

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12 hours ago, tonda1 said:

I have a GS300h and am completely 'confined to barracks' as a result of being categorised as 'extremely vulnerable' to the current virus.

 My  car  is covered and the 12v battery is attached to a smart charger. I am concerned to know if this is sufficient to preserve the health of the lithium battery. Unfortunately, I have been unable to find a simple yes/no answer in the forum comments. perhaps there is no such simple answer, but I'd be grateful for any advice.

Many thanks

Tony

 

Welcome Tony. You normally don't have to worry about the hybrid Battery but probably best to put the vehicle into Ready mode for 30 mins every six to eight weeks to allow the Battery to be charged up a little as there will be some self-discharge. Just let the engine cut in and out as required.

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I don't wish to be pedantic but just for the record Lexus (and Toyota hybrids in general) don't use Lithium batteries - they have NiMH (Nickel Metal Hydride) batteries. That technology is a bit dated now, but Toyota made it work well and they've stuck with it.

NiMH cells have an alkaline electrolyte, usually potassium hydroxide. The positive electrode is nickel hydroxide, and the negative electrode is hydrogen in the form of an interstitial metal hydride.

But Lexus have switched to Lithium Ion batteries for the new Lexus UX 300e - the first all-electric one.

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1 hour ago, johnatg said:

I don't wish to be pedantic but just for the record Lexus (and Toyota hybrids in general) don't use Lithium batteries

To be really pedantic, very few Toyota hybrids use Lithium but they are used in the standard Prius+ and also the plug-ins.

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  • 2 weeks later...

Hi all, would appreciate a bit of newb advice here. I own a 4th gen gs450h (12 plate) that has been unused for around 3-4 weeks due to the lockdown. 

I tried to start it yesterday but had a problem with the Battery. To begin with the alarm went off when I opened the drivers door using the keyless entry even though the central locking did unlock. 

The alarm stopped once I turned the car on using the start/stop button with my foot on the brake. The dashboard lights also came on but the car didn't start ie the READY light didn't come on. It also said unable to disengage parking brake (or words to that effect). 

As above, I presume its due to a depleted 12v Battery. Would you agree?

If so, what would you say is the best course of action? I don't own a Battery charger so will need to buy one. I don't have access to a socket near the car so it would need to be portable. Anything I should aim for or avoid when it comes to buying one? 

Alternatively I could ask my neighbour to jump start and then I go on a drive but would like to avoid if possible (I don't own jump leads). 

Thanks in advance. 

 

Edit: I appreciate there are some tips earlier here about keeping a Battery charged during lockdown but wasn't sure if a.) the Battery was definitely the issue and b.) the recommended way to remedy it. Thanks 

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it is the 12v Battery in the car

with not knowing how long this crisis will go on for

i would go to euro carparts website and order a 12v Battery

and a set of jump leads & charger

just buy the cheapest they have for all 3 items and use this Battery for

jump starting (technically you arent jump starting just powering the computers)

i bought a 2nd 12v Battery after my Battery went flat over a 3 week

period in winter of inactivity, its just nice to know you have a 2nd source to help you out.

 

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