Solar Charger

[bearwood]

Hello all

In the past I have used a solar trickle charger to maintain a CT 200h at work that was used only occasionally as a pool car, and it worked well being connected via the diagnostic port. Now retired I'm looking for one myself but they all seem to offer either croc clips or 12v socket connector. Is it ok to charge via the 12v connector on a 300h so as to avoid wires running outside the car to the bonnet when using crocodile clips?

 

Thanks

Peter

 

[Herbie]

This one has an OBD2 connector but is currently unavailable at Amazon

You may find one on eBay though.

Not sure about the IS but on the RX the 12V power socket/cig lighter is only active when the ignition s on, so no good for this.

[bearwood]

Thanks for the reply Herbs, than is actually  the one I used to use, so I did order one four weeks ago on amazon, but it never arrived, getting it refunded.

Regards

Peter

[royoftherovers]

48 minutes ago, bearwood said:

Thanks for the reply Herbs, than is actually  the one I used to use, so I did order one four weeks ago on Amazon, but it never arrived, getting it refunded.

Regards

Peter

Here is one

https://motornuts.co.uk/aa-solar-panel-car-battery-charger?uilang=1&gclid=EAIaIQobChMI6Ozf4pLr6AIVUO7tCh2NrgWdEAQYASABEgIKR_D_BwE

[bearwood]

Many thanks John

I've ordered this one, so fingers crossed.

Peter

[OldTrout]

Peter,

Beware. This may not do what you want. I had one of these AA panels and sent it back.

Note the Peak output is 2.5W i.e. maximum current into 12V Battery is about 200mA. The average over 24 hrs will be much much less. Bitprius tells me the drain on the Battery from the alarm is about 50mA on the 450h. (There is the self discharge too.) I assume this is going to be about the same for other models. He suggests that a 20-30W panel is required.

I bought a 20W panel but its claims are bogus and I suspect many others are too.

The solar radiation at noon at the equinox (about now) at latitude 51 is about 800W per square meter. My panel was about 40cm x 16cm i.e. about 0.064 square meters. Thus the radiation on it will be about 50W. Now factor in the conversion efficiency and 20% would be very good and it is down to 10W. To get this you need the panel  square to the sun. Lay it in the car, even stick it to the inside of  front or rear windscreen and it will not be square further reducing output. The glass of the windscreen will also reduce it further.

My conclusion is that unless you buy a much bigger panel you may slow down the running flat but you will not prevent it.

Others may disagree.

The Lexus mail I received this week says switch on the car for one hour every week (and don't have A/C on or listen to radio etc). This will work.

John 

[Thackeray]

5 hours ago, OldTrout said:

The Lexus mail I received this week says switch on the car for one hour every week (and don't have A/C on or listen to radio etc)

I saw that email too. There might be an argument for running the air conditioning once a week too. There are the usual arguments that the seals will dry out if you don't use it and it will then lose gas or worse, start to seize up. Repairs for the air conditioning could well be more expensive than buying a new 12v Battery. I think I will keep my air conditioning going when I run the car from time to time.

[Britprius]

Running the AC could be self defeating for charging both the 12 volt Battery and the HV Battery. To run the AC the cabin fan needs to be on using the 12 volt Battery, and on your hybrid the compressor can use up to around 5000 watts of energy from the HV Battery to run it along with it's other duty of charging the 12 volt Battery.
The compressor is not engine driven, and does not have a rotary shaft seal associated with normal engine driven compressors as a source of leakage. 

John.

[matt8]

1 hour ago, Britprius said:

Running the AC could be self defeating for charging both the 12 volt battery and the HV battery. To run the AC the cabin fan needs to be on using the 12 volt battery, and on your hybrid the compressor can use up to around 5000 watts of energy from the HV battery to run it along with it's other duty of charging the 12 volt battery.
The compressor is not engine driven, and does not have a rotary shaft seal associated with normal engine driven compressors as a source of leakage. 

John.

Are you saying that using the AC even when the car is in "Ready" is draining the 12V Battery, John? Or, is the cabin fan only powered by the 12V Battery?

And, that there are no seals to seize up in the Is300h?

 

[Herbie]

1 hour ago, Britprius said:

To run the AC the cabin fan needs to be on using the 12 volt battery

On a normal car the Battery is only used to crank the engine. Once it fires and the alternator is spinning it's the alternator that supplies all of the car's electrical demands, so is it not the same for hybrids, ie, once the hybrid system is READY does our equivalent of the alternator, the DC/DC converter, not power the cabin fan?

[Britprius]

34 minutes ago, Herbie said:

On a normal car the battery is only used to crank the engine. Once it fires and the alternator is spinning it's the alternator that supplies all of the car's electrical demands, so is it not the same for hybrids, ie, once the hybrid system is READY does our equivalent of the alternator, the DC/DC converter, not power the cabin fan?

Yes it does, but all the power to run the fan, charge the 12v Battery, "the reason why we are running the engine" and running the AC compressor comes from the HV Battery. The HV Battery is only being charged at a low rate with the engine ticking over, and when the engine shuts down because it is warm it is not being charged at all. It is then being discharged at a high rate trying to run the compressor, and supplying all the 12v loads "screen, pumps, cabin fan ect". There is no regen from where it would normally get most of it's power.
So what I am saying is running the AC uses power that could be charging the 12v Battery, and further the HV Battery will suffer the greatest loss. Try it and watch the bands on the HV Battery display vanish.

John.

[Herbie]

Thanks for the clarification John.

[Thackeray]

15 hours ago, Britprius said:

The compressor is not engine driven, and does not have a rotary shaft seal associated with normal engine driven compressors as a source of leakage. 

Many thanks for the explanation. I didn't realise there was no need to run the air conditioning regularly when the compressor is electric, unlike in conventional cars. That means I can turn it off for part of the year and save some fuel!

[NemesisUK]

15 hours ago, Britprius said:

The compressor is not engine driven, and does not have a rotary shaft seal associated with normal engine driven compressors as a source of leakage. 

@Britprius John I was just reading this lexus-tech.eu doc regarding the a/c system on my RC300h, am I correct in my understanding that the a/c compressor and it's electric motor are both immersed in oil? It does say that the actual compressor is the same scroll type used generally but just electrically driven, so would the oil immersion prevent the rotary shaft seals from drying out?

(if nothing else this COVID-19 lockdown is teaching me lots about hybrid batteries and electronics!!  )

 

[Mincey]

52 minutes ago, Thackeray said:

Many thanks for the explanation. I didn't realise there was no need to run the air conditioning regularly when the compressor is electric, unlike in conventional cars. That means I can turn it off for part of the year and save some fuel!

Every day I learn something new and useful here!

[wharfhouse]

15 hours ago, matt8 said:

Are you saying that using the AC even when the car is in "Ready" is draining the 12V battery, John? Or, is the cabin fan only powered by the 12V battery?

And, that there are no seals to seize up in the Is300h?

 

I thought that air con systems had other o rings / seals in the pipework and connectors that could dry out unless the air con is run regularly for the oil in the gas to circulate around the whole system? - Must say on all the cars I've owned with air con climate control I have always left it on auto permanently anyway and let it do its own thing - I've paid for climate control so might as well use it to the full...! 

[Britprius]

54 minutes ago, NemesisUK said:

@Britprius John I was just reading this lexus-tech.eu doc regarding the a/c system on my RC300h, am I correct in my understanding that the a/c compressor and it's electric motor are both immersed in oil? It does say that the actual compressor is the same scroll type used generally but just electrically driven, so would the oil immersion prevent the rotary shaft seals from drying out?

(if nothing else this COVID-19 lockdown is teaching me lots about hybrid batteries and electronics!!  )

 

The compressor in the hybrid Toyota/Lexus vehicles is a sealed unit much like you fridge or freezer. However it is a scroll compressor directly driven by a 3 phase AC variable speed motor immersed in the same oil, and gas as the compressor so there is no need for a rotary seal. The oil, and gas help cool the motor, and this is why the oil used in the AC system is very specific as it must also have high voltage electrical insulation properties. The oil is designated ND11.
Normal AC systems use PAG oil, but this oil is conductive to electricity, and under no circumstances should it "or even equipment contaminated with it" be used to refill the AC system.
If the AC system does become contaminated with even a small amount of PAG oil a ground fault will occur in the motor perhaps weeks or months later. This will force a high voltage leak code, and shut down the car completely for safety reasons.

John.

[NemesisUK]

Thanks John 

I've also learnt that the a/c on my RC is controlled by a three layer 'neural network'! 

[Thackeray]

14 minutes ago, NemesisUK said:

I've also learnt that the a/c on my RC is controlled by a three layer 'neural network'! 

That sounds interesting. Does it say what the three layers are?

[NemesisUK]

8 minutes ago, Thackeray said:

That sounds interesting. Does it say what the three layers are?

A couple of excerpts 

From this doc. 

Air Con System Description.pdf

[Herbie]

37 minutes ago, Britprius said:

Normal AC systems use PAG oil, but this oil is conductive to electricity, and under no circumstances should it "or even equipment contaminated with it" be used to refill the AC system.
If the AC system does become contaminated with even a small amount of PAG oil a ground fault will occur in the motor perhaps weeks or months later.

A few months ago one of the members on here took their RX400h to Halfords for a re-gas of the AC and they just used one of the small cans they stock on the shelves rather than a proper machine. It caused all sorts of problems and the topic ran to about 6 or 7 pages if I remember correctly - I've had too much beer since then so things are a bit hazy and you should look it up for yourselves if anyone's interested in the whole sorry saga.

[Thackeray]

10 minutes ago, NemesisUK said:

A couple of excerpts 

From this doc. 

Air Con System Description.pdf 3.24 MB · 0 downloads

Actually, I didn't find this as interesting as I hoped.

There may be more to it, but to me this just seems a complicated way of saying they measure temperature inside and out, plus heat from sun, then adjust airflow temperature, speed and direction accordingly. I'm not sure that this is a big step forward in car aircon but I'm probably missing something.

A genuine big next step for car air conditioning would be to take into account how hot the driver and passengers are feeling. A sensor to measure their forehead temperatures could feed data to the aircon system and increase or decrease airflow and temperature accordingly. (Maybe this has already be developed.)

As an added benefit it could also tell you if you've got coronavirus. (The microphone would have been counting how often you cough). If the car comes up with a positive diagnosis, the windows would close and the doors would lock and the hazard lights would flash until soldiers dressed in hazmat suits arrived to take you away to an isolation unit.

[NemesisUK]

I agree William, I think it's a grandiose term for something that's not really what I understand as a learning neural net. It does though show how relatively complicated it is to control an a/c system.

I do believe that the monitoring of driver/passenger temperature has been implemented, just cannot recall which marque it was. I think the 'neural network' in the Lexus is trying to account for how individuals experience temperature depending on environment.

Clever stuff all the same.. 

[Thackeray]

7 minutes ago, NemesisUK said:

Clever stuff all the same.

Absolutely. Very sophisticated.

Just not sure it's using a neural network in its usual meaning.

[matt8]

4 hours ago, Britprius said:

Normal AC systems use PAG oil, but this oil is conductive to electricity, and under no circumstances should it "or even equipment contaminated with it" be used to refill the AC system.
If the AC system does become contaminated with even a small amount of PAG oil a ground fault will occur in the motor perhaps weeks or months later. This will force a high voltage leak code, and shut down the car completely for safety reasons.

John.

This is the stuff I learn that I am glad to learn, but wish I didn't know. It scares me to death that it's so easy to damage things. I don't use main dealers for servicing and wonder how commonplace knowledge like this is. Probably not very.