12v battery problem hopefully

royoftherovers · September 11, 2019

I read a report recently which pointed out that a recent survey carried out in the UK showed that on average we use our cars for only 4% of the time.

If this is true (and I have no reason to doubt it) if we ran an airline on 96% non flying time, then we would be out of business in no time at all.

Bob99 · September 11, 2019

I tend to charge the 12v Battery during winter using my ctek charger. If your Battery is showing signs of deterioration after less than a year Roger I too would be concerned. Was it replaced with the correct spec Battery

reeac · September 12, 2019

I've only used the nearest Lexus dealer for this car which is where I bought it so they changed the Battery which says "Toyota" on the side so I assume that it's the correct one.

wharfhouse · September 12, 2019

23 hours ago, reeac said:

My late -65 IS300h went in for its 4 year service last week and came back with a note on the Hybrid Health Check that the auxiliary battery shows signs of deterioration and that I should contact my Service Advisor. I did this but the only advice that I received was to use the car more. Apparently during the HHC the auxiliary battery voltage dropped to a level where warning beeps were emitted. This is with a replacement battery supplied last November. I have taken to monitoring that battery voltage at the time of switching on just to see how long the car can be left and the voltage so far is never less than 11.5 which is sufficient although remarkably low for a 12 v AGM battery. Anyway I received an email from Lexus HQ asking my opinion regarding the service and so I took the opportunity to spell out the history a bit with the underlying question that I've never before owned a car that required such regular use in order to keep it in a startable condition ( think 2 week holiday with car left in airport car park). My suggestion to Lexus is that the battery is under specified for its task. I await developments.

I suspect that the test threshold may be the issue - I had a similar warning at my last service (10k miles ago now) but the dealer said that it is not uncommon and not to be concerned as its often that the test is done after the car has been sat for a while drawing current from the 12v Battery,for example during the a service. I haven't had any problems since the last service but have another coming up in a couple of weeks so will see if the check reports the problem again at that one. My IS 300h is a 64 reg, 79,000 miles and still original 12v Battery. I do keep one of the emergency jump Battery blocks in the glovebix just in case but never had to use it yet.

cidermonster · September 27, 2019

Good evening all

I thought I'd contribute to this thread as I too experienced electrical issues which appeared to be due to the Battery. I did charge it but replaced it as a precaution but had lost the infotainment, no stereo, nav screen. The only thing that works is the CD eject button.

I've replaced the Battery and checked all the fuses, the likely candidates in the passenger footwell and under the bonnet. Used the Carista OBDC connector and there are no faults. I'm wondering whether the infotainment is faulty after the electrics going haywire.

Any ideas if there is a procedure for resetting the system? I've tried the disconnect Battery, keep the stereo button pressed for 5 seconds with ignition on (foot off break).

Thanks

Pete