12v Battery, the Achilles heel

[ColinBarber]

9 minutes ago, mujib1 said:

Would like some clarification if anyone can help advise please. i have a flat battery, no electrics etc. I am thinking about getting a NOCO GENIUS5UK Smart Battery Charger. Cannot leave it charging overnight as car on road outside home. Will this devise be OK to in effect charge for a short while to get car started so I can keep running for 60 mins etc?

Also, does this(NOCO charger terminals) connect to battery in boot on IS300H and not under the hood? Would jump starting my car using another car need connecting under the hood (that's what it says in my manual). Just a bit confused about the terminals between hood and boot where I see the 12V battery.

Yes, the charger would probably take around 8 hours to complete charge a flat Battery but if you can charge it for a couple of hours you should have enough charge to get the vehicle into Ready mode.

You can connect to either the points in the engine bay or directly to the Battery in the boot - makes no difference.

Obviously you could take the Battery completely out of the vehicle and charge indoors. That might be the best thing to do if your Battery is completely flat. Let the charger fully charge the Battery and then use the repair mode to help restore any capacity that has been lost because of it sitting in a discharged state.

[200h]

on the IS300h use the key hole in the boot lid to get to the 12v Battery & hook up

another Battery to the car & get yourself into ready mode straight away then

go for a drive

[mujib1]

7 minutes ago, 200h said:

on the IS300h use the key hole in the boot lid to get to the 12v battery & hook up

another battery to the car & get yourself into ready mode straight away then

go for a drive

Thanks Colin and Mark. Will give that a try in the morning. Even the manual key is not opening the driver door so I cannot get to the bonnet/hood  - is it meant to be like that? Could be frozen lock etc

Have managed to open the boot with the manual key though (first time I have done that, was not aware the key slot was there until Mark mentioned it!)

Glad to hear it will make no difference which terminals I connect donor car to (under bonnet or back in the boot).

Thanks again!

 

[200h]

its well hidden

[ColinBarber]

19 minutes ago, mujib1 said:

Even the manual key is not opening the driver door so I cannot get to the bonnet/hood  - is it meant to be like that? Could be frozen lock etc

It can become very stiff

[Brechin Slate]

16 hours ago, ColinBarber said:

It can become very stiff

[Bootleg]

I've had my IS300h more in lockdown than not. I did a significant amount of research beforehand, including this site, read as much of the manual as I could, plus my brother has had an RX450h for 13 years, yet my first call to roadside assistance was for a flat aux Battery, just before lockdown. It was the first time I was aware of the aux battery. The Battery and any drain problems have been checked out twice by Lexus as ok. I need to know enough to get the best out of any machine I buy, but this has really put a downer on owning what I thought was the most reliable car on the market. I've got a booster pack, etc, but every time I go to start it up, I wonder, and that lack of confidence really takes the shine of what I think is an otherwise excellent car. Lockdown has exacerbated this weakness into its Achilles Heel. If asked what I think about owning a Lexus hybrid I will always mention this fact. Most of my street are familiar with me having the bonnet up or my head in the boot as they drive away in their Audis, BMWs and Mercs.

[200h]

in the garage i have a spare car Battery i bought it a few years ago

with my Battery going flat as i hadn't used the car for 3 - 4 weeks

during winter, if i wasnt using my car daily now i think i would hook up

my spare Battery to the Aux Battery to keep it topped up and ready to go.

i bought the cheapest Battery the store had as i only wanted to be able

to power the car into ready mode.

[Herbie]

1 hour ago, Bootleg said:

I need to know enough to get the best out of any machine I buy, but this has really put a downer on owning what I thought was the most reliable car on the market. I've got a booster pack, etc, but every time I go to start it up, I wonder, and that lack of confidence really takes the shine of what I think is an otherwise excellent car.

Respectfully, I think you're making a mountain out of a molehill.

Any Battery on any car, if left for long enough will go flat, whether that's a Lexus, Ford, Kia or whatever.

Toyota/Lexus made a bit of a mistake by only using small-capacity batteries and not putting it in the owners manual what the possible consequences might be. You know about it now so you can deal with it appropriately.

If you feel embarrassed by always having the bonnet/boot up then either use the car more or follow Toyota's advice to put the car in READY and Park for 60 minutes a week. Alternatively, keep it connected to a trickle charger or do as I did and install an easy access jump start socket somewhere in the cabin so that you can sit in the driver's seat while you use the jump start pack and don't need to go into either boot or bonnet.

I know and understand that it's not an ideal situation and not what should be expected of a luxury brand, especially when a car can cost north of £60k, but it's a fact we have to live with and if that's all that's wrong with the car then I don't mind putting up with it.

[Brechin Slate]

16 hours ago, Herbie said:

do as I did and install an easy access jump start socket somewhere in the cabin so that you can sit in the driver's seat while you use the jump start pack and don't need to go into either boot or bonnet.

Have you got a photo/drawing/procedure for this set up Hebs?

[Herbie]

3 hours ago, Brechin Slate said:

Have you got a photo/drawing/procedure for this set up Hebs?

Mine's an RX so you'll have to adapt the process for your own car, but I'm sure you'll find a suitable location to site the socket:

 

 

[Brechin Slate]

2 hours ago, Herbie said:

Mine's an RX so you'll have to adapt the process for your own car, but I'm sure you'll find a suitable location to site the socket:

 

 

Excellent, Herbs, thanks.

[Herbie]

You're welcome Mike

[Alex34]

New owner to the IS300h (pre-owned) for about three weeks now. With all the good weather I decided to do an interior detail myself. To make a long story short, I ended up draining the Battery and had to call assistance out (forgot my starter pack at work).

These aux batteries definitely do drain quickly. To be fair though, I still haven't gotten use to the car and probably had it in the wrong mode with the doors open or something. The AA guy certainly had a laugh. Says it happens all the time and that Lexus call outs are usually the quickest and least involved. 

In the future, is there anything I should do to prevent this happening again when detailing the interior?

[ColinBarber]

Just now, Alex34 said:

In the future, is there anything I should do to prevent this happening again when detailing the interior?

Turn off the interior light. If you a listening to the stereo, or using the 12v cig lighter output then made sure the vehicle is in Ready mode and not just with the ignition turned on. In Ready mode the engine will start, but will switch off again once up to temp and then cut in and out as the hybrid Battery charge gets too low.

[Brechin Slate]

49 minutes ago, Alex34 said:

I ended up draining the battery

Did exactly the same thing myself a few weeks ago, you live and learn!  See the very beginning of this thread, link below: