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I have a RC 300H and when I am going slow up to 30mph and using the Battery it hardly seems to last long?  Is this standard ?  The Battery does not seem to hold its charge and was only replaced 6 months ago.  Some people tell me it is not really worth it anyway unless you are driving slow around a car park?  Thanks

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Hybrid is NOT electric. Battery is small and its purpose is to recover and distribute energy otherwise wasted. And you have not to recharge it,as when necessary it is recharged by thermal engine. In EV you can just move for very few miles.

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1 hour ago, Pcoulter said:

I have a RC 300H and when I am going slow up to 30mph and using the battery it hardly seems to last long?  Is this standard ?  The battery does not seem to hold its charge and was only replaced 6 months ago

There seems to be a bit of confusion here Paul.

The Battery that drives the car is the traction (hybrid) Battery and, depending on the model of car, can be anything from about 200V to 300V. It would be extremely unusual for that Battery to need replacing, especially on a 2017 car, so I'm assuming you're talking about the 12V Battery when you say it was replaced 6 months ago?

Hybrids don't have a traditional starter motor (or alternator either) and all the 12V Battery does is to boot the computers and get the hybrid system into READY mode, along with a couple of other things. Because this doesn't take a lot of power (about 20A instead of the 300A or more that a conventional starter motor needs to crank the engine) Lexus only fit small capacity 12V batteries, which is why it goes flat quite quickly if the car isn't used regularly.

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6 minutes ago, Pcoulter said:

Thanks a lot Herbie.  Good point I am not sure what battery it was?  I did wonder why the salesman told me he could drive to work on the battery........  and I can just about get through a car park lol

Never trust a used cars salesman!

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15 hours ago, Pcoulter said:

I did wonder why the salesman told me he could drive to work on the battery........  and I can just about get through a car park lol

Sadly, unless he lives very close to work, that was just an out-and-out lie. If you could drive it on Battery alone you wouldn't get more than a couple of miles before the traction Battery was flat.

For the car to work, three things are needed - the 12V Battery, the high voltage traction Battery and the petrol engine. If any one of those three are 'missing' the car won't work, which is probably why Toyota called the system the Hybrid Synergy Drive.

As I said earlier, the 12V Battery boots the computers and brings the car into READY mode, at which point you can drive off on Battery power only if you want to. When the hybrid system decides it needs the ICE (Internal Combustion Engine) to run, it energises Motor/Generator 1 (MG1) and uses it to spin the engine up to 1,000rpm before applying fuel and a spark to fire it - which is why there's no starter motor.

Anything that would normally be driven by a belt from the engine, such as power steering pump, aircon compressor etc., etc., is driven electrically instead, because the ICE doesn't run constantly.

There's no alternator either, so the 12V Battery is charged by means of a DC/DC converter, which is basically a box of electronics that takes the (we'll say) 300V of the traction Battery and drops it to approximately 14.5V to run all the 12V systems and keep the Battery charged. Other boxes of electronics do the same for other systems. For instance, I think the power steering works on 48V; the aircon compressor is run by a 500V 3-phase AC variable frequency motor and MG1 and MG2 are both 650V permanent magnet motors.

Try to never run out of petrol but if you do, you'll need to put in at least 10 litres (better with 15) before attempting to restart. If you unsuccessfully try to restart it more than 3 times, the hybrid system can lock out and you'll need a dealer to get it going.

If your aircon ever needs to be regassed, make sure that whoever does it uses ND11 oil (or equivalent) and not the 'normal' PAG oil. The refrigerant gas is the same as a conventional car, but the windings of the aircon compressor motor are immersed in the oil for cooling purposes and ND11 does not conduct electricity.

Hope that helps :thumbsup:

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17 minutes ago, Herbie said:

Sadly, unless he lives very close to work, that was just an out-and-out lie. If you could drive it on battery alone you wouldn't get more than a couple of miles before the traction battery was flat.

For the car to work, three things are needed - the 12V battery, the high voltage traction battery and the petrol engine. If any one of those three are 'missing' the car won't work, which is probably why Toyota called the system the Hybrid Synergy Drive.

As I said earlier, the 12V battery boots the computers and brings the car into READY mode, at which point you can drive off on battery only if you want to. When the hybrid system decides it needs the ICE (Internal Combustion Engine) to run, it energises Motor/Generator 1 (MG1) and uses it to spin the engine up to 1,000rpm before applying fuel and a spark to fire it - which is why there's no starter motor.

Anything that would normally be driven by a belt from the engine, such as power steering pump, aircon compressor etc., etc., is driven electrically instead, because the ICE doesn't run constantly.

There's no alternator either, so the 12V battery is charged by means of a DC/DC converter, which is basically a box of electronics that takes the (we'll say) 300V of the traction battery and drops it to approximately 14.5V to run all the 12V systems and keep the battery charged. Other boxes of electronics do the same for other systems. For instance, I think the power steering works on 48V; the aircon compressor is run by a 500V 3-phase AC variable frequency motor and MG1 and MG2 are both 650V permanent magnet motors.

Try to never run out of petrol but if you do, you'll need to put in at least 10 litres (better with 15) before attempting to restart. If you unsuccessfully try to restart it more than 3 times, the hybrid system can lock out and you'll need a dealer to get it going.

If your aircon ever needs to be regassed, make sure that whoever does it uses ND11 oil (or equivalent) and not the 'normal' PAG oil. The refrigerant gas is the same as a conventional car, but the windings of the aircon compressor motor are immersed in the oil for cooling purposes and ND11 does not conduct electricity.

Hope that helps :thumbsup:

Very helpful. That answered fully.  If you get a chance can u look at my other question about the oil maintenance....... that I no clue about  .  Thanks loads 

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