12 volt battery

[Booler1949]

I recently bought a UX and the 12 volt Battery went flat , l was faffing about with the settings in "accessory mode" and the Battery.  Luckily l was on my drive . Called Lexus recovery, which is the AA by the wsy 😀 .

He said always have the car in ready mode when looking at the settings because the 12 volt Battery is very small .

 

Anyway he recommended a small jump pack as has already been mentioned  . Maybe Santa will bring me one .😂

Thanks Robert 

[iainmangle]

Exactly the same this end. AA came out twice in a short space of time and condemned the Battery on the second visit, but Lexus wouldn't even inspect it for four weeks. It is booked in for next week but I doubt they will agree with the AA. In the meanwhile I have jump started three times, including once in a supermarket car park,  and 24 hour charged once. I got a jump kit from amazon for about £35 and it works well - shouldn't have to on a 6 month old £40k car though! Too many instances reported for this to be idiot drivers, as some suggest. 

[Chas G]

Apologies for perhaps  being impertinent but Lbx owners would do well to log on to the Toyota owners forum Yaris section where owners have been going through exactly the same flat 12 volt Battery issues for years. There is a pinned thread where you will find a variety of solutions and you just pick whichever you will find the most convenient.

[Lbeex]

12 hours ago, iainmangle said:

...but Lexus wouldn't even inspect it for four weeks. It is booked in for next week but I doubt they will agree with the AA. In the meanwhile I have jump started three times, including once in a supermarket car park,  and 24 hour charged once. I got a jump kit from Amazon for about £35 and it works well

Ask Lexus to charge your car 12V Battery to 100% capacity, and then after at least one hour later let them measure voltage - it should be 12.6 - 12.7V. If not Battery is to be replaced at warranty conditions.

[Lbeex]

On 10/29/2024 at 9:04 AM, Don C said:

It isn’t an AGM battery, it’s a conventional lead acid.  

I can assure you that you can charge the battery from the jump start terminal.  I don’t know why they would say otherwise other than a lack of understanding on their part.  It’s just an extension wire from the battery.  I leave mine on a smart charger while I’m away and I can monitor the charge rate via the smart plug from another country.  

Ok, then I am going to verify it by measuring charge current and voltage.

Anyway, trickle charger is not an option for me because I am simply ashamed that my new Lexus in underground parking has these wires going under the engine hood, unlike most of other cars around.

I would use it in my second location in the countryside only, maybe.

Jump starting - really efficient and fast recovery, but... :

The booster(usually LiPo or better LiFePo4)  should not be exposed to temperature above 75degC (in extreme cases fire hazard), so this is risky to keep the booster in the car, unless in winter.

Keeping a booster in the car? OK but where?

·        Trunk:  If 12V Battery is flat you can’t open the trunk. You can access the car from driver door side manually but can you open the trunk  before using the booster – probably not (not sure).

·        Inside: LBX storage compartments are rather small.

Any ideas?

 

[Herbie]

1 hour ago, Lbeex said:

Any ideas?

When I had my 3RX I installed a jump start socket in the centre console and kept the Battery pack itself in either the glove box or under a seat, and had no problems regarding heat in the cabin at all.

 

[iainmangle]

Which is a sensible thing to do,  but should be so unnecessary in 2024. especially with a manufacturer who claims to be so innovative. 

 

[iainmangle]

12 hours ago, Lbeex said:

Ask Lexus to charge your car 12V battery to 100% capacity, and then after at least one hour later let them measure voltage - it should be 12.6 - 12.7V. If not battery is to be replaced at warranty conditions.

Pretty sure that is what they intend to do as I have to leave it with them all day. I fully expect them to give it a clean bill of health though, and I'll be jump starting again within a couple of weeks.

[Geotechnic]

Having read the posts for the LBX and the Toyota equivalent I purchased a jump pack before I got the car, sits quite happily under the passenger seat (can't imagine that's going to get hotter than 75 degrees C) As yet have had no starting issues, using the car two to three times a week, less than 100 miles of travel. Given the problems others have reported I've been checking the 12v Battery voltage with a multimeter at the Battery, with the car open but off, the Battery has been reading 12.4v to 12.6v. I'm assuming the very act of unlocking the car will cause some systems to switch on so not expecting it to show fully charged, 12.7v-12.8v. The lower 12.4v was after three days sitting on the drive unused. I am waiting on the arrival of a Bluetooth Battery monitor to fit directly to the battery(eBay £20) so I can monitor the Battery when the car is locked. Wonder if anybody has checked the Battery voltage on a non-starting car before jumping it to see how low it was?

[iainmangle]

A bit sad isn't it, that in 2024 we are having to take such measures to ensure we can get into, and start, a £40k car! I have the jump kit as I had no choice after it failed twice, but not sure I will invest in anything else before I sell the car.

[Herbie]

5 hours ago, iainmangle said:

A bit sad isn't it, that in 2024 we are having to take such measures to ensure we can get into, and start, a £40k car! I have the jump kit as I had no choice after it failed twice, but not sure I will invest in anything else before I sell the car.

Sadly, it is what it is and Lexus aren't going to do anything about it. It's not ideal but the fact is you know about it now and can take steps to mitigate the situation.

I think we've come full circle now though, haven't we, regarding prospective owners doing some research to see if a hybrid fits their needs and driving habits before signing on the dotted line?

If you knew then what you know now, would you still buy the car? Genuine question, not trying to be obnoxious, just curious.

[Fredcl]

1 hour ago, Herbie said:

Sadly, it is what it is and Lexus aren't going to do anything about it. It's not ideal but the fact is you know about it now and can take steps to mitigate the situation.

I think we've come full circle now though, haven't we, regarding prospective owners doing some research to see if a hybrid fits their needs and driving habits before signing on the dotted line?

If you knew then what you know now, would you still buy the car? Genuine question, not trying to be obnoxious, just curious.

 

Yes, agree we can stop discussing because that brings no new information to the table.

My two cents in respect to your question of buying decision.
It's still a nice driving car but I would be hesitant for buying the LBX if I knew upfront. Most propably would have a closer look to hybrid cars which already have a solution for this "feature".
But again it would be a minus on my wife's and my checklist which we used before buying.

[Don C]

I know some of you will argue that you shouldn’t have to do it but I fitted an upgraded Battery on my mate’s LBX today.  You don’t have to do it, it’s up to you but you can see the capacity is well up.  It’s under the back seat, took me about 20 minutes and it cost just over £71 with a 5 year warranty.  

[iainmangle]

31 minutes ago, Fredcl said:

 

Yes, agree we can stop discussing because that brings no new information to the table.

My two cents in respect to your question of buying decision.
It's still a nice driving car but I would be hesitant for buying the LBX if I knew upfront. Most propably would have a closer look to hybrid cars which already have a solution for this "feature".
But again it would be a minus on my wife's and my checklist which we used before buying.

For me it is not my first hybrid, or EV, so it really it isn't a generic hybrid problem. If other manufacturers can sort it; if after market upgrades can sort it; then it is a Lexus problem and they will only listen if people make a noise. If you don't want to read the posts,  or contribute, then you have the option of scrolling. 

[Herbie]

44 minutes ago, Don C said:

I know some of you will argue that you shouldn’t have to do it but I fitted an upgraded battery on my mate’s LBX today.  You don’t have to do it, it’s up to you but you can see the capacity is well up.  It’s under the back seat, took me about 20 minutes and it cost just over £71 with a 5 year warranty.  

Well done Don. The usual problem is getting something that physically fits in the Battery box and has the terminals the right way round.

I take it that the one on the right is the original at 35Ah and you've upgraded to 45Ah? If so, that gives you an extra 5.92 days (from 20.83 days @35Ah to 26.75 days @45Ah) before it goes flat if not used or charged - caveats further up this thread still apply though.

How I wish we could get something with an absolute minimum of 75Ah or better still, 100Ah. Sadly, nothing like that will ever fit in the Battery box of my RX so I've got my trusty jump start Battery pack in the car at all times.

[Herbie]

1 hour ago, iainmangle said:

If other manufacturers can sort it; if after market upgrades can sort it; then it is a Lexus problem

Look, once and for all, it's not a Lexus (or other manufacturer) problem, it's a matter of simple physics, and no matter how much you may want to, not even you can defeat the laws of physics.

Small batteries don't hold charge for long. Larger batteries hold charge for longer.

Lexus made a decision a long time ago to use small batteries and it really is as simple as that. They could change their rationale and make future cars with bigger batteries but (a) I very much doubt they will, and (b) that wouldn't help the owners of thousands of cars driving around now.