Battery issues

Ben1001 · September 9, 2017

Bought a Gen 3 2014 IS250 in January from Lexus. Covered 15k miles. In its 3rd year it only covered a few hundred miles, was probably sat around a lot and Battery left to run flat.

No issues with daily use for months then our baby was due so I didn't use it much for 3 weeks, hadn't started it in a week and it was flat.

Have used it regularly since, no issues. It went in for a service this week and the notes say - "slow Battery recharge". Need to call them on Monday to find out.

Should this be covered under warranty or at least good will, I reported the issue to them when it happened in June but never heard back, despite Lexus UK saying they would arrange a free health check.

200h · September 9, 2017

i had the flat Battery issue in jan this year after we had a baby over christmas time.

it took me by surprise when i tried to start the car and all the dash started to flash

, needles started to flick and since there was little power in the Battery i couldn't turn it off either.

my car has been serviced this year and i haven't been told they have found any problems like yours.

Bluesman · September 9, 2017

4 minutes ago, 200h said:

i had the flat battery issue in jan this year after we had a baby over christmas time.

it took me by surprise when i tried to start the car and all the dash started to flash

, needles started to flick and since there was little power in the battery i couldn't turn it off either.

my car has been serviced this year and i haven't been told they have found any problems like yours.

Made a change from a Turkey. Sorry, couldn't resist it. I have along with many others especially with LS400 have suffered the flat Battery syndrome and when recharged happily carries on for months/years.

Martin F · September 10, 2017

I'd been having an issue on the Battery with my IS300h for quite a while, started off that if I left the car for any longer than three weeks I would need to charge it, then two weeks and then a week. I asked Lexus to look at it when it went in for service back in April and after checking it over night they swapped it under warranty.

As you bought your car from Lexus in January then the issue should be covered under warranty as long as they test and confirm the fault.

200h · September 10, 2017

the batteries are really expensive i have found them on the internet for £250'ish price range

this isnt a genuine oem Battery either ,so i agree with martin get it replaced under warranty if its needed.

Ben1001 · September 10, 2017

Really, I have the 250 so it seems to be a £60 part as there's none of the start/stop rubbish on this model which require special batteries.

8 hours ago, 200h said:

the batteries are really expensive i have found them on the internet for £250'ish price range

this isnt a genuine oem battery either ,so i agree with martin get it replaced under warranty if its needed.

Will be calling tomorrow to see what they say.

200h · September 10, 2017

sorry Ben for alarming you

i thought you had a IS hybrid my mistake

i read the Battery going flat part which is the same as me and assumed your car was a 300h

Ben1001 · September 11, 2017

Called Lexus this morning, they said the Battery was tested and is fine, it was just low when they checked it and they put it on charge. They say the cars electrics were tested and are also fine (no drain, alternator working correctly).

Doesnt make any sense to me, I had driven the car 3000 in the past month so it's had daily use and some really long runs. I think there is still a fault but I can't prove it. May try and leave it for 10 days while I'm off work next week and see if it runs flat (like it did last time).

Any ideas what else it could be?

rayaans · September 11, 2017

4 minutes ago, Ben1001 said:

Called Lexus this morning, they said the battery was tested and is fine, it was just low when they checked it and they put it on charge. They say the cars electrics were tested and are also fine (no drain, alternator working correctly).

Doesnt make any sense to me, I had driven the car 3000 in the past month so it's had daily use and some really long runs. I think there is still a fault but I can't prove it. May try and leave it for 10 days while I'm off work next week and see if it runs flat (like it did last time).

Any ideas what else it could be?

I recall the terminals can be loose on the cars. Worth checking that out first. Battery may be fine but if terminals are loose, then it could cause the issues you're having

BigChange · September 11, 2017

Agree with rayaans. I've experienced the result of a loose Battery connection and also, at a different time, a Battery shorting out. Both caused the Battery to run flat. Not a Lexus I hasten to add.

stevet · September 11, 2017

Agree with rayaans. I've experienced the result of a loose battery connection and also, at a different time, a battery shorting out. Both caused the battery to run flat. Not a Lexus I hasten to add.

I had loose Battery terminals on the ISF and that caused similar problems.

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Ben1001 · September 21, 2017

Flat Battery again! I've played my face to the garage and complained, having reported the issue previously and being fobbed off this is unacceptable.

Lexus tested the Battery (fully... finally) and found it wasn't holding the correct voltage (12.2v) New car Battery supplied free of charge after playing my face :)

Car is 3.5 years old but I'm aware it has little use in its second year as the owner lived abroad. Always suspected the Battery was the issue.

An.d.erson · January 3, 2020

I purchased a new UX 250 Sport in November 2019 .Mileage so far 870 miles

Tried to start 2nd Jan 2020 no electrical power from 12volt Battery

AA man arrived and started car using Battery

Called into Lexus garage checked car and Battery no fault found

this Is very worrying

Herbie · January 3, 2020

How long was it left standing and not used?

Lexus only fit small capacity batteries in their hybrids and it's not unusual for someone to park up at the airport for a two-week holiday and come back to a flat Battery.

The starter motor of a normal car will draw more than 300A as it cranks the engine to start it, so the Battery has to be big and beefy to supply that current. As you'll see from the photo below, my RX450h only draws 15.32A to boot the computers and get the car into the READY state, so they save a bit of money by only using small capacity 12V batteries in them.

The best way to deal with the possibility of a flat 12V Battery is to carry one of these battery packs in the glove box or the boot. They are superb, work really well, and eliminate the need for an AA man or a donor car.

mikejt · January 4, 2020

I've just had similar prob with IS300h Fsport. Needed new 12v Battery. I've had car just over year, done 10k motorway miles, however previous miles was 8k over 3yrs so I guess 12v Battery didn't get enough charge and now car can be parked for 2wks regularly. Lexus recommend about 12.5v with normal use but Yuasa who make this Battery tell me that this is only 60-65% charge and should be looking at 12.8v. I bought a Ctek msa 5.0 smart charger and using this regularly with their LED comfort lead which is permanently connected for quick checking. Its 45Ah AGM batt btw. but thats fully charged so I'm in email correspondence with Yuasa and Lexus to dig into this a bit. Be good to have more info on your Battery pack.

Herbie · January 4, 2020

7 hours ago, mikejt said:

Lexus recommend about 12.5v with normal use but Yuasa who make this battery tell me that this is only 60-65% charge and should be looking at 12.8v.

Here you go:

MONTIMAR · January 4, 2020

My car is only used every couple of weeks and about 5000 miles a year so to avoid any problems I connect a smart charger every couple of months to keep the Battery topped up and never have any issues. I live abroad during the Winter and leave the smart charger connected for 3 months without any problems.

royoftherovers · January 4, 2020

8 minutes ago, MONTIMAR said:

My car is only used every couple of weeks and about 5000 miles a year so to avoid any problems I connect a smart charger every couple of months to keep the battery topped up and never have any issues. I live abroad during the Winter and leave the smart charger connected for 3 months without any problems.

Stephen, what is your smart charger please?

MONTIMAR · January 4, 2020

I use a CTeck smart charger. It is the one recommended by Honest John. I connect it to the 12 volt charging point under the bonnet so nice and easy. I just leave it over night for a top up conditioning charge or 3 months during the Winter when I'm away. Never had an issue with the charger or the Battery over the past 3 years.

malcolmw · January 4, 2020

Just to support the use of mains chargers, I used to have an Aston DB9 which I only used for pleasure and only did 20K miles in the 12.5 years I had it. I always put it on trickle charge in the garage when not in use and when I sold it it still had the original Battery. Undercharge is your enemy, not overcharging.