Is300 Very Rapid Battery Drain

[Swifty2005uk]

I have owned an IS300 for about 6 weeks now and it has run perfectly except for a Battery problem which has happened twice now.

A couple of weeks after buying it we were parked in a car park and the engine was not running but the climate control was running and so was the radio,the ignition was on and also the satnav screen,we were parked for about 5 minutes and when I tried to start the car all I could hear was a rapid clicking noise coming from what I guess was the starter motor and the engine would not turn over.

I phoned my local Lexus dealer who said it sounded like a flat Battery and that I should call the RAC.

The RAC arrived and the car started first time after he had connected the jump leads,he checked that the car was charging up the Battery and that the Battery itself was in good condition and everything was fine but he gave me a form to give to my Lexus dealer to say the Battery wasn`t up to much so I could get a replacement under warranty.I explained what had happened to the dealer but they said It wouldn`t be a Battery problem as the car had been starting no problem before and after the breakdown and that we had probably flattened the Battery by moving the electric seats with the engine not running.

The same problem just happened again today,I was talking to a friend,he jumped in the car turned the ignition on so he could see what the satnav screen looked like and we chatted for about 2 minutes,I told him to start up the engine and take the car for a drive but all we heard was the ticking from the started motor,we connected some jumps leads and it started first time and has been no problem since,the electric seats were never moved so does anyone have any idea why this is happening?

[Mr Morse]

Get a multimeter, set it to read volts and test the Battery across the +ve and -ve terminals.

With the engine off, it should read 12v, with the engine running it should read 13.8v.

Anything less and one or more of the cells are dead. Under normal running conditions a bettery should last 4-5 years unless you are running some heavy ICE.

Take it back to the dealer and demand a replacement.

[IS300]

You should have a Volt-Meter on your dash, what reading do you get with just the ignition on?

[MacRS200]

Agree with Mr Morse probably duff Battery.

[Swifty2005uk]

The gauge on the dash shows it has 13.8v with engine running,the RAC man checked the charge on the Battery etc with a multimeter and said it was all ok,the car starts first time every morning but if its left with the ignition switched on for a couple of minutes it won`t start.

The car is a 51 plate not a brand new one,it has done 43k,stereo is standard.

[chips229]

It could be a bad Earth or bad connection on one of the wires going to the starter motor.

[IS300]

If you leave the ignition on for say 5 mins, does the volt-meter on the dash drop slightly below 12v ? If i does then the Battery is on its last legs

[New Bhoy]

The same thing happened to me just after I bought my IS300, with a multimeter the Battery would read not bad ( just above 12 volts) but when I tried to start the car it would turn over but reluctantly but started then if I left anything running without starting the car I got the clicking .

Took it back to the garage and they said the Battery was ok as it was reading over 12 volts, forced the garage to send it down to there Lexus branch as I only had the car 4-5 weeks and the lexus boys replaced the Battery and it has been cool since. :D

[Fargo]

i would demand the dealership sorts the problem,, the Battery should have at least 90odd hours standby time, ie when NOT being charged.

simply using the electric seats or any other electrical item whilst engine is not running will NOT kill a healthy Battery..

[BernardTamHK]

right ... i agree with all the above.....

but, I also want to point out ... having the climate control (auto) when your engine is off (with the AC option on) ... is a big no no.

The AC drains the Battery like a thirsty vampire at a redcross buffet...

I once forgot to turn the AC off ... and turned down the engine while waiting for someone .... 2 mins later, .... dead with no juice left!

[Swifty2005uk]

I went to my local dealer today and explained everything to them again,they said having the aircon on and also moving the seats would take a fair bit of charge out of the Battery,they tested the Battery and said it wasn`t in top condition and needed to b replaced.They warranty doesn`t cover the Battery but as I have only had the car a few weeks they agreed to a replacement as a good will gesture.

Thanks for all the replies.

[ColinBarber]

right ... i agree with all the above.....

but, I also want to point out ... having the climate control (auto) when your engine is off (with the AC option on) ... is a big no no.

The AC drains the battery like a thirsty vampire at a redcross buffet...

I once forgot to turn the AC off ... and turned down the engine while waiting for someone .... 2 mins later, .... dead with no juice left!

←

AC, unless you have a RX400h or Prius, running from the engine not the Battery. The fans don't use that much power, if your Battery went flat with two minutes of the fans running then you need a new Battery.

[BernardTamHK]

right ... i agree with all the above.....

but, I also want to point out ... having the climate control (auto) when your engine is off (with the AC option on) ... is a big no no.

The AC drains the battery like a thirsty vampire at a redcross buffet...

I once forgot to turn the AC off ... and turned down the engine while waiting for someone .... 2 mins later, .... dead with no juice left!

←

AC, unless you have a RX400h or Prius, running from the engine not the Battery. The fans don't use that much power, if your Battery went flat with two minutes of the fans running then you need a new Battery.

←

right ... the fans don't use much juice, but the compressor for the refrigerant does ... I also had the stereo and lights on .. so that didnt help!