Lexus GS4 - Battery draining

[Pielight]

14 hours ago, Steven Lockey said:

Yeah but what I was saying was the battery was so flat, it wouldn't even have activated the solenoid on a normal car. Literally wouldn't even run any internal lights or the security system e.t.c.

Batteries that hit that level normally experience zero recovery without charging. You need a certain amount of residual charge remaining in the battery in order for there to be sufficient force internally in the battery to move the trapped electrons to the cathode, cos basically all you are doing when resting the battery is giving those trapped electrons time to escape where they are trapped. Without sufficient residual charge, they will never escape. This is one of the main causes of battery degradation, where the crystal build-ups get so thick that the electrons can't escape even at full charge. This is why hitting/shaking a battery can actually cause charge and battery life to be restored as the internal crystal formations can break down when you do this. 

As its an older battery (it the original) its likely mine has a lot of crystalline formations near the cathode and one of those degraded which released sufficient charge to start the car. The formation and break-down of these crystals inside the battery during charge/recharge cycles is one of the main reasons that old batteries not only lose capacity but become a lot more temperamental than new batteries.

Just been doing some reading as well, seems that even if the car doesn't start due to low 12V battery, one of the first things the computer does is open the hybrid battery relays, which charges the high voltage system including the converter, which would then shut off as the 12V failed, but would leave the high voltage system charged and the only outlet for that power to be the 12V battery, so it'd basically give the 12V battery a little bump of power which that charge dissipates from the high voltage system (which can take up to 10 minutes according to the lexus dismantling manual). So its possible that attempting to start the car actually shunted more power into the 12V battery than it took out the battery and that was why it started up normally 10 minutes later. If your 12V battery is truly dead however, that isn't going to help 🙂

So basically there must be enough power in the 12v Battery to operate the relays when you press start. Providing that is the case, then I would expect that when the hybrid system starts, 12v Battery charging begins immediately from the traction Battery even before the engine starts -I imagine that this will be a pretty rapid charge that will enable the engine to be started. As you say, this could not happen when the Battery is too low to activate the ignition system and close the hybrid Battery relays.

There will be some dependency on the hybrid Battery not being near depleted when the car was last parked up, ie if ev mode was used prior to parking the hybrid Battery may not be able to run the Battery charging system long enough to get the engine started. At least you have a better chance than a non hybrid car of getting going when 12v Battery is low.

[NemesisUK]

30 minutes ago, Pielight said:

So basically there must be enough power in the 12v battery to operate the relays when you press start. Providing that is the case, then I would expect that when the hybrid system starts, 12v battery charging begins immediately from the traction battery even before the engine starts -I imagine that this will be a pretty rapid charge that will enable the engine to be started. As you say, this could not happen when the battery is too low to activate the ignition system and close the hybrid battery relays.

There will be some dependency on the hybrid battery not being near depleted when the car was last parked up, ie if ev mode was used prior to parking the hybrid battery may not be able to run the battery charging system long enough to get the engine started. At least you have a better chance than a non hybrid car of getting going when 12v battery is low.

In the hybrid car there is no starter motor the engine is spun up by one of the electric motors, powered by the traction Battery.

The 12v Battery simply operates the entry system and boots up the computers. Once in the Ready state all electrics are powered by the traction Battery. The traction Battery will never be depleted too low to start the engine in normal use i.e. after a run the Battery will have the required charge.

[wharfhouse]

40 minutes ago, Pielight said:

So basically there must be enough power in the 12v battery to operate the relays when you press start. Providing that is the case, then I would expect that when the hybrid system starts, 12v battery charging begins immediately from the traction battery even before the engine starts -I imagine that this will be a pretty rapid charge that will enable the engine to be started. As you say, this could not happen when the battery is too low to activate the ignition system and close the hybrid battery relays.

There will be some dependency on the hybrid battery not being near depleted when the car was last parked up, ie if ev mode was used prior to parking the hybrid battery may not be able to run the battery charging system long enough to get the engine started. At least you have a better chance than a non hybrid car of getting going when 12v battery is low.

My understanding is that even if the hybrid Battery says it is empty on the car display it still has at least 20% charge and probably before that the ICE would have kicked in so it's virtually impossible to discharge the traction Battery to a point it can't start the ICE (as above it's the traction Battery that uses one of the electric motors to start the ICE and not the 12V battery). 

[Pielight]

18 minutes ago, NemesisUK said:

In the hybrid car there is no starter motor the engine is spun up by one of the electric motors, powered by the traction battery.

The 12v battery simply operates the entry system and boots up the computers. Once in the Ready state all electrics are powered by the traction battery. The traction battery will never be depleted too low to start the engine in normal use i.e. after a run the battery will have the required charge.

I agree in normal use, but was referring to where the 12v Battery is flat….as the OP was unable to get the car started until time was allowed for the Battery to be charged by the hybrid system might suggest that a minimum voltage (above that required to start the charging process) is required to close the engine start relays. Too low voltage can damage certain electrical equipment and low voltage relays can protect against that (trains have had LVRs for many years to protect against this). Just speculating, but something seems to have prevented the engine starting in the first place.

incidentally, old diesel electric locos I’ve driven built in the 50s and early 60s never had starter motors and worked on a similar principle to hybrid cars, but without storage batteries. Much of the technology has been around for a long time.

[NemesisUK]

If the 12v Battery was flat how was the car unlocked? How was the car 'woken up' and into which state?

[Pielight]

2 minutes ago, NemesisUK said:

If the 12v battery was flat how was the car unlocked? How was the car 'woken up' and into which state?

A flat Battery can often power the low amp/current equipment but not higher power stuff. Otherwise, if you could unlock any car you would always be able to start it and of course that often is not the case.

[Herbie]

16 hours ago, Steven Lockey said:

Just been doing some reading as well, seems that even if the car doesn't start due to low 12V battery, one of the first things the computer does is open the hybrid battery relays, which charges the high voltage system including the converter, which would then shut off as the 12V failed, but would leave the high voltage system charged and the only outlet for that power to be the 12V battery, so it'd basically give the 12V battery a little bump of power which that charge dissipates from the high voltage system (which can take up to 10 minutes according to the lexus dismantling manual). So its possible that attempting to start the car actually shunted more power into the 12V battery than it took out the battery and that was why it started up normally 10 minutes later. If your 12V battery is truly dead however, that isn't going to help

I'm sorry Steven but again, this just doesn't happen and in fact, it can't happen.

The high voltage power cables leading from the traction Battery are controlled by 12V NO (Normally Open) relays. As soon as the car is shut off these relays open and stop any output from the traction Battery, therefore it can't give "a little bump of power" to anything, let alone the 12V Battery.

There's really only two states - either there's enough power in the 12V Battery to boot the computers and get the car into READY mode, or there isn't. And if there isn't, then there's just no way for the hybrid system to 'assist' the 12V Battery.

[Herbie]

2 hours ago, Pielight said:

So basically there must be enough power in the 12v battery to operate the relays when you press start. Providing that is the case, then I would expect that when the hybrid system starts, 12v battery charging begins immediately from the traction battery even before the engine starts -I imagine that this will be a pretty rapid charge that will enable the engine to be started

Mostly correct Paul.

When a hybrid car is in READY mode it's just the equivalent of a conventional car sat idling, with the engine running and the alternator spinning, so yes, the 12V Battery will be receiving charge at this point, but it's not the 12V Battery that starts the engine.

When the hybrid system wants to run the engine it energises MG1 and uses that to spin the engine up to 1,000rpm before applying fuel and a spark to fire it.

[Pielight]

That all makes sense to me Herbie and more or less how I imagined it might function. I presumed that the relay (which I now know is MG1) is powered by the 12v Battery which connects the traction Battery to the traction motor when activated. I would imagine that MG1 needs a minimum voltage to operate which might explain why a partially discharged 12v Battery may need a little time to charge (via traction battery) before MG1 is activated? Pure guess, though it might explain one of the posts where car wouldn't get underway after lights left on BUT as you say this could only happen with ready mode/ignition circuit activated - could there be a state where the ignition system and Battery charge can be activated but not be ready to enable driving until there is sufficient 12v supply voltage to energise MG1? Not critical knowledge but all Interesting stuff!😅

[Steven Lockey]

3 hours ago, Herbie said:

I'm sorry Steven but again, this just doesn't happen and in fact, it can't happen.

The high voltage power cables leading from the traction battery are controlled by 12V NO (Normally Open) relays. As soon as the car is shut off these relays open and stop any output from the traction battery, therefore it can't give "a little bump of power" to anything, let alone the 12V battery.

There's really only two states - either there's enough power in the 12V battery to boot the computers and get the car into READY mode, or there isn't. And if there isn't, then there's just no way for the hybrid system to 'assist' the 12V battery.

 

6 hours ago, Pielight said:

So basically there must be enough power in the 12v battery to operate the relays when you press start. Providing that is the case, then I would expect that when the hybrid system starts, 12v battery charging begins immediately from the traction battery even before the engine starts -I imagine that this will be a pretty rapid charge that will enable the engine to be started. As you say, this could not happen when the battery is too low to activate the ignition system and close the hybrid battery relays.

There will be some dependency on the hybrid battery not being near depleted when the car was last parked up, ie if ev mode was used prior to parking the hybrid battery may not be able to run the battery charging system long enough to get the engine started. At least you have a better chance than a non hybrid car of getting going when 12v battery is low.

Sorry but that doesn't make sense. The laws of physics basically prevent this from been true 🙂

When I pressed the brake + power, the light came on and I hit the power button. Car light up, dashboard e.t.c. but very dim then everything went out.
So clearly it had got to the stage of booting up the computer or the dash wouldn't have illuminated as that is controlled by the computer.

Tried it several times and the exact same thing happened. It didn't get worse (aka dying sooner) or last any longer. Assuming the 12V was basically nearly fully discharged, you'd expect it to get worse with each attempt if there was no external power source involved. 

Its possible the 12V had just enough power to open the relays, causing the power to cut off to the computer after the relays had opened but before the 12V starts receiving charge, or some other process pushed the power-drain over the edge directly after opening the relays. That would leave a charge in the high power circuits which is directly connected to the converter and via that to the 12V Battery according to the Lexus service wiring diagrams.

Traction Battery was basically full when I pulled up but was a bar lower when the car actually started according to the dash display.

"There's really only two states - either there's enough power in the 12V Battery to boot the computers and get the car into READY mode, or there isn't. And if there isn't, then there's just no way for the hybrid system to 'assist' the 12V Battery."
This statement can't be true as the car has to open the relays early in this process, so the traction Battery is connected to the system before the car is in READY mode. Since the laws of causality prevent time-reversal, the traction Battery MUST be connected to the system before the car is in ready mode, since other steps like starting the engine, bringing oil to pressure e.t.c. also need to happen before the car is in READY mode and rely on the traction Battery been connected.  Given capacitors are one of the biggest delays in electronics and boost converters use some big capacitors, this does leave a fair sized gap while the capacitors are charging that the 12V could cut out, causing the car to shut down but it hasn't got to READY but has charged the high voltage circuits (at least partially). The age of my car is likely an issue as I believe capacitors take longer to charge as they get older leaving a even longer time the car is relying on the 12V Battery maintaining charge.

Don't forget, stuff like this doesn't happen instantly. Just because the relays are open, doesn't mean power instantly starts flowing from the traction batteries to everywhere else. Capacitors take time to charge, transformers add a delay e.t.c. So even after the relays are open, the 12V is not instantly receiving charge from the traction Battery. That leaves an interval in which the 12V can cut out but the high voltage circuits are now charged. The relays automatically close when the 12V Battery cuts out but that doesn't instantly remove the charge from the high voltage circuit. Its like a gas canister you fill with high pressure gas, when you take the pump away and seal the top, the gas inside is still under-pressure till it can leak out and establish a equilibrium with the outside pressure. 

Same thing would happen in the high voltage system, where the power basically leaks out over up to ten minutes after the system is charged from the traction Battery. Lexus specifically state not to touch any of the high voltage system till ten minutes after the car has been disabled as it can take that long for the high voltage system to fully discharge. One of the main places this power would 'leak' to is the 12V Battery via the converter.

If the Battery was completely flat and couldn't open the relays, this wouldn't happen yeah, car would just stay dead.

It may be this situation is a edge-case that only happens when the Battery has a very specific amount of power, but unless the Lexus wiring diagrams are wrong, it definitely CAN happen, however unlikely it is. 

tl;dr;
Power button pressed
Computer boots
Relays opened
*Other processes to get car ready*
12V starts receiving charge from Traction Battery
Final processes to get car ready
Car now in READY mode

If the 12V cuts out in *Other processes to get car ready* stage, it would cause the car to cut out with the high-voltage system charged, which would
then dissipate that charge into the 12V Battery via the converter.

[Pielight]

1 hour ago, Steven Lockey said:

 

Sorry but that doesn't make sense. The laws of physics basically prevent this from been true 🙂

When I pressed the brake + power, the light came on and I hit the power button. Car light up, dashboard e.t.c. but very dim then everything went out.
So clearly it had got to the stage of booting up the computer or the dash wouldn't have illuminated as that is controlled by the computer.

Tried it several times and the exact same thing happened. It didn't get worse (aka dying sooner) or last any longer. Assuming the 12V was basically nearly fully discharged, you'd expect it to get worse with each attempt if there was no external power source involved. 

Its possible the 12V had just enough power to open the relays, causing the power to cut off to the computer after the relays had opened but before the 12V starts receiving charge, or some other process pushed the power-drain over the edge directly after opening the relays. That would leave a charge in the high power circuits which is directly connected to the converter and via that to the 12V battery according to the Lexus service wiring diagrams.

Traction battery was basically full when I pulled up but was a bar lower when the car actually started according to the dash display.

"There's really only two states - either there's enough power in the 12V battery to boot the computers and get the car into READY mode, or there isn't. And if there isn't, then there's just no way for the hybrid system to 'assist' the 12V battery."
This statement can't be true as the car has to open the relays early in this process, so the traction battery is connected to the system before the car is in READY mode. Since the laws of causality prevent time-reversal, the traction battery MUST be connected to the system before the car is in ready mode, since other steps like starting the engine, bringing oil to pressure e.t.c. also need to happen before the car is in READY mode and rely on the traction battery been connected.  Given capacitors are one of the biggest delays in electronics and boost converters use some big capacitors, this does leave a fair sized gap while the capacitors are charging that the 12V could cut out, causing the car to shut down but it hasn't got to READY but has charged the high voltage circuits (at least partially). The age of my car is likely an issue as I believe capacitors take longer to charge as they get older leaving a even longer time the car is relying on the 12V battery maintaining charge.

Don't forget, stuff like this doesn't happen instantly. Just because the relays are open, doesn't mean power instantly starts flowing from the traction batteries to everywhere else. Capacitors take time to charge, transformers add a delay e.t.c. So even after the relays are open, the 12V is not instantly receiving charge from the traction battery. That leaves an interval in which the 12V can cut out but the high voltage circuits are now charged. The relays automatically close when the 12V battery cuts out but that doesn't instantly remove the charge from the high voltage circuit. Its like a gas canister you fill with high pressure gas, when you take the pump away and seal the top, the gas inside is still under-pressure till it can leak out and establish a equilibrium with the outside pressure. 

Same thing would happen in the high voltage system, where the power basically leaks out over up to ten minutes after the system is charged from the traction battery. Lexus specifically state not to touch any of the high voltage system till ten minutes after the car has been disabled as it can take that long for the high voltage system to fully discharge. One of the main places this power would 'leak' to is the 12V battery via the converter.

If the battery was completely flat and couldn't open the relays, this wouldn't happen yeah, car would just stay dead.

It may be this situation is a edge-case that only happens when the battery has a very specific amount of power, but unless the Lexus wiring diagrams are wrong, it definitely CAN happen, however unlikely it is. 

tl;dr;
Power button pressed
Computer boots
Relays opened
*Other processes to get car ready*
12V starts receiving charge from Traction battery
Final processes to get car ready
Car now in READY mode

If the 12V cuts out in *Other processes to get car ready* stage, it would cause the car to cut out with the high-voltage system charged, which would
then dissipate that charge into the 12V battery via the converter.

I couldn't make sense of what didn't make sense!!😅

[Steven Lockey]

You guys saying this can't happen 🙂
There must be a delay between the relays opening and current actually flowing through to the 12V circuit from the traction Battery via the converter, simply because of physics, so if the 12V gives out during this time either due to additional charge been pulled or it just running out of charge, then you've got the circumstance I described above.

Cos basically if the 12V circuit loses power for even a split second, the computer will disengage which should automatically close the relays again and the car turns fully off. The 300v circuit is still charged however and has a bit of power now stored in it and the only 'exit' for the power in this circuit is via the converter to the 12v Battery. This will gradually leak out over approx 10 minutes according to Lexus.

The component delay is called the 'tau' in electronics, I'm not sure what the tau is of the converter in the gs450h, but I can't see that the tau of the converter would of been a major consideration during the design process so is likely towards the high end. I know some extreme examples can have a tau measured in minutes. I'd expect it to be sub 1 second for a component like this but it could still be big enough to cause this to happen. How big that 'window' is would depend on the size of the tau of the converter which would affect how likely this was to have happened.

I'm not saying this DID happen or that its at all likely to happen, but from the order in which the operations must happen to start up the car, its 100% possible that it could happen.

[steve2006]

On 10/26/2021 at 7:50 AM, Shabby said:

I agree with the previous replies plus I'd have the alternator checked to see that it's charging the battery properly.

Lexus hybrids don’t have a conventional engine driven alternator the 12v Battery charge comes from the hybrid power unit.

[wharfhouse]

6 hours ago, Steven Lockey said:

When I pressed the brake + power, the light came on and I hit the power button. Car light up, dashboard e.t.c. but very dim then everything went out.
So clearly it had got to the stage of booting up the computer or the dash wouldn't have illuminated as that is controlled by the computer.

Tried it several times and the exact same thing happened. It didn't get worse (aka dying sooner) or last any longer. Assuming the 12V was basically nearly fully discharged, you'd expect it to get worse with each attempt if there was no external power source involved. 

IMHO I think you are over-thinking the technology. You said you left the lights on which had largely drained the Battery when you got back to the car but there was still enough power to open the car and as you say light the dashboard but dimly and then it all went out and the 12V Battery could not get the car into Ready mode. Being able to do this a few times makes sense as every time the Battery needs to deliver a bit more than it has left when it tries to finally get into Ready mode it does the same thing. Seems like a pretty typical nearly flat Battery response and you would have eventually not even have been able to get the lights on the dash if you had continued longer. As I said in an earlier reply, I had the exact same thing happen in a normal ICE car (not hybrid) - I had left the headlights on and when I got back I could open the car and dashboard lights came on but couldn't start the car. However, after turning off the offending lights and left the car standing for around 20 minutes I was able to just crank over the engine enough to get it to start. If a 12V Battery can recover enough to crank an ICE I'm sure that in a hybrid it can recover enough to boot the computers fully and get to Ready mode as that requires significantly less power. I have spoken to others with ICE cars (not hybrid) and they have experienced similar to myself, if the Battery has flattened for something like leaving lights on, turn everything off and leave it for a while and there is a chance the Battery will recover enough to crank the engine and start it. The time this likely won't work is if left for a long time (like days/weeks) and/or it is a small parasitic drain that has totally flattened the Battery and for example the central locking isn't working and no lights at all on the dash. Personally I carry one of the glovebox jump start Battery packs just in case - not had to use it on my car yet though I did use it once to help a van driver (not hybrid but a diesel) with a flat Battery (as couldn't give him a jump start from my hybrid) and as it started his van I'm confident it will start my hybrid.

[Herbie]

30 minutes ago, wharfhouse said:

IMHO I think you are over-thinking the technology.

That is exactly what I was going to say to Steven.

Absolutely everything is controlled by the hybrid system so if the 12V Battery cannot get that into READY mode then it's dead.

There's no question of the hybrid system being able to do anything before it achieves READY status and, as I said somewhere above, it takes less than 20A to do that instead of the 300A or more a conventional car would need.

[Pielight]

Summed up in a nutshell to my mind, ie if you don’t get dash lights/ready you’re going nowhere.

[Pielight]

1 hour ago, wharfhouse said:

IMHO I think you are over-thinking the technology. You said you left the lights on which had largely drained the battery when you got back to the car but there was still enough power to open the car and as you say light the dashboard but dimly and then it all went out and the 12V battery could not get the car into Ready mode. Being able to do this a few times makes sense as every time the battery needs to deliver a bit more than it has left when it tries to finally get into Ready mode it does the same thing. Seems like a pretty typical nearly flat battery response and you would have eventually not even have been able to get the lights on the dash if you had continued longer. As I said in an earlier reply, I had the exact same thing happen in a normal ICE car (not hybrid) - I had left the headlights on and when I got back I could open the car and dashboard lights came on but couldn't start the car. However, after turning off the offending lights and left the car standing for around 20 minutes I was able to just crank over the engine enough to get it to start. If a 12V battery can recover enough to crank an ICE I'm sure that in a hybrid it can recover enough to boot the computers fully and get to Ready mode as that requires significantly less power. I have spoken to others with ICE cars (not hybrid) and they have experienced similar to myself, if the battery has flattened for something like leaving lights on, turn everything off and leave it for a while and there is a chance the battery will recover enough to crank the engine and start it. The time this likely won't work is if left for a long time (like days/weeks) and/or it is a small parasitic drain that has totally flattened the battery and for example the central locking isn't working and no lights at all on the dash. Personally I carry one of the glovebox jump start battery packs just in case - not had to use it on my car yet though I did use it once to help a van driver (not hybrid but a diesel) with a flat battery (as couldn't give him a jump start from my hybrid) and as it started his van I'm confident it will start my hybrid.

Ive had same experiences. I’ve on many occasions over the years, left a car or motorbike on which the Battery is no longer able to crank the engine, to stand for a while and gone back and the Battery has a new lease of life for further attempts.

[Steven Lockey]

Yeah as I said I'm not saying this DID happen, but its certainly possible it could happen, but would require the 12V Battery to cut out at the exact period between the relays opening and the converter providing 12V to the computer to take over from the Battery. Its probably pretty unlikely to actually happen in real life. The tau of a converter like this is probably sub 0.1s so its a pretty fine gap for the Battery to die in. Might be higher if its designed to power the 800v circuit before the 12V circuit however but I've not dug that far into it.

I'd completely agree its far more likely the Battery just recovered enough after a short rest.

I'm a programmer so I'm used to digging through documentation and trying to work out all possibilities, cos if I don't, well we call those bugs (or features lol) and no-one likes a bug.

[LenT]

Coming across this thread rather reinforced my decision to avoid the added complexity of a hybrid when I bought my Lexus.  It’s an added complication too far for me, I suspect.

For example, the problems created by the apparently straightforward case of a flat Battery.  If I have a degree of flatness with which my trusty C-Tech trickle charger cannot cope, I have a Plan B.

A NOCO Battery power pack.  This, it is claimed, will store sufficient power for 12 months to start the average car several times.  I haven’t yet had cause to use it, but a similar power pack was used by an AA patrol to start my wife’s car after the Battery was drained by someone leaving the lights on all night!

(Oh alright…it was me!)

Anyway, I was impressed at how effortlessly the car started, so I got one myself.  Now whether there’s some reason why power packs won’t work on a hybrid, I have no idea.  But if that’s not a problem, then I think that having read this thread I’d been inclined to invest in one.

[royoftherovers]

16 minutes ago, LenT said:

Coming across this thread rather reinforced my decision to avoid the added complexity of a hybrid when I bought my Lexus.  It’s an added complication too far for me, I suspect.

For example, the problems created by the apparently straightforward case of a flat battery.  If I have a degree of flatness with which my trusty C-Tech trickle charger cannot cope, I have a Plan B.

A NOCO battery power pack.  This, it is claimed, will store sufficient power for 12 months to start the average car several times.  I haven’t yet had cause to use it, but a similar power pack was used by an AA patrol to start my wife’s car after the battery was drained by someone leaving the lights on all night!

(Oh alright…it was me!)

Anyway, I was impressed at how effortlessly the car started, so I got one myself.  Now whether there’s some reason why power packs won’t work on a hybrid, I have no idea.  But if that’s not a problem, then I think that having read this thread I’d been inclined to invest in one.

You are selling yourself short old pal.

Hybrids and you are a perfect match.

Trust the Toyota technology.

I have a Plan B too and have used it several times. No more calls to AA or the need for Jump Leads.

 

ps, I thought that the new Brian Cox Documentary last Wednesday on the UNIVERSE was dreadful and was surprised that he allowed his subject to be so and unnecessarily dramatic. His oral contribution was outweighed more that 10 fold by the use of DR WHO type presentations.

 

[Duggie B]

38 minutes ago, LenT said:

Now whether there’s some reason why power packs won’t work on a hybrid, I have no idea.

Noco power pack works fine I've used one myself a couple of times nice to have a safety net in the glove box 

[Herbie]

39 minutes ago, LenT said:

Now whether there’s some reason why power packs won’t work on a hybrid, I have no idea.

Absolutely no reason whatsoever - it's just a 12V source like any other 12V source.

[LenT]

2 hours ago, royoftherovers said:

You are selling yourself short old pal.

Hybrids and you are a perfect match.

Trust the Toyota technology.

I have a Plan B too and have used it several times. No more calls to AA or the need for Jump Leads.

 

You’re too kind, John.  However car electrics has never been a strong point with me.  😒

And once I discovered that injudicious prodding about could deliver a potentially fatal voltage, I felt I didn’t need to know much more!

2 hours ago, royoftherovers said:

ps, I thought that the new Brian Cox Documentary last Wednesday on the UNIVERSE was dreadful and was surprised that he allowed his subject to be so and unnecessarily dramatic. His oral contribution was outweighed more that 10 fold by the use of DR WHO type presentations.

 

Cox-wise, I’m recording the series and haven’t yet had a chance to view it, but clearly I must now.  And now I fear the worst!

Of course, the real culprits may be the production team and I suspect that even the likes of Brian Cox have limited influence in that respect.  I think this is because most people on the production side have an arts background rather than a science one.  The other side of the coin is that comparatively few scientists are very good communicators!

Sadly, the result is that if you know anything about the subject, it is irredeemably dumbed down.  But hopefully if you know nothing, it may just spark an interest  

Apropos nothing at all, my brother-in-law has an actual degree in physics and is very dismissive of Brian Cox…

[Pielight]

5 hours ago, LenT said:

Coming across this thread rather reinforced my decision to avoid the added complexity of a hybrid when I bought my Lexus.  It’s an added complication too far for me, I suspect.

For example, the problems created by the apparently straightforward case of a flat battery.  If I have a degree of flatness with which my trusty C-Tech trickle charger cannot cope, I have a Plan B.

A NOCO battery power pack.  This, it is claimed, will store sufficient power for 12 months to start the average car several times.  I haven’t yet had cause to use it, but a similar power pack was used by an AA patrol to start my wife’s car after the battery was drained by someone leaving the lights on all night!

(Oh alright…it was me!)

Anyway, I was impressed at how effortlessly the car started, so I got one myself.  Now whether there’s some reason why power packs won’t work on a hybrid, I have no idea.  But if that’s not a problem, then I think that having read this thread I’d been inclined to invest in one.

If anything, a hybrid will considerably improve your chances of getting going with a flattish 12v Battery. Unlike a conventional car which has to have sufficient power in its Battery to turn over an engine agains the drag of cylinder compression, the 12v Battery on a hybrid only needs enough current to energise the relevant relay/s to connect the hybrid Battery to the electric motor which cranks the engine for starting. The hybrid Battery itself is much longer lasting than a regular 12v Battery (hence extremely long warranty compared with a regular battery).

Recent surveys and studies have shown hybrid petrol cars to be the most reliable on the road - try Googling this to check it out.

 

[LenT]

12 hours ago, royoftherovers said:

ps, I thought that the new Brian Cox Documentary last Wednesday on the UNIVERSE was dreadful and was surprised that he allowed his subject to be so and unnecessarily dramatic. His oral contribution was outweighed more that 10 fold by the use of DR WHO type presentations.

Sadly, John, I have to agree.  I think it must be a generational thing.  It’s a fad that plagues so much of current TV documentaries and dramas.

But perhaps the rock concert accompaniment was to remind us that he once had a proper job before doing astrophysics!

I also noted that the BBC effects department once again laid to rest the myth that sound doesn’t carry in space!

Still, I can understand why it didn’t tackle the more fundamental questions about the origin of the Universe, although that may happen in later episodes. And I thought it perked up when he discovered photosynthesis and dwarf stars - although shouldn’t they now be ‘stars of restricted growth’?

As an experiment, halfway through I turned off the sound and switched on the subtitles.  That enabled me to concentrate on the script, revealing that the programme could probably have been 20 minutes shorter, and that innocent amusement can be derived from the odd typo.

Finally, I was relieved to discover that if I hadn’t already had enough of the sound track, I could get a personal copy.

Fortunately, I have had Fairport Convention’s ‘Unhalfbricking’ album, with Sandy Denny’s ‘Who knows where the time goes’, since it was released in 1969, so I can pass on that.

And now back to more Earthly matters….