Flat battery

[Razor120]

Hi Everyone

I have a UX250H E-four during the pandemic i have not been using the car much, basically about 10 miles a week just to do the weekly shopping. Earlier this week I had to call out the AA who confirmed the 12v Battery was flat. He jump started the car and i went for a 60 min drive. Ive read that the ux will recharge the Battery if you put it in ready mode for about 60 mins is this true?

Also has anyone purchased a jump starter booster and if so can they recommend any.

Cheers Ray

[royoftherovers]

Hello and welcome Ray.

Yes and Yes and see https://www.amazon.co.uk/BIUBLE-Portable-Starter-Battery-Intelligent/dp/B08FMSNZJJ/ref=sr_1_10?crid=3U53KO9CSHOY1&dchild=1&keywords=jump+starter+power+pack&qid=1605213713&sprefix=jump+starter%2Caps%2C365&sr=8-10

[Razor120]

Thanks John.  Have you used such a booster? Was deffo looking to get one but need to make sure it would work. I know you have to earth the negative terminal and the leads don't look that long (unlike the one the AA had, but that looked much bigger).

[royoftherovers]

3 minutes ago, Razor120 said:

Thanks John.  Have you used such a booster? Was deffo looking to get one but need to make sure it would work. I know you have to earth the negative terminal and the leads don't look that long (unlike the one the AA had, but that looked much bigger).

I have bought 2 but not had to use either yet.

You will connect it to the Battery Terminals in the Boot.If you look closely at the link I gave you, you will see that there is no need to earth the negative terminal.Have a close look.

[Razor120]

The booster was connect from the + terminal under the bonnet and then earthed - the AA guy said thats' how you jump start it and you do not connect it to the 12v Battery in the boot.

 

[Razor120]

this is what i found for jump starting a UX 

 

[Herbie]

1 hour ago, Razor120 said:

The booster was connect from the + terminal under the bonnet and then earthed - the AA guy said thats' how you jump start it and you do not connect it to the 12v battery in the boot.

To quote from a post I made just a couple of days ago in a different thread that seems to apply partially to your case:

I speak not as a Lexus technician or design engineer, nor in any official capacity whatsoever, but rather as a fully qualified, time-served electrician who, since completing my apprenticeship in 1978, has worked mostly in the maintenance and installation fields of both domestic and industrial electrics; spent most of my working career as a telephone engineer (cable jointer) on BT; and latterly self-employed doing computer repairs and bespoke builds, and whose hobbies include amateur radio (callsign G7IFM).

In other words, most of my life has been spent dealing with electrical and electronics systems.

I mean no disrespect to anyone but I really do think that a lot of people get hung up on this and overthink it to the nth degree, whereas it's really very simple.

12 Volts DC is 12 Volts DC in the UK, the USA, India, China and so on.

12 Volts DC is 12 Volts DC both at the back of the car (if the Battery is in the boot) and also at the front of the car if you want to utilise the dedicated jump start post.

12 Volts DC is 12 Volts DC whether it comes from the car Battery or a Battery charger, or a trickle charger, or the car's own alternator or DC/DC converter.

Jump leads or jump start Battery packs can be used at the front or the back of the car because all you are doing is supplementing one dodgy 12 Volt source by piggybacking a good 12 Volt source onto it.

Trickle chargers can be connected to the Battery whilst it is still connected to the car. The clue is in the name, ie, trickle charger. It only supplies enough current to overcome the quiescent current draw of things like the clock, the radio presets, the alarm etc., and also the self-discharge rate of the Battery. Add all that up and it comes to far less than the Battery itself can supply so, in and of itself, a trickle charger cannot do any harm unless - and this is very important - it goes faulty in some way.

I would imagine that most, if not all trickle chargers, will have some sort of fail-safe mechanism to avoid any damage either to itself or to the car, but if something goes wrong I can take no responsibility - you do this at your own risk.

*****************************************

And just to add a further point, I do indeed have a very similar unit to the one John linked to above and they work brilliantly. I've not had to use it on my own car yet but I have started three or four 'conventional' cars for other people and it has always worked first time.

I don't like getting cold and wet (Sod's Law usually dictates that it has to be bad weather when a Battery fails ) so I decided to install a 'comfort' jump start point in the cabin of my RX450h:

 

 

[Herbie]

1 hour ago, Razor120 said:

I know you have to earth the negative terminal and the leads don't look that long (unlike the one the AA had, but that looked much bigger).

 

1 hour ago, royoftherovers said:

You will connect it to the Battery Terminals in the Boot.If you look closely at the link I gave you, you will see that there is no need to earth the negative terminal.Have a close look.

The negative terminal (of the battery) is the earth and is connected to the entire car body, so the negative terminal of any jump leads or jump start pack can be either connected directly to the negative Battery post* or any bare metal, screw, nut or bolt, either at the front or the back of the car.

*The usual advice to connect the negative jump lead to some random bare metal away from the Battery itself is to avoid any sparks igniting the hydrogen gas given off from the Battery and has nothing whatsoever to do with the electrical operation of jump starting.

Having said that, I have never seen, nor ever heard of, and don't know of anyone who ever has seen or heard of any explosion ocurring in more than 40 years of motoring and spannering. I'm not saying it can't happen, just that it seems to be a very unlikely event.

[Razor120]

I was referring to the youtube video I posted and this is how the AA guy started my car. 

[ALAW]

From page 459 of the UX manual.

●If recharging with the 12-volt Battery installed on the vehicle, be sure to disconnect the ground cable

 

[ALAW]

For Jump starts refer to page 544 of the UX manual

 

[Navnan2]

Do people still think a UX hybrid is no worse regards Battery resilience if the car isn't used regularly than a conventional petrol or diesel. I would like to be reassured given recent postings on the subject. My neighbour who has a Mitsubishi 4 wheel drive hybrid has had the AA out because he left his tail gate open for an extended period so the courtesy lights stayed on and the Battery became flat. The AA guy said his vehicle had a smaller Battery than conventional vehicles for ancillary components including starting off which explained the short life.

[royoftherovers]

12 hours ago, ALAW said:

For Jump starts refer to page 544 of the UX manual

 

You are a shining light Brent.

[Herbie]

20 minutes ago, Navnan2 said:

Do people still think a UX hybrid is no worse regards battery resilience if the car isn't used regularly than a conventional petrol or diesel.

All hybrids (or at least those from the Toyota/Lexus stable) suffer in the same way but it isn't a fault or a problem, it's by design.

A conventional car has a starter motor that will pull more than 300A from the Battery when cranking the engine so the Battery has to be big and beefy to supply that.

A hybrid doesn't have a conventional starter motor and it only takes 20A or less to 'start' the car, ie, boot the computers, pressurise the brakes and get the hybrid system into READY mode.

Given that, it's obvious that the 12V Battery doesn't have to be as big and beefy as in a conventional car, and this benefits the manufacturer in two ways:

1. Smaller Battery doesn't cost as much so there are cost savings there.
2. Smaller Battery weighs less, so helps in keeping the whole vehicle weight down, which helps to cut fuel consumption and helps to keep emissions down to meet the ever-lowering targets imposed by various governments.

It doesn't matter to us as the owner of a single car but when multiplied up to hundreds of thousands you begin to see the logic of the manufacturer's decisions.

The only downside for us as the owners is that a smaller Battery goes flat more quickly than a larger one does, so we either have to use the car more to keep that 12V Battery charged up or connect it to a trickle charger, or be prepared with jump leads or a jump start Battery pack.

[Herbie]

13 hours ago, ALAW said:

From page 459 of the UX manual.

●If recharging with the 12-volt battery installed on the vehicle, be sure to disconnect the ground cable

 

Technically that is correct but it's written into the manual for one reason and one reason only, which is to cover themselves if someone is using an old, unregulated charger that's been covered in dust and spider webs at the back of the garage for the last 40-odd years and which anyone with a modicum of commonsense would not even contemplate using on a modern car filled with complex electronics.

A more appropriate instruction would be If recharging with the 12-volt Battery installed on the vehicle, do not use an old, unregulated charger. Only use an intelligent charger with a clean and regulated output.

This is because the output of old chargers is often 'dirty' with the voltage itself fluctuating (often wildly) and not a true DC waveform.

[ColinBarber]

8 hours ago, Herbie said:

A more appropriate instruction would be If recharging with the 12-volt battery installed on the vehicle, do not use an old, unregulated charger. Only use an intelligent charger with a clean and regulated output.

The owner could still accidentally switch the charger to 24v mode, if it has one, which is another reason why they cover themselves by stating you need to disconnect the vehicle. Even using a desulphation or repair mode which outputs close to 16v isn't desirable, although it is unlikely to cause an issue with Toyota electronics.

[PCM]

On 11/12/2020 at 8:43 PM, royoftherovers said:

Hello and welcome Ray.

Yes and Yes and see https://www.amazon.co.uk/BIUBLE-Portable-Starter-Battery-Intelligent/dp/B08FMSNZJJ/ref=sr_1_10?crid=3U53KO9CSHOY1&dchild=1&keywords=jump+starter+power+pack&qid=1605213713&sprefix=jump+starter%2Caps%2C365&sr=8-10

Daughter's car would not start this morning - totally dead.

Took out my trusty portable starter and started it. ( Had to use its force-start feature. )

Brilliant.

Top tip - keep it charged and in your car, not the boot. Boot would not unlock with a dead Battery.

[royoftherovers]

Key will open Boot Piers.

[Herbie]

1 hour ago, royoftherovers said:

Key will open Boot Piers.

Depends which car his daughter has John.

If I remember correctly our 2005 RX300 had a key barrel in the tailgate but our 2013 RX450h doesn't.

[PCM]

Just now, Herbie said:

Depends which car his daughter has John.

If I remember correctly our 2005 RX300 had a key barrel in the tailgate but our 2013 RX450h doesn't.

( A Toyota Aygo! )

[royoftherovers]

3 minutes ago, Herbie said:

Depends which car his daughter has John.

If I remember correctly our 2005 RX300 had a key barrel in the tailgate but our 2013 RX450h doesn't.

Many thanks Herbie. I should realise by now that the most obvious solution does not always work !

[royoftherovers]

4 minutes ago, PCM said:

( A Toyota Aygo! )

So, was I right or wrong in this instance Piers?

[PCM]

1 minute ago, royoftherovers said:

So, was I right or wrong in this instance Piers?

Not sure - rain stopped play - will have to check when it's dry outside.