Battery Drain

[CJHYBRID]

This is well known to us Hybrid drivers as the aux Battery on our cars is small and drains

Over time. Principal is the same though being a Lexus your car has lots of kit and things like Alarms Central Locking Bluetooth etc all drain the Battery when left any length if time.

Some pointers if Battery is a couple of years or more old suggest you replace it.

AIso

Suggest you do not use Lexus direct replacement batteries they are not their finest attribute go for a Bosch or Varta with a guarantee.

Don't laugh at Solar chargers they work any car being left for a period of time will have Battery drain and the solar charger trickle

Charges it. AA do one that fits your Odb2 socket for around £35 this

Socket has power to it all the time it's normally located under the dash but I am not sure on the Sc

Another tip is to make sure the top of the Battery is clean (baking soda and a little water) as grease and grime promotes Battery discharge .

Hope this helps

Chris

[ambermarine]

This is a common occurence on The LS400 mark 4 I bought one last year with 18k on the clock the Battery was shot and it had been wired for a solar dashboard charger,I checked with previous owner who had it 13 years and he said it would flatten the Battery after 10 days if not run which doing the mileage he did happen a lot in first year.

I don't have enough light in my garage for a solar charger nor do I like them .I have my car on a an intelligent golf caddy charger outputting 2 amp because if you use the 600 ma chargers that are on sale they are not up to the job and are playing catch up all the time and burn out after a week.

The reason for the discharge is the security system that unlike earlier LS400 models cannot be switched off.

I presume the SC range will be similar if not the same as it carries the same power unit and electrical system.

[alphacat]

This is well known to us Hybrid drivers as the aux battery on our cars is small and drains

Over time. Principal is the same though being a Lexus your car has lots of kit and things like Alarms Central Locking Bluetooth etc all drain the battery when left any length if time.

Some pointers if battery is a couple of years or more old suggest you replace it.

AIso

Suggest you do not use Lexus direct replacement batteries they are not their finest attribute go for a Bosch or Varta with a guarantee.

Don't laugh at Solar chargers they work any car being left for a period of time will have battery drain and the solar charger trickle

Charges it. AA do one that fits your Odb2 socket for around £35 this

Socket has power to it all the time it's normally located under the dash but I am not sure on the Sc

Another tip is to make sure the top of the battery is clean (baking soda and a little water) as grease and grime promotes battery discharge .

Hope this helps

Chris

No it doesn't help at all.. The SC shouldn't have issues like a hybrid because it isn't a hybrid its a normal car and it should not drain the Battery under normal circumstance's at least not in less than 2 months or so. Grease and grime do not 'promote' Battery discharge it just provides a resistance that has to be overcome. I do laugh at solar panels as they should not be required. They fix nothing. The answer is to fix the problem. Now its clear a number of SCs do have a problem masking it isn't clever solving it is.

[alphacat]

This is a common occurence on The LS400 mark 4 I bought one last year with 18k on the clock the battery was shot and it had been wired for a solar dashboard charger,I checked with previous owner who had it 13 years and he said it would flatten the battery after 10 days if not run which doing the mileage he did happen a lot in first year.

I don't have enough light in my garage for a solar charger nor do I like them .I have my car on a an intelligent golf caddy charger outputting 2 amp because if you use the 600 ma chargers that are on sale they are not up to the job and are playing catch up all the time and burn out after a week.

The reason for the discharge is the security system that unlike earlier LS400 models cannot be switched off.

I presume the SC range will be similar if not the same as it carries the same power unit and electrical system.

Thanks for that... I was beginning to believe the security system was an issue. but the fact that Lexus let cars suffer in this way without recall is unacceptable. Are you saying you leave the car on charge without disconnecting a Battery terminal ?? This used to be a definite no no as diodes in the alternator control unit can sometimes be blown. Not sure if it still applies, but If I am charging a Battery I always disconnect one of the terminals.

[ColinBarber]

No it doesn't help at all.. The SC shouldn't have issues like a hybrid because it isn't a hybrid its a normal car and it should not drain the battery under normal circumstance's at least not in less than 2 months or so. Grease and grime do not 'promote' battery discharge it just provides a resistance that has to be overcome. I do laugh at solar panels as they should not be required. They fix nothing. The answer is to fix the problem. Now its clear a number of SCs do have a problem masking it isn't clever solving it is.

This is not the sort of response I expect to somebody trying to offer you some help and advise. I suggest you be a little more courteous in future if you wish to remain a member of this community.

In response to your grease and grime comment I will give you the benefit of the doubt and assume you misunderstood. Chris was not referring to dirt in between the Battery terminals and the connectors, but dirt across the top of the Battery which will allow current to pass from the -ve to +ve terminals and cause self discharge. This is a real problem and is one of the issues to check for when experiencing this type of issue. Toyota recommend that if a voltage of 0.5v or higher is detected across the -ve terminal and any point on the top of the Battery casing that it is cleaned to prevent self discharge.

[alphacat]

No it doesn't help at all.. The SC shouldn't have issues like a hybrid because it isn't a hybrid its a normal car and it should not drain the battery under normal circumstance's at least not in less than 2 months or so. Grease and grime do not 'promote' battery discharge it just provides a resistance that has to be overcome. I do laugh at solar panels as they should not be required. They fix nothing. The answer is to fix the problem. Now its clear a number of SCs do have a problem masking it isn't clever solving it is.

This is not the sort of response I expect to somebody trying to offer you some help and advise. I suggest you be a little more courteous in future if you wish to remain a member of this community.

In response to your grease and grime comment I will give you the benefit of the doubt and assume you misunderstood. Chris was not referring to dirt in between the Battery terminals and the connectors, but dirt across the top of the Battery which will allow current to pass from the -ve to +ve terminals and cause self discharge. This is a real problem and is one of the issues to check for when experiencing this type of issue. Toyota recommend that if a voltage of 0.5v or higher is detected across the -ve terminal and any point on the top of the Battery casing that it is cleaned to prevent self discharge.

How dare you suggest my Battery is dirty... Chill out a bit.. It was a naf suggestion and you know it.

[ColinBarber]

not naff because I personally found some current leak across my Battery the other day. Being covered up meant it didn't get a routine wipe and even though it wasn't that dirty, once a bit of moisture was there a high voltage reading could be measured.

This issue doesn't seem to affect all SC430s - has anybody with the issue actually measured the parasitic current drain once the vehicle has been left for 10 mins after the alarm has been set? It is possible that something is drawing too much current, maybe the result of some water ingress somewhere. I assume you aren't still on the original Battery?

[ambermarine]

Alphacat ;Yes I do leave the Battery fully connected with the intelligent charger supplying the charge constantly.The exercise is to supply the Battery with replenishement power as it is used by the security system.

If you use an intelligent charger it will determine what current is being used and adjust accordingly.

The blocking diode in the alternator is not affected by overcharging as the charger senses when the Battery is at full charge and stop charging when the current is used to a certain level it restarts charging repeating the cycle.

There are a lot of cars on the market that suffer from this phenomenom ,as most are used every day it does not become an issue but as a lot of Lexus cars are second cars used on lesser occasions ,this is one way to accomodate the issue.Just as a any problem as a solution there is a solution that creates another problem The security system is disabled as soon as you insert the ignition key into the lock or if it is card the same ,if you think your car is secure enough to leave either in situ when not attended it will solve the problem,but the cars insurance will be void.

[alphacat]

Alphacat ;Yes I do leave the battery fully connected with the intelligent charger supplying the charge constantly.The exercise is to supply the battery with replenishement power as it is used by the security system.

If you use an intelligent charger it will determine what current is being used and adjust accordingly.

The blocking diode in the alternator is not affected by overcharging as the charger senses when the battery is at full charge and stop charging when the current is used to a certain level it restarts charging repeating the cycle.

There are a lot of cars on the market that suffer from this phenomenom ,as most are used every day it does not become an issue but as a lot of Lexus cars are second cars used on lesser occasions ,this is one way to accomodate the issue.Just as a any problem as a solution there is a solution that creates another problem The security system is disabled as soon as you insert the ignition key into the lock or if it is card the same ,if you think your car is secure enough to leave either in situ when not attended it will solve the problem,but the cars insurance will be void.

Thanks for that. ...

Makes sense but I am not satisfied that a car with a perfectly good Battery should become unreliable after less than 2 months without having to charge the Battery in some way.

I often leave the country for weeks and when returning I expect the car to start if its been garaged indoors, at the airport, or with some car parking company and I wouldn't expect to have it started, I am surprised that members seem to accept this is 'normal'. It never was in the past and having security systems modern electronics etc it matters not the Battery should be able to cope if it meets its spec.

With that in mind I contacted Lexus.

At first I had some response from a woman who admitted she wasn't technical but suggested my Battery was at fault and I should take the car to a Lexus dealer. I wasn't happy with that and informed them that the Battery was fine I have done charge tests and drain tests etc My Battery is clean ( terminals and the casing) and I had heard from the lexus club web site that a number of people have this issue and in some cases have changed the Battery for anew one to no avail.

I also mentioned that if a car cant be left for about two months its not reliable and I believe this issue has been identified on the 430SC because so many of us use it infrequently..

I have just had an e-mail telling me the complaint has now gone to Lexus head office for customer service so I am hoping for something sensible back.

They should at least know why we have to trickle charge a good Battery after a few weeks. Bad design or whatever.

This was a £60000 car from a company that built a rep on reliability and quality. Plugging in little solar panels whenever you go on holiday and hoping it will start when you get back is not acceptable. My car was only 6 years old when I first realised what was happening and had only done 50000 miles.

Saying all that I haven't had the problem since last May when I was out the far east for 3 weeks it seems fine but I have used it at least once a week since.

I want to know from Lexus why? They must know....

[alphacat]

I left my car at a Heathrow Meet and Greet a few weeks ago while I had a holiday in Thailand. Dropped if off and picked it up 12 days later. No problems with starting apparently... It was delivered back on time with no notifications. So it seems my car is fine for at least 12 days... still not sure after that... Point is the parking service I use may not have told me they had to start it with leads or a booster because it may be they get accused of leaving lights on etc.

So I still cant be firm that it will last 12 days.... In fact now it rarely is left that long....My latest e-mails to Lexus have been ignored. No technical help at all. Customer service just say, 'the,y of course are not technical staff' !!!! Whats the point of having customer service people who don't understand cars ??

[Essex chelle]

Hi guys, well car was left at airport for two weeks in July and started fine when we returned, we did hold our breathes as I turned the key lol, however, I've had the car off road in the garage for two months as I've been driving my daughters little Clio around whilst she is working abroad and as I am paying her insurance I thought I'd get my money's worth lol, have been going into garage every other week and starting her up, but yesterday she was flat as anything, had to have an industrial mains jump start to get her going again.

[alphacat]

Hi guys, well car was left at airport for two weeks in July and started fine when we returned, we did hold our breathes as I turned the key lol, however, I've had the car off road in the garage for two months as I've been driving my daughters little Clio around whilst she is working abroad and as I am paying her insurance I thought I'd get my money's worth lol, have been going into garage every other week and starting her up, but yesterday she was flat as anything, had to have an industrial mains jump start to get her going again.

I think your car is the same as mine Chelle.. its Ok for two weeks then it cant be trusted !! I know someone else who had one and used to carry a booster Battery in the car . Nothing back from Lexus ... Luckily my present situation means the car gets used about twice a week when I do go away its only left for a few days and when I fly its left with valet parking so they have the problem of starting it !! I can live with it..

[supabil]

Alphacat ;Yes I do leave the battery fully connected with the intelligent charger supplying the charge constantly.The exercise is to supply the battery with replenishement power as it is used by the security system.

If you use an intelligent charger it will determine what current is being used and adjust accordingly.

The blocking diode in the alternator is not affected by overcharging as the charger senses when the battery is at full charge and stop charging when the current is used to a certain level it restarts charging repeating the cycle.

There are a lot of cars on the market that suffer from this phenomenom ,as most are used every day it does not become an issue but as a lot of Lexus cars are second cars used on lesser occasions ,this is one way to accomodate the issue.Just as a any problem as a solution there is a solution that creates another problem The security system is disabled as soon as you insert the ignition key into the lock or if it is card the same ,if you think your car is secure enough to leave either in situ when not attended it will solve the problem,but the cars insurance will be void.

Thanks for that. ...

Makes sense but I am not satisfied that a car with a perfectly good Battery should become unreliable after less than 2 months without having to charge the Battery in some way.

I often leave the country for weeks and when returning I expect the car to start if its been garaged indoors, at the airport, or with some car parking company and I wouldn't expect to have it started, I am surprised that members seem to accept this is 'normal'. It never was in the past and having security systems modern electronics etc it matters not the Battery should be able to cope if it meets its spec.

With that in mind I contacted Lexus.

At first I had some response from a woman who admitted she wasn't technical but suggested my Battery was at fault and I should take the car to a Lexus dealer. I wasn't happy with that and informed them that the Battery was fine I have done charge tests and drain tests etc My Battery is clean ( terminals and the casing) and I had heard from the lexus club web site that a number of people have this issue and in some cases have changed the Battery for anew one to no avail.

I also mentioned that if a car cant be left for about two months its not reliable and I believe this issue has been identified on the 430SC because so many of us use it infrequently..

I have just had an e-mail telling me the complaint has now gone to Lexus head office for customer service so I am hoping for something sensible back.

They should at least know why we have to trickle charge a good Battery after a few weeks. Bad design or whatever.

This was a £60000 car from a company that built a rep on reliability and quality. Plugging in little solar panels whenever you go on holiday and hoping it will start when you get back is not acceptable. My car was only 6 years old when I first realised what was happening and had only done 50000 miles.

Saying all that I haven't had the problem since last May when I was out the far east for 3 weeks it seems fine but I have used it at least once a week since.

I want to know from Lexus why? They must know....

Hi,

My wife has had trouble with her SC430 and Lexus has now replaced the Battery twice!! I am a retired Radio/Computer engineer and have now checked the current drain across the Battery with ignition off and all doors closed. The drain was just over 1.5AMPS!!!This means that after 10 hours the current drain is 15AMPS and after 100hours 4 days, the Battery will be flat. I removed the fuses 1 at a time and found only two which made much difference. The Radio 1 fuse was about 0.4AMP and the D/C Cut was 1.0AMP. What I need now is a sevice sheet for the electrics to further troubleshhot our problem. Incidentally, we akso have an 400h which has a current drain of only 0.4. Both our Lexus cars are due for a service on October 23rd, and I will be armed with a spanner and current multimeter to discuss this issue with one of the Technicians. I think that nominally, the drain is about 0.5AMP If I get any joy, I will post it later

Bil

Edited October 9, 2013 by IanS200
Added bil's post, as he reorted it by accident

[ColinBarber]

current drain should be much less than 0.5 Amps. Ideally less than 0.1 Amps after the vehicle has been shut off for 10 minutes or more.

[jeffreyt]

I think the Battery drain on mine must be similar to Bil's wife as my Battery goes flat in about 5 days without use.

I disconnect the Battery now whenever the car is not going to be used for a couple of days.Its a pain in the backside but easier for me than putting it on charge.

Lexus are never going to admit there is a problem so its unlikely any data sheets ( or whatever equivalent is in use these days)have been issued to the dealers on this subject so talking to them will be a waste of time which means its down to us to sort out the problem.

I shall be looking at this further over the winter and if I find anything of interest I will post it.

[alphacat]

Alphacat ;Yes I do leave the battery fully connected with the intelligent charger supplying the charge constantly.The exercise is to supply the battery with replenishement power as it is used by the security system.

If you use an intelligent charger it will determine what current is being used and adjust accordingly.

The blocking diode in the alternator is not affected by overcharging as the charger senses when the battery is at full charge and stop charging when the current is used to a certain level it restarts charging repeating the cycle.

There are a lot of cars on the market that suffer from this phenomenom ,as most are used every day it does not become an issue but as a lot of Lexus cars are second cars used on lesser occasions ,this is one way to accomodate the issue.Just as a any problem as a solution there is a solution that creates another problem The security system is disabled as soon as you insert the ignition key into the lock or if it is card the same ,if you think your car is secure enough to leave either in situ when not attended it will solve the problem,but the cars insurance will be void.

Thanks for that. ...

Makes sense but I am not satisfied that a car with a perfectly good Battery should become unreliable after less than 2 months without having to charge the Battery in some way.

I often leave the country for weeks and when returning I expect the car to start if its been garaged indoors, at the airport, or with some car parking company and I wouldn't expect to have it started, I am surprised that members seem to accept this is 'normal'. It never was in the past and having security systems modern electronics etc it matters not the Battery should be able to cope if it meets its spec.

With that in mind I contacted Lexus.

At first I had some response from a woman who admitted she wasn't technical but suggested my Battery was at fault and I should take the car to a Lexus dealer. I wasn't happy with that and informed them that the Battery was fine I have done charge tests and drain tests etc My Battery is clean ( terminals and the casing) and I had heard from the lexus club web site that a number of people have this issue and in some cases have changed the Battery for anew one to no avail.

I also mentioned that if a car cant be left for about two months its not reliable and I believe this issue has been identified on the 430SC because so many of us use it infrequently..

I have just had an e-mail telling me the complaint has now gone to Lexus head office for customer service so I am hoping for something sensible back.

They should at least know why we have to trickle charge a good Battery after a few weeks. Bad design or whatever.

This was a £60000 car from a company that built a rep on reliability and quality. Plugging in little solar panels whenever you go on holiday and hoping it will start when you get back is not acceptable. My car was only 6 years old when I first realised what was happening and had only done 50000 miles.

Saying all that I haven't had the problem since last May when I was out the far east for 3 weeks it seems fine but I have used it at least once a week since.

I want to know from Lexus why? They must know....

Hi,

My wife has had trouble with her SC430 and Lexus has now replaced the Battery twice!! I am a retired Radio/Computer engineer and have now checked the current drain across the Battery with ignition off and all doors closed. The drain was just over 1.5AMPS!!!This means that after 10 hours the current drain is 15AMPS and after 100hours 4 days, the Battery will be flat. I removed the fuses 1 at a time and found only two which made much difference. The Radio 1 fuse was about 0.4AMP and the D/C Cut was 1.0AMP. What I need now is a sevice sheet for the electrics to further troubleshhot our problem. Incidentally, we akso have an 400h which has a current drain of only 0.4. Both our Lexus cars are due for a service on October 23rd, and I will be armed with a spanner and current multimeter to discuss this issue with one of the Technicians. I think that nominally, the drain is about 0.5AMP If I get any joy, I will post it later

Bil

That's really bad isn't it ? When Lexus 'technicians' (used loosely) change the Battery twice, when the current is draining away like that! I really don't like letting them touch my car. I understood that an expected Battery drain on the 430SC would be about 0.08 amp after the car was stopped for about 15 minutes or so. I agree with Colin. I haven't had any problems with mine for some time now but I think its draining over about 8 days or so I only do runs of over about 20 miles usually so its manageable. but as has been said Lexus don't want to know.

[tomzarblue]

Hi, I was interested to read Supabils post as I have exactly the same problem with almost identical readings from the 2 fuses mentioned. Did you get an answer from the Tech on your service visit? Anyone have any thoughts? Ive read it may be the stereo amp.

[alphacat]

Hi, I was interested to read Supabils post as I have exactly the same problem with almost identical readings from the 2 fuses mentioned. Did you get an answer from the Tech on your service visit? Anyone have any thoughts? Ive read it may be the stereo amp.

I was reading some of the US 430sc forms and some posts on there seemed to identify the stereo amp too.. It seems these cost around $2500 to replace but the old one can be refurbished..I believe there is a

place in the UK that does this.

[shaun.reinson]

I bought a refurbished amp from the US via eBay - paid about £300 for it.

Much cheaper than the £1700 Lexus UK wanted for a new one.

As they're so rare in the UK, its unlikely you'll be able to pick up a second-hand one here TBH.

During the first year or two of manufacture, the amps were a little flaky and many went back (to Mark Levinson) for repair and these will have a sticker on them indicating this.

If you buy an old one, look for the sticker.

Repair in the UK will cost around £150 to £300 - but depends on them have an exchange unit in stock - which is the usual way they operate.

[alphacat]

I bought a refurbished amp from the US via ebay - paid about £300 for it.

Much cheaper than the £1700 Lexus UK wanted for a new one.

As they're so rare in the UK, its unlikely you'll be able to pick up a second-hand one here TBH.

During the first year or two of manufacture, the amps were a little flaky and many went back (to Mark Levinson) for repair and these will have a sticker on them indicating this.

If you buy an old one, look for the sticker.

Repair in the UK will cost around £150 to £300 - but depends on them have an exchange unit in stock - which is the usual way they operate.

Have you got the suppliers contact / That's a big saving on new.

[shaun.reinson]

The seller on eBay was 'junebug_50' and was (probably) a private purchase back in August 2011

I scoured eBay until one came up at a price I was okay with - so its a combination of patience and luck...

As it was an import from the US it was subject to some UK import tax before the post office would release it - but still cheap in comparison etc...

[alphacat]

The seller on ebay was 'junebug_50' and was (probably) a private purchase back in August 2011

I scoured ebay until one came up at a price I was okay with - so its a combination of patience and luck...

As it was an import from the US it was subject to some UK import tax before the post office would release it - but still cheap in comparison etc...

Thanks for that

[supabil]

Regarding my original Contact (#38). The Battery drain has now been solved and fixed. Armed with the information that the drain was in the circuit with a fuse of 'DC CUT' Lexus Milton Keynes were charged with finding the fault in no more that 2 hours. This they did and found a non-factory fitted box and wiring! At first it was thought to be an 'ELECTRONIC TRACKER' Fitted by the previous owner. However, this was far from the truth. It was an item manufactured by a company called Impact Secure and is usually used on lorries. Via radio the control box can disable the car, start the alarm, lock/unlock the doors and to the boot etc. The driver can have his own transmitter, or it can be done remotely!. To remove this item and all it's associated wiring took all day! Bless them Lexus MK only charged us the 2 hours. (How's that for Customer Service!). There were several fuses, two Ariel's, plugs and a whole heap of wiring. (See attachment enclosed). The drain has dropped from 1.5amps to about 0.29amps. Over Christmas, the car wasn't run for 8 days. When tried it fired up immediately. This problem has been with us for 51/2 years, so I suggest that if you bought your car second hand and you have a similar drain on that circuit, don't rule out the possibility of a non-Lexus addition. Regards Bil Levinson

[Paul_G]

Wow....good result!

[alphacat]

Regarding my original Contact (#38). The battery drain has now been solved and fixed. Armed with the information that the drain was in the circuit with a fuse of 'DC CUT' Lexus Milton Keynes were charged with finding the fault in no more that 2 hours. This they did and found a non-factory fitted box and wiring! At first it was thought to be an 'ELECTRONIC TRACKER' Fitted by the previous owner. However, this was far from the truth. It was an item manufactured by a company called Impact Secure and is usually used on lorries. Via radio the control box can disable the car, start the alarm, lock/unlock the doors and to the boot etc. The driver can have his own transmitter, or it can be done remotely!. To remove this item and all it's associated wiring took all day! Bless them Lexus MK only charged us the 2 hours. (How's that for Customer Service!). There were several fuses, two Ariel's, plugs and a whole heap of wiring. (See attachment enclosed). The drain has dropped from 1.5amps to about 0.29amps. Over Christmas, the car wasn't run for 8 days. When tried it fired up immediately. This problem has been with us for 51/2 years, so I suggest that if you bought your car second hand and you have a similar drain on that circuit, don't rule out the possibility of a non-Lexus addition. Regards Bil Levinson

That is interesting... but I cant see why it took 2 hours. Just take a fuse out or cut a wire !!