Battery Problem

[Agnelo Correa]

I own a Lexus IS200 SE. I face a very pecular problem. The Battery of my car gets discharging. This is my 4th Battery in the last 4 months. The Battery is installed by Lexus bristol and is a 570Amp EN Battery. Once I leave the car without a run for 4 days the Battery is completely dead. Initially I thought some light was left ON and thus the Battery discharged. After I faced a problem with the 2nd Battery I started doing analysis in detail. When the car was alarmed and not started for 4 - 5 days, the Battery got flat. Took it to lexus and they advised that probably there would be the security alarm system which is draining the Battery. To check this fault, I parked the car in my garage and left the car disalarmed. Still my Battery would drain after 4 - 5 days. I bought a tickle charger from Maplin and tried to recondition the Battery but still it failed as the tickle charger would not charge the Battery. I removed all the fuses and also the main fuse to check if the Battery drained and I still found the batery draining. Now the actual readings.

Battery - 570 Amps

When ignition is switched off - drain current - 20 - 30 mA

Battery Voltage - 12.64 volts. When new. Started the car - Voltage @ 800 rpm - 13.04 - 13.1 Volts. when RPM in increased to 1200 rpm - the voltage form alternator - 13.12 volts and above. Switched the car off and checked for the current drain - 20 - 25 mA.

Car driven from work to home - Battery charge after the car is switch off for almost 2 hrs - 12.7Volts. Car left overnight without starting - Voltage drops to 12. 46 volts. If left for 2 days the voltage drops below 12. 3 volts.

Lexus has done all the check on the car and they confirm there is no issue with the alternator, electricals etc,. They have not faced such an issue before. Can someone advise me on what needs to be done to get this issue fixed or has anyone faced such a similar problem before.

[steve2006]

Hello and welcome to the LOC.

You certainly seem to have covered all possible causes comprehensively and the parasitic current draw is within normal parameters.

From your readings the charging circuit seems to be functioning correctly as confirm by Lexus.

Not sure what to suggest from here unless all the batteries are faulty which seems highly unlikely.

I found this link which make intersting reading

http://www.diagnosticnews.com/tech/parasitic-battery-drains/

[doberdog]

Hi mate bought one of these things a few Weeks ago and having the same problem, also at idle with lights on etc the Battery drains but bring the revs up slightly and its charging again.

I've been a bit lazy so far as am fed up with the amount of problems I've had in such a short space of ownership so haven't gone in to this problem much yet - its on a very long to do list. I do know however that quite a few owners have this problem.

If u find a solution please post or if I get off my arse and find one I'll do the same

[clifton 94]

hi try disconnecting the Battery and leave the car for a couple of days then try to start the car if the Battery is flat then you know if the Battery is at fault or not

[jay_russell]

go through the fuses and unplug 1 a night to see if you can locate the drain. thy the radio and other things first like heated seats and windows / mirrors. you might be able to find out what it is draining the Battery.

[The Transporter]

If you can get your hands on a clamp meter, clamp it round the live wire from the Battery, note the number of amps being drawn and then one by one remove fuses and note if the reading goes down as you pull the fuses...

[north]

I had the same thing... and found the problem When you are not going to use the car the next day turn of the lights!

when you leave it on auto it will be using power for the light sensor which leads to the draining of the Battery.

Stupid thing is it is in the owners manual... they should have realised this at the dealer.

[Von]

I have a similar problem and was about to buy a new Battery, but decided to check here first.

My Battery indicator says my Battery is OK, but if my radio or ignition stays on for 1 min or so with out starting that it for my Battery!

Unfortunately for me I did not get a User/Owners Manual with my IS200.

I must ask which Lights are you referring to Errol?

[north]

The main beam on the light stalk ... if you put that on auto the light sensor stays active and drains the Battery in 4 days time. It doesn't switch the lights on but apparently it keeps trying to turn the lights on zapping power away when it is dark enough.

[Von]

Thanks for that bit off light, but i have not been using that feature. I make sure to switch of the light switch. As I'm new to Lexus.

[north]

also the rear window defogger can zap power away especially if you have music on and seat heating ;) . At first I always used everything now the lot is of unless it is needed but mine Battery drain is gone and can leave the car standing for weeks without starting. (that used to be 4 days and then the Battery would be under starting power... 10.3 volts to be precise)

I also loosened up the power steering pump a bit it was to tight so the car needed more power to start up ( it was so tight i couldn't even push it down so I gave it some slack)

Anyway it solved my Battery problem hope that it helps you a bit