Another battery problem

[Will004]

Hi

I foolishly let the auxillary Battery on my Gen 4 go flat and it's barely holding 12v, and only for less than a week. Anyway, my problem is a couple of malfunctions which have appeared since. First the HUD seems unusable. On the adustment screen it won't move up so I can see it (and maybe it's also not actually on). The yellow bar stays at the bottom. Secondly, the clock was out by the best part of an hour but when I finally tried to adjust it the clock settings have disappeared, along with most other settings on the MFD. Have I corrupted the computer? The first time it went flat I let the AA start it but then bought my own jump pack which I've used once. No problem starting it.

Anyone experienced anything similar? The car drives fine and everything else (so far) seems OK. Is there anyway to reset the computer?

Thanks

Steve

[flash22]

Disconnect the Battery for 15 mins or so, then reconnect it, low voltage does strange things on modern cars

[BhxTrev]

Bob that’s very interesting & Steve please let me know if that works. I’m not using my Gen4 Prius much at the moment & getting a flat Battery has concerned me. I’d like to know just in case I have the same problem during this lockdown. 

[FROSTYBALLS]

Also see -

 

[Will004]

Thanks Bob.

I suppose my problem is whether to just to leave it on the basis that the car works and there's no warning lights flashing. After all, a clock and HUD are not essential equipment. On the other hand, I have only driven locally in the lockdown so can't say that things like lane departure and dynamic cruise control are OK.

Is there a risk disconecting the Battery without access to a Toyota centre to sort it out if it all goes wrong? I'm making sure the Battery is keeping enough charge by using it at least twice a week but I'm pretty sure a new one is a must when this is all over. What would others do?

Steve

[BhxTrev]

Steve, I’m no expert but back in my student days In 1960s, I worked part time serving petrol & also fitting car tyres & batteries in a service station. Quite a few people bought batteries only to come back because the Battery wasn’t the problem. Among many things the dynamo, as it was called then, was frequently at fault. If your thinking about buying a new Battery I therefore suggest you get your Toyota dealer to test the electrics & the Battery before you fork out money for a new battery.

[Chris Dance]

It would appear that several Gen 4 owners are having Battery problems after 3 years + a month or so. I think it is a good idea to let your dealer diagnose the issue,  The Battery on our car went completely flat. The AA chap said the Battery was shot. He said doing short runs kills a battery.. AA fitted a new Bosch battery. I now take the car on a decent run using a by pass to really charge up the battery once a week. 

[Catlover]

My Gen4 is 3 year 8 months old and I have no 12v Battery problems as of yesterday (not been out today). Just saying.

[BhxTrev]

Hi Joe, my Gen4 is about the same age as yours. It’ll be 4 years old on 1st September, & I’ve had no Battery problem whatsoever so far. My previous car, a Gen3 Prius, was well over 6 years old when I changed it for my present car & I never had any problems with its Battery. In fact other than services, MOTs & a few tyres, that car did sixty odd thousand miles & that’s all I ever had to pay out for. I didn’t even need to change the brakes pads. It’s little wonder I bought another Prius.

[QuantumFireball]

11 hours ago, Will004 said:

Is there a risk disconecting the battery without access to a Toyota centre to sort it out if it all goes wrong?

I think the risk is low, just disconnecting the negative terminal for a few minutes isn't an unusual thing to do when a modern car is misbehaving like this.

11 hours ago, Will004 said:

I'm making sure the battery is keeping enough charge by using it at least twice a week but I'm pretty sure a new one is a must when this is all over. What would others do?

I got a smart charger plugged in all the time to maintain the 12V Battery. Lead acid batteries don't like not being used, short trips aren't good enough for charging it, and I don't want to be doing unnecessary driving just to charge the Battery. Leaving lead acid batteries discharge beyond a useful voltage causes sulfation which can mean permanent damage.

[kithmo]

1 hour ago, Catlover said:

My Gen4 is 3 year 8 months old and I have no 12v battery problems as of yesterday (not been out today). Just saying.

Tempting fate there Joe 😟

 

[kithmo]

No problems with my 12v after 4 years 2 months of nearly all short journeys. But I do put my Ctek conditioner on it every 6 weeks or so.

I have a Battery meter permanently connected via the 12v power socket and interestingly, usually when the Battery is getting low, in ready mode the car charges at just over 14v whereas just after I've conditioned it it charges at just over 12v. The 14v reading gives me an indication it's time to put the charger on. 

[Will004]

I bought a meter (as well as the jump start pack). On ignition auxillary it reads 12v or so (this is after a run). Put it in Ready and it jumps to 14v, so Kithmo's experience suggests it's still not charging properly, even after a 15 mile drive.

I first noticed the Battery was low after that stormy weather we had in the winter and I didn't use the car for a couple of weeks. I had a low 12v Battery warning but it still started. It's been downhill ever since. But I had a Gen 2 from new years ago when we always went away during the winter for 3 or 4 weeks - no problem then even though the Battery was tiny compared with the current model. So I tend to agree with Chris that some batteries at least are just not up to scratch.

[QuantumFireball]

7 minutes ago, Will004 said:

I bought a meter (as well as the jump start pack). On ignition auxillary it reads 12v or so (this is after a run). Put it in Ready and it jumps to 14v, so Kithmo's experience suggests it's still not charging properly, even after a 15 mile drive.

Around 14V when in "Ready" mode is absolutely fine, it means it is charging the Battery which is often expected while running the car, especially just after starting it.

You should be checking the voltage when the car is completely off (no load). Over 12.6V or so is ideal, though anything over about 12.0V should be OK for starting. Below 12.0V means a higher risk of problems starting, and risk of damaging the Battery from discharging too much. Hard to find accurate SOC figures for AGM batteries as many claim the charts often shared online are wrong for AGM.

I usually find mine around 12.1 to 12.3V after being left unused for a few days. The battery's 8 years old so probably not in the best shape. I'll buy a new one when I'm driving regularly again.

[Will004]

Back to my original question (the apparent computer problems) and thanks for the suggestions. I'm still unsure how to proceed with no access to Toyota anywhere unless you're a key worker. I agree it is probably low risk disconnecting the Battery for a bit to 'reboot' the car. But what if it does go wrong and more faults show up which makes the car undrivable? Would Toyota Assist (eg the AA) sort it out or would I have to wait for an indefinite period for Toyota to reopen?

And then there's the warranty issue. Would the cost be covered after I had done some DIY? Same with a third party Battery - any warranty issues? My feeling now, given the unusual situation we are all in, is to be leave it alone and make sure the Battery doesn't completely discharge. I can live without a clock and HUD.

[BhxTrev]

Steve, when I have problems with my iPads, PC, iPhone, that seem unresolvable, my first action is to reboot the system. In the case of my PC it’s been so locked up i can’t just reboot it, I’ve literally just simply switched it of at the plug left it a short time, then switched it on. I guess that’s not to be recommended if you can do a normal reboot but I’ve never had a problem whenever I’ve done that & it usually resolves the problem. Taking the negative terminal off your Battery is the same as just unplugging a computer. It might just solve the problem because it does sound as though your cars computer has become corrupt. This action should make the computer restore its original programme information so everything goes back to what it should be. Let’s face it when the Battery needs changing & the old one has been disconnected surely it’s no more than what you’re doing? Maybe it might be worth contacting Toyota customer services for advice, that’s if they are available, just to check if taking this terminal off would be a problem if you’re still not sure.

[Will004]

Not sure about your analogy Trev. Most people have multiple devices so even if you did completely wreck a phone or PC etc there's usually an alternative to fall back on. We have only one car and no way am I using public transport in London at the moment. It's all a question of risk - probability and impact. I agree the probability of something going wrong is low but the impact is significant, that's the difference. The fallback here (getting Toyota to sort it out) is not available. Thanks for taking the time to try and convince me, I appreciate it, but I think the discussion so far has convinced me to take a conservative approach until normality returns (if it ever does!)

As far as I can see Toyota customer services aren't operating, unless anyone knows different.

[BhxTrev]

Steve, I certainly appreciate your dilemma. I think I would want some reassurance before disconnecting the Battery that things would not be made worse. Some dealers are starting up again, from what I can make out so would it be worth you phoning round? I used to use Motorline in the Midlands for services & found them to be very good. They have emailed me recently to say they’ve opened their service centres since 11th May. It may be worth giving them a call on 01384 505404, I’m sure they’ll be happy to give you some advice. 

[Will004]

Thanks. I've just had a look at London centres and it looks like my usual one does have people to answer 'simple' queries on service and sales. I'll give tem a try first.

[kithmo]

6 hours ago, Will004 said:

I bought a meter (as well as the jump start pack). On ignition auxillary it reads 12v or so (this is after a run). Put it in Ready and it jumps to 14v, so Kithmo's experience suggests it's still not charging properly, even after a 15 mile drive.

I first noticed the battery was low after that stormy weather we had in the winter and I didn't use the car for a couple of weeks. I had a low 12v battery warning but it still started. It's been downhill ever since. But I had a Gen 2 from new years ago when we always went away during the winter for 3 or 4 weeks - no problem then even though the battery was tiny compared with the current model. So I tend to agree with Chris that some batteries at least are just not up to scratch.

It may jump to 14v on initial start up. if it stays at 14v and doesn't settle down to 12v after a run then I would say it indicates the charging system is working overtime to keep a failing Battery charged up.

[BhxTrev]

Hi Keith, after reading your earlier post I’ve just sent for a Battery meter. I didn’t know they existed but as my car is getting older I thought it pertinent to put one in especially as it fits so neatly in the 12V socket. At least now I can keep a close eye on my Battery health & get it sorted if it starts to deteriorate. Cheers.

[HughL]

I had a Battery fail early on in lockdown; emailed customer services who were very helpful and ended up arranging for the AA to fit a new one free of  charge. I was very clear that I wasn't a key worker and not an urgent case in any way, but they seemed happy to do it regardless.  Toyota roadside assistance membership helped.

[Will004]

Thanks for that info Hugh. I have emailed customer services. I'm also a TRA member.

[John Walton]

After my gen4 had not been used for a few weeks I checked the Battery with a volt meter and found it was low. I phoned my local Toyota dealer for advice. The person who answered told me the dealership was closed and he was working from home .He could not give me an answer but arranged for someone to call me. Within as hour I had a phone call, I explained the problem and he advised me that it would be OK to connect a charger direct to the Battery without disconnecting it from the car, this I did and all seems ok. Now every couple of weeks I connect the charger and charge it for a hour or two so as to keep the Battery fully charged. The charger I am using is a small CTec.

[Joseph D]

11 hours ago, John Walton said:

Now every couple of weeks I connect the charger and charge it for a hour or two so as to keep the battery fully charged.

Unless the Battery has been fully charged at some stage, an hour or two every two weeks is not enough.

If the Battery is more full than empty, then one to two hours may be ok, but you should leave the charger on until at least the indicator shows the Battery is fully charged.

As you say you have a CTEK, the best idea is to just leave it on anytime you are not driving it. The charger will automatically change to maintenance mode once the battery is fully charged.