Flat battery-happy birthday.

Wallace · April 27, 2020

Ordinarily on my birthday I would be off to the local for a pint or three, but not today as the Lexus won't start because the Battery is flat. So I have spent a couple of hours trying to find a replacement, but with no luck. Has anyone actually found a direct replacement?☹️

jumbojake · April 27, 2020

I had the same with our Rx450h... I found the batteries are very hard to find equivalents, mostly because non standard sizes, plus they need extra specifications to live inside the car, as opposed to behind the firewall.

As a result I ended up going to Lexus (lexus parts direct) .. about 2x what I wanted to pay, but piece of mind it will not only fit, but also safe in an accident, if I am ever rear ended

Herbie · April 27, 2020

51 minutes ago, Wallace said:

Ordinarily on my birthday I would be off to the local for a pint or three, but not today as the Lexus won't start because the battery is flat. So I have spent a couple of hours trying to find a replacement, but with no luck.

I'm assuming you've tried charging it first before looking for a replacement?

Wallace · April 27, 2020

9 minutes ago, Herbie said:

I'm assuming you've tried charging it first before looking for a replacement?

Is on a trickle charge right now. The PCP runs out in August so we are hoping not to have to spend any money on it, but it's always best to check, just incase. I can't believe it's such an awkward size.

Herbie · April 27, 2020

Aha, right. I've never had a PCP (to me that's a Primary Cross-connection Point (the green street cabinets) in the BT underground telephone cables :laughing: ) but I always assumed that as you don't actually own the car then it doesn't cost you anything over and above whatever your monthly payments are. Just goes to show that every day's a school day!

Wallace · April 27, 2020

52 minutes ago, Herbie said:

Aha, right. I've never had a PCP (to me that's a Primary Cross-connection Point (the green street cabinets) in the BT underground telephone cables ) but I always assumed that as you don't actually own the car then it doesn't cost you anything over and above whatever your monthly payments are. Just goes to show that every day's a school day!

Well well what a small world, I retired from GPO/Post Office Telephones/BT/Openreach in 2012. You still have to pay for tyres etc, and batteries aren't covered out of warranty, which ours is. I'm going to leave it on charge and see what tomorrow brings.

jumbojake · April 27, 2020

my Rx dropped to 6v, but responded to a slow charge ok ... that was enough to start the car and let the DC-DC charging start.... I can see it losing charge, but just need to do that every couple of days to ensure it doesn't go to low, it would probably live like that until we're back on the road on a daily basis. For me, I need to know it will last a week without use, so replaced... plus my car is a keeper.

Herbie · April 27, 2020

14 minutes ago, Wallace said:

Well well what a small world, I retired from GPO/Post Office Telephones/BT/Openreach in 2012

Small world indeed my friend, that's amazing.

I was there 1978 to 1996 as a faultsman jointer and I loved the job. I would have been more than happy to stay on until normal retirement age (which would have been two years ago) but unfortunately I was medically retired after two discs in my back ruptured as I was digging down to find a buried joint.

One thing I can say that not many people have the chance to, is that I've been receiving my pension for longer than I actually worked in the company :thumbsup:

Inazone · April 27, 2020

My Battery started playing up at the end of last year year. I too was looking around for a replacement. Awkward size and all that. Wasn't prepared to pay 250 quid for an AGM Battery, as didn't think the extra time was worth it so I'm happy to replace this Battery every 3 or 4 years rather than 5 years... However I'm sure some people will shoot me down... But so far this Battery has been working well. Anyway link below...

https://www.ebay.co.uk/itm/372114520674

Sent from my G8142 using Tapatalk

Shada · April 27, 2020

I replaced mine with one from ecp of all places! But it has a four year warranty and was less than £90

BigChange · April 27, 2020

I'm confused. I thought a recent string decided that the "small" Battery is charged up by the hybrid Battery which, when necessary, feeds the small Battery with enough power to boot up the system and this in in turn, by starting/running the engine, puts more charge into the hybrid Battery. Or have I got it all wrong. My car is 5 1/2 years old and I'm starting to get worried with all the tales of failed start up batteries. Cars used to be so simple to understand.

Herbie · April 27, 2020

32 minutes ago, BigChange said:

I'm confused. I thought a recent string decided that the "small" battery is charged up by the hybrid battery which, when necessary, feeds the small battery with enough power to boot up the system and this in in turn, by starting/running the engine, puts more charge into the hybrid battery. Or have I got it all wrong. My car is 5 1/2 years old and I'm starting to get worried with all the tales of failed start up batteries. Cars used to be so simple to understand.

Because hybrids don't have a normal starter motor Toyota/Lexus decided they could save a bit of money by using small capacity 12V batteries - my RX has a 51Ah Battery whereas previous cars have been a minimum of 75Ah capacity. A traditional starter motor will take 300A or more to crank the engine but a hybrid doesn't do that. The 12V Battery only has to boot the computers and one or two other things to get the car READY and draws well under 20A to do it, hence why they decided on smaller-capacity batteries, the downside of which is that they can't be left standing as long as others before they go flat.

In a conventional car the Battery is only used to crank the engine. Once the engine fires and the alternator is spinning, it's the alternator that feeds all the car's electrical demands and if there's enough spare capacity it will also keep the Battery charged up.

Hybrids don't have an alternator but make use of a DC/DC converter instead. This takes the 288V of the traction Battery and converts it to approximately 14.5V to do the same job as the alternator would, ie, to keep the 12V Battery charged. It also provides 48V (if I remember correctly) to power the motor for the electronic power steering as well but that's not really relevant here.

The traction Battery is charged by either regenerative braking or by the petrol engine running when it needs to.

Shada · April 28, 2020

8 hours ago, BigChange said:

I'm confused. I thought a recent string decided that the "small" battery is charged up by the hybrid battery which, when necessary, feeds the small battery with enough power to boot up the system and this in in turn, by starting/running the engine, puts more charge into the hybrid battery. Or have I got it all wrong. My car is 5 1/2 years old and I'm starting to get worried with all the tales of failed start up batteries. Cars used to be so simple to understand.

Shada · April 28, 2020

Simplest way to put it is they use the small Battery to power the electrics that switch on the big Battery.

Small Battery flat means no go

Barry14UK · April 28, 2020

Although the Traction Battery supplies charge to the 12v Battery once car is operational, the process requires that there is sufficient charge in the 12v Battery to initiate this which means as a prerequisite the 12v Battery is good enough to sufficiently hold a level of charge. Even a new 12v Battery will not do this for months without use or by being charged from another source and as the Battery ages it will require the car to be used more often or charged another way to A insure car can be used when required without adopting an emergency start and B to help prolong the life of the 12v Battery which will last longer if not allowed to go flat.

Bootleg · April 28, 2020

I first had a the flat Battery back in January, after had my 2 year old IS300H for 6 months. Called out the AA and then had it checked out at local dealer who said it didn't need replacing. In the current climate of course, it is now flat again having last been used 3 weeks ago (although the sense of passing time is a bit weird at the moment). I saw the email from Lexus to start it up periodically. I haven't done this. Any views on how long you should do this for?

It looks like I need a trickle charger. The CTEK MXS 500 appears to be the recommended charger. How long will I need to run it, to get to a point where the car will start? Why a trickle charge? Are there other alternatives to get it up and running more quickly?

I have off road but not secure parking, will I just run a power cable out to the car perhaps going in an open window? Will there be alarm issues?

Thackeray · April 28, 2020

50 minutes ago, Bootleg said:

Are there other alternatives to get it up and running more quickly?

You could start the car with one of these mini jump start devices like this

The prices seem to have gone up recently - perhaps lots of people are buying them because of flat batteries. Previously they were available for £20-30. I don't know this particular brand but there are a several of this kind of device available.

Once you've started the car, it will charge normally. Or if you don't run it for very long you can trickle charge the Battery later with a separate charger.

Bootleg · April 28, 2020

41 minutes ago, Thackeray said:

You could start the car with one of these mini jump start devices like this

The prices seem to have gone up recently - perhaps lots of people are buying them because of flat batteries. Previously they were available for £20-30. I don't know this particular brand but there are a several of this kind of device available.

Once you've started the car, it will charge normally. Or if you don't run it for very long you can trickle charge the battery later with a separate charger.

Thanks - I had one of devices for a previous car, and it burst during use, so I'm rather nervous of them. I see there's another thread covering this. In all my research before purchasing the IS300h, I never came across this issue. Trouble free motoring seemed to be guaranteed.

Herbie · April 28, 2020

2 hours ago, Bootleg said:

I saw the email from Lexus to start it up periodically. I haven't done this.

Um....why not?

2 hours ago, Bootleg said:

Any views on how long you should do this for?

As long as the lockdown continues or until you can regularly use the car again.

The advice on Toyota's website is to put the car into READY mode for 60 minutes each week, making sure that anything like radio, aircon etc., etc., are turned off so that most of the available energy goes into keeping the Battery charged.

2 hours ago, Bootleg said:

It looks like I need a trickle charger. The CTEK MXS 500 appears to be the recommended charger. How long will I need to run it, to get to a point where the car will start?

That's not what a trickle charger is for.

All batteries will discharge with use or 'self-discharge' when not being used. A trickle charger is a full-blown Battery charger that will charge the Battery up to full, but if left connected will then keep a 'low-grade' or 'trickle' charge going in to the Battery to avoid self-discharge.

2 hours ago, Bootleg said:

Are there other alternatives to get it up and running more quickly?

Yes. As William says above, one of those small jump start Battery packs will get it going quickly.

Quote

In all my research before purchasing the IS300h, I never came across this issue. Trouble free motoring seemed to be guaranteed.

It still is, to the degree that anything can be guaranteed. This isn't a fault or a breakdown, rather just a bit of bad design. My RX450h has a Battery with a capacity of 51Ah but as I said earlier, all batteries will self-discharge over time if not used, plus, of course, there's always a small quiescent current drain on the Battery anyway, to keep the alarm energised, to keep the radio presets in memory etc., etc., so even a Battery of 110Ah would eventually go flat if the car isn't used or some form of trickle charger is not connected.

Wallace · April 28, 2020

Thanks for all the input. I've had the Battery on charge, on and off since yesterday, as I was celebrating rather late yesterday and it's raining today, so anyway it starts OK and I will try and take it for a run, not too far from home, and see how it goes. Just one question, if these small jump start Battery pack will do the trick, can't you just put any 12volt Battery across the flat battery terminals to get it going?

Herbie · April 28, 2020

28 minutes ago, Wallace said:

Just one question, if these small jump start battery pack will do the trick, can't you just put any 12volt battery across the flat battery terminals to get it going?

As far as I can tell (my meters have a range high enough to read peak current but won't latch or hold onto it) there's a momentary inrush current of 15-20A, but literally just for a fraction of a second, so if a 12V source can deliver that then yes, almost any 12V Battery will get the car into the READY state.

This is why I can never understand why people have so much trouble understanding the principle of jump starting.

12 Volts is 12 Volts is 12 Volts and all you're doing is supplementing a dodgy 12V source by piggybacking a good 12V source on to it - it's not witchcraft or black magic :laughing:

A little tip - if the Battery is knackered and needs to be changed, you can even just use a pack of 8 AA batteries (in a holder like the one below) connected to the cables to keep the various settings alive while the Battery is disconnected. NB - this wouldn't provide enough power to get the car started, just in case anyone was thinking about it :laughing:

jumbojake · April 28, 2020

if your using that type of source, need to make sure it is about 14.5v.. or better, connect with a diode ... otherwise connecting a brand new car Battery might cause a large current spike into your AA batteries (acid/fire risk). Don't underestimate the power in a car Battery, a slight potential difference could unleash a large current spike.

Bootleg · April 28, 2020

1 hour ago, Herbie said:

3 hours ago, Bootleg said:

I saw the email from Lexus to start it up periodically. I haven't done this.

Um....why not?

To be honest, with one day being very much like the other I am completely unaware of the passage of time or what day of the week it is 😉

1 hour ago, Herbie said:

3 hours ago, Bootleg said:

Are there other alternatives to get it up and running more quickly?

Yes. As William says above, one of those small jump start Battery packs will get it going quickly.

Thanks - despite being a scaredy cat I'll go down this route.

Thackeray · April 28, 2020

3 hours ago, Bootleg said:

I had one of devices for a previous car, and it burst during use, so I'm rather nervous of them

1 hour ago, Bootleg said:

despite being a scaredy cat I'll go down this route

What happened? Were you starting a conventional car with a conventional starter motor? Did the device claim to be big enough to start whatever size of engine you were starting?

Of course, in a hybrid car, you're only booting up the computers so the current really shouldn't be enough to overload the jump starter, particularly if it claims to be big enough to start, say, a 2.5 or 4 litre engine.

Thackeray · April 28, 2020

I've been puzzled by the advice from Lexus that it's a good idea to put the car in the Ready state for an hour, once a week, but with the climate control (and the radio) turned off. I couldn't see what difference it would make whether these were on or not, as long as the 12v circuit was showing around 14.5v all the time.(Except of course, fuel would be used to keep you warm or cold or entertain you through the radio.)

So I decided to put this to the test and try to find out why they give the advice. I've come to the conclusion that it won't make any difference to the charging of the 12v Battery but it might use a bit of fuel keeping you warm or cool. But then maybe you're happy to use the fuel if it keeps you comfortable and makes no difference to the 12v charging. This is what I found.

1. Power generation didn't start for two or three minutes while the engine is going through its initial warm up phases.(You can feel the generator load come in and see the generation start on the energy graphic.)

2. When power generation does start, it took around 4-5 minutes to increase the hybrid Battery charge from two to six bars.

3. If the cabin heat is on, the engine cycles through a pattern of one minute running followed by two-three minutes off.

4. Over the course of the next 40 minutes or so, only six out of nine one minute runs of the engine involved power generation; presumably the engine is running at other times solely for cabin heat.

5. For the last 10 minutes of the hour, the cabin heat was turned off and the engine did not run at all, even though the hybrid Battery charge fell from five to four bars.

6. In the course of the hour, the hybrid Battery started at two bars, rose rapidly to six bars and then slowly declined to four bars. The 12v circuit started at 11.5v and ended at 12.3v.

So I estimated that if I hadn't had the climate control on (outside temperature was 9C) the engine would only have run for an initial four-five minutes, plus around six one-minute bursts during the hour. That's to say, the engine would have run for about 10 out of 60 minutes. It ran more than this when I had the climate control on but I can't see how this could have affected the charge rate as the 12v circuit showed a constant 14.2v. Last week when the outside temperature was 20C it showed a constant 14.4v.

I also listened to the radio but I don't think that could have affected the charge rate.