Herbie

There's no specific procedure John, it simply shows where the screws are and what to take apart; certainly nothing that could affect the electronics or the key-car communication. I'll hazard a guess that it's either a duff battery, reverse polarity, or just not making good contact where it should.

This may help you for future reference:

You're welcome James

So what's the point you're making Barry because I'm not sure? The quote from CTEK's website doesn't seem make sense - maybe something was lost in translation or they didn't quite understand the question: First of all, we already know that the negative terminal of the battery is connected to the chassis so how can any battery management system know whether the CTEK is connected to the actual battery post or to a random screw six inches away? Answer: It can't - or at least, not so as to make any difference. Every electrical conductor has resistance, so having the CTEK directly connected to the battery post will obviously have the least resistance - let's say 0 Ohms. Connect it to a screw six inches away and that resistance between the lead and the battery post may increase, say to 0.001 Ohms. Connect it to a screw six feet away and the resistance between the lead and battery post will increase again, say to 0.1 Ohms. In other words, the accuracy and operation of any BMS will be affected by where you choose to locate that negative lead, which would make it a very poorly designed system, which is why I think this is a red herring and why I still believe that BMS or not, there is still no viable electrical reason to avoid connecting directly to the negative battery post. The question had nothing to do with the alternator running, only whether the negative lead could be connected to the negative battery post instead of the chassis, so again I think there's some confusion on CTEK's part

That says it all. The negative terminal of the battery has a great big cable connecting it to the body/chassis/engine. This connection forms a continuous metallic conductive path around the car so that any piece of metal, any bolt, any screw, anywhere in or on the car that is not specifically insulated from it, basically becomes the negative battery terminal. It simply does not matter whether the eyelet is connected directly to the negative battery terminal or to some nearby screw. It may possibly be some safety procedure (thinking of some stray spark igniting the hydrogen gas coming from the charging battery somehow) but electrically speaking, it just does not matter - although I'm happy to be corrected if anyone can prove otherwise and will gladly hold my hand up.

But that wouldn't be a hybrid BMW though would it? As Colin said above, the 12V batteries on hybrids are very small with a limited capacity. All my previous cars have had a battery of at least 75Ah minimum, whereas my RX450h has the biggest engine (3.5litre) and weighs the most (almost 2tons) but has the smallest battery at about 45Ah if I remember correctly. The starter motor of a normal car will draw upwards of 300A when cranking the engine, but hybrids don't have a traditional starter motor and, as you'll see below, my RX450h only takes 15.32A to get it into the READY state instead of 300A or more. The 12V battery only boots the computers and gets the hybrid system up and running; it doesn't have to crank the engine, which is why it can be smaller. I carry a jump start battery pack in the glove box, very much like this one for peace of mind. The one I've linked to is more powerful than you would need for your own car but it could enable you to help someone else if they had a flat battery because you should never use a hybrid to jump start another car, although you may be alright if it's another hybrid. The reason for this is that a hybrid doesn't have a traditional alternator. Instead, the battery is charged by a DC/DC converter that 'steps down' the 288V of the traction battery to about 14.5V and these converters aren't as robust as a traditional alternator and can only supply a fraction of the current that an alternator could. You don't want a car with a flat battery trying to draw huge amounts of current from your converter, or the very expensive magic smoke inside it could escape with a bang. It is alright though, for a hybrid to be jump started by another car if you didn't want to buy one of these battery packs.

There really isn't much to say about it. All you are doing is supplementing a dodgy 12V source by piggybacking a good 12V source onto it. 12Volts is 12Volts and whether you use the jump start terminal in the fuse box under the bonnet or connect directly to the battery terminals, it doesn't matter because 12Volts at the front or 12Volts at the back (if the battery is in the boot as it is in the RX450h) is still 12Volts, wherever you connect it. The most important thing of all is to make sure you connect it using the correct polarity, ie, Positive to Positive (or + to + or red to red) and Negative to Negative (or - to - or black to black). Once the jump start battery pack is connected, go through the normal start-up routine and wait for the READY light to come on, then disconnect the battery pack and Robert is your mother's brother.

I have a 63-plate RX450h Advance and if I unlock the car with either keyless entry or by manually pressing the zapper buttons, there's complete silence until I open the door and then you can hear the brake control system activating - but not on the approach to the car, only when the door courtesy switch is operated by opening.

There is absolutely no need to disconnect the battery before charging it Piers. As I've said before, all you're doing is supplementing one 12V source by piggybacking another 12V source onto it, so as far as the car is concerned it still only 'sees' or knows that there's 12V there - it doesn't know that a charger has been connected. And if anyone is going to say that to charge a 12V battery you have to use more than 12V, ie, about 14.5V, yes, this is correct. This is exactly what the car's own alternator is designed to do, so whether the battery gets a charging voltage from an external source or from the car's own alternator, there's no difference.

That's not actually what you said in your post in the New Members forum; you said there was "no drive", which I'm taking to mean a transmission problem. So to avoid confusion, when you start the engine and move the selector lever to either D or R, does it actually take up drive, ie, make a very slight lurch and the engine note drops, and the problem comes after that when you try to accelerate? Or are you saying that it doesn't even take up drive?

Accessory socket/cig lighter are only energised when the ignition is on, so no, you can't plug a solar charger in there. Most solar chargers come with a variety of connectors, one of which is an OBD2 plug like the one below:

That is definitely NOT normal. I can assure you that the inverter cooling system does not run with power off. Firstly, how could it and secondly, what would there be to cool? The inverter only has things to do when the car is energised.

Sincere condolences to you and yours at this very sad time Qamar.

Could be battery connections though; those symptoms are often an indication of battery and/or battery-related problems. Disconnect the battery and clean both the battery posts and the cable clamps, as well as the other ends of those cables and the engine to body earth strap, then make sure to get a really good tight connection when replacing them. The battery falling below 11V is not the only reason for the engine to fire up. The engine is the only source of heat for the cabin so it'll fire up as and when necessary to keep the cabin temperature up to whatever the system is set at. You really need a multimeter to check standing battery voltage against the chart below, then do a second check with the car in the READY state (the equivalent of having the engine running and the alternator spinning on an ordinary car), which should read about 14.5 - 14.7V if the charging system is working as it should. If that doesn't sort it, the next step would be to get an OBD2 reader (or preferably a laptop with Techstream) to read any stored codes.

No, it was a 2005 RX300. I believe it is possible to do the 450h but as much as I loved having LPG I wouldn't convert a hybrid. The hybrid system is a very complex beast anyway and I think that adding another level of complexity into the equation would just be asking for trouble.

To be honest it's not all it's cracked up to be anyway. OK, it tells you when the pressure is down in a tyre but it doesn't say which one of the four it is!

Sounds like the latching mechanism has seized so a squirt of something like WD40 on it and a few open/close ops may help.

This is a link to Paul Frost's eBay page He trades on the Bay of Fleas as lexussparesdirect. He's very knowledgeable, very helpful, and his parts are very reasonably priced. His business details are:

I only have the space saver so can't say for sure, but I would be very surprised if a full-sized wheel could be kept in there. Mind you, this space saver is the first spare wheel of any sort that I've had in the last 15 years. Up to getting this hybrid, all my cars over the last 15 years were converted to LPG and the gas tank was located in the spare wheel well instead of the spare. I just carried around a can of Holts Tyreweld and a little 12V compressor for small punctures, anything bigger would be dealt with by my breakdown cover.

My late 2013 (November) RX450h Advance has it.

As I said in a different topic: I'm not trying to come over as a 'know-it-all' because obviously, I don't, but I'm a time-served electrician by trade. When the factory closed down I became a telephone engineer on BT, and after a back injury led to medical retirement I'm now self-employed doing computer repairs. I'm also a licenced radio ham and dabble in electronics as a hobby. I mention that, not to blow my own trumpet, but just to explain that I've been in and around the electrical/electronics fields for more than 40 years. In my humble opinion (and this goes for both jump starting and charging), 12V is 12V. It just doesn't matter whether it's at the front or the back, it's still 12V and all you're doing is piggybacking one 12V source onto another 12V source. The only thing to worry about is to make sure you connect with the correct polarity. Having said all that, you can't blame me if something does go awry

Geoff, if you put the meter on the 20V DC* range and put the probes across the battery while the car is just standing there, you should get a voltage reading that you can compare to this chart: If you then put the car into the READY mode and test again you should see about 14.5V, which shows that the charging system is working as it should. I'm not trying to come over as a 'know-it-all' because obviously, I don't, but as I've said in other topics I'm a time-served electrician by trade. When the factory closed down I became a telephone engineer on BT, and after a back injury led to medical retirement I'm now self-employed doing computer repairs. I'm also a licenced radio ham and dabble in electronics as a hobby. I mention that, not to blow my own trumpet, but just to explain that I've been in and around the electrical/electronics fields for more than 40 years, and in my honest and humble opinion I cannot find any reason as to why the manual would say that the negative (earth) cable should be disconnected from the battery unless someone was attempting to use an old-style charger that their dad used to use 30 or 40 years ago. Modern 'intelligent' chargers have all sorts of magical wizardry to monitor voltage and current levels, and safety circuitry too that monitor temperature, charge rate and other parameters. I can't see any reason at all to disconnect the negative cable when using something like the ctek or a Noco. Having said that, I can't be held responsible if something did go awry *If the meter doesn't actually state AC or DC but uses symbols instead, AC is denoted by a wavy line and DC is a solid horizontal line with a dotted line underneath it.

Hi Chris, just sent you the same message.

Fair enough, thanks - every day's a school day

His car is Left Hand Drive (LHD) so his blue plug may be on the opposite side to yours.