12V battery, some random thoughts

[Dancing Badger]

Some ruminations while we're all locked down. I suppose it comes to us all. After 3 years with my Gen 3, 4 years with my Auris Hybrid and now 2 years with my current Gen 4 I have for the first time had to fix something on my car. Last night She Who Must Be Obeyed suggested I nip out for a chippy tea. That's not a suggestion I'm in the habit of arguing with so I jumped into the Prius to drive to the chippy (it's too far to walk, the chips would get cold). I haven't used the car for about 3 weeks since the latest lockdown as I'm working from home, so when the door mirrors seemed a bit sluggish as I unlocked the car my heart sank. And sure enough it wouldn't start and scolded me that the 12V Battery was low. I had a couple of tries, but when it started strobing the house over the road with its headlamps I figured I ought to do something about it.

So I disconnected my Ctek trickle charger / Battery maintainer (I have a faster charger but I thought this was safer) from my 1961 Hillman Minx in the garage and hooked it up to the Prius. And that got me thinking. The Minx is my big boy's toy, does less than 1000 miles a year so the Battery needs looking after - giving it a run does put a charge in but with a dynamo putting out around 22A maximum and a not terribly sophisticated two bobbin regulator it's just not enough - with use of the Ctek I usually get 6 or 7 years out of the battery. But the battery is either too flat to start the car (and it has a starting handle so if I'm feeling energetic I can get it going even when it's fairly flat) - or it's not. If it's got sufficient charge the car just starts. But the Prius.......

I left it charging for a while, and when the charger reported it should be ready to start I gave it a go. And it started. Woo hoo. But then it started shouting at me that there was a problem with the hybrid system, there was a problem with the intelligent parking wotsit, there was a problem with the collision avoidance doofer, consult your dealer, do not pass go, do not collect £200. I'm not sure that I approve of being told off by my car. I have never come to terms with how judgemental the Gen 4 is when I turn it off, remarking that I shouldn't use my heater and such.

Anyhow, I knew that I'd read about this kind of thing on here, so I came to have another look. I'm a regular lurker here but don't post much - I don't generally ask many questions because I find that if I scroll down a few pages I usually find that the question has already been answered (and because the cars are so boringly reliable that I don't have many questions) - and sure enough I found the answer.  I'm not alone, other people have had that, and it's not a big deal. Keep restarting it and the scary messages will go away after a bit. So I did, and they went away, and now the car seems fine. Job's a good 'un, lesson learned, I'll be a bit more disciplined about making sure I run the car for half an hour or so at least once or twice a fortnight, or better take it for a drive, and I've also ordered one of those jump start thingies that somebody recommended a few pages back. Maybe invest in another trickle charger.  Oh, and we didn't miss out on our chippy tea, I went and fetched it in SWMBO's little van.

But my thoughts turned back to my Minx - I love driving it but it'll be 60 years old next March and I've had it for 35 of those years (I'm the second owner) so I know its limitations. It's very heavy to drive - no power steering, no power brakes, no power anything. It's slow, doesn't handle or stop well, is not very comfortable and lacks all the creature comforts we have come to take for granted. I wouldn't want to use it every day, and although I regularly used to I no longer feel comfortable taking it long distances - whereas I'm happy to drive my Prius for 2500 miles around Europe for a fortnight's holiday, happy to regularly drive 600 miles in a day to watch my football team away from home. But I know how the Minx works, I understand it. If I had to I could take the engine out, strip it to its component parts, knowing what each of them is, what it does and how it does it; and put it back together again, using just a few basic tools. If it's running poorly or won't start I can diagnose the problem using nothing more sophisticated than a 12V test lamp and my eyes and ears. And nobody wants to steal my exhaust. 

But the Prius? Oh, I've watched the YouTubes about how the HSD operates, I get the principle but I only open the bonnet to check the levels and that's it - other than that I leave the dealer to deal with it. And the thing is that none of my hybrids have needed me to do anything more than that until now. I used to carry a full set of tools so I could do roadside repairs. Now I don't even have a spare wheel (I would like one but am too indolent to do anything about it). We've gained a lot more than we've lost - I love my Prius, there's a reason I'm on my third Toyota hybrid - but I do sometimes feel a bit helpless with it. If it was less reliable maybe I'd have to make the effort to learn, but I'm not complaining about that. Still, it's a price worth paying - and if I feel a bit nostalgic for getting oil on my hands and grease in my hair I have what I need in the garage. Well, this is a story which didn't go anywhere much or shed any light on anything, but it has passed a few minutes in the telling, perhaps it may amuse. 

TL;DR, the 12V battery on the Prius can be an issue if you don't use the car. When you start it after charging it can throw up a load of error messages, but they go away after you restart it a few times. And old cars were much simpler, but nowhere near as good.

[TonyHSD]

Very nice story to read, thanks for sharing with us. 👍🚗

[flash22]

The hybrid cars use an AGM Battery they need to charge low and slow - ctek is ideal but can take 24-48 hours to charge, modern electronics hate low voltage if they cant talk they will throw a hissy fit

[Ten Ninety]

Nice read, well written. Thanks for posting.👍

8 hours ago, Dancing Badger said:

And nobody wants to steal my exhaust.

[kithmo]

On 11/20/2020 at 12:15 PM, flash22 said:

The hybrid cars use an AGM Battery they need to charge low and slow - ctek is ideal but can take 24-48 hours to charge, modern electronics hate low voltage if they cant talk they will throw a hissy fit

My Gen 4 (original OEM) battery isn't an AGM Battery, it's just a normal Lead acid wet cell with caps for topping up the cells.

I use my 3.8A Ctek for topping up the Battery about every 6 weeks and it takes around 6 hours just to top it up so 24 hours or more sounds about right from flat. 👍

[flash22]

51 minutes ago, kithmo said:

My Gen 4 (original OEM) battery isn't an AGM battery, it's just a normal Lead acid wet cell with caps for topping up the cells.

I use my 3.8A Ctek for topping up the battery about every 6 weeks and it takes around 6 hours just to top it up so 24 hours or more sounds about right from flat. 👍

they must have changed it when they went to the 1.8 or is it a plug in ?

[Notoyboy]

Not so many will even recognise a Hillman Minx, without googling 🤤

As you say, the great benefit of the older "classic" cars is their simplicity, compared to modern laptops on wheels, although we forget the need to regularly do the points and tappets!

[PeteB]

1 hour ago, flash22 said:

they must have changed it when they went to the 1.8 or is it a plug in ?

The Gen 4 Prius had the 12V Battery in the engine bay, no the boot, so there was no need for an AGM Battery.

[johalareewi]

Just to confirm what the other posters said. The gen4 prius and gen2 plugin prius have a lead acid Battery under the bonnet not an agm Battery.

[matteos]

I also happened to discharge the Prius' small 12volt Battery after a period of non-use for the lockdown. I've devised a protocol to get around this. If you plan not to use the Prius for long periods of time it is best to drive a few miles in Sport mode before storing the Prius in the garage. In Sport mode the main Battery is fully charged and then will continue to keep the small 12V in shape during the long lockdown period.

[TonyHSD]

The only thing to do any car owner, especially the hybrids owners is to put the car into ready mode once a week for around 30min to an hour and no need to drive the car at all this will help maintain 12 v Battery. The owners who were driving their hybrids exclusively in town and short journeys prior to lockdown should keep their cars in ready mode for longer as their 12 v batteries are in worse state than the ones that had been used more often and on longer trips. Batteries likes to be charged and discharged regularly., no matter what types they are or on what car, vehicle or device been used. 

[Chris Dance]

At three years our Gen 4 Battery went dead. AA chap said it had died mainly because I had only used it for short Journeys. It was the first lock down and Toyota dealer was closed so I paid for a Bosch Battery directly from the AA man. The AA chap recommended taking the car on a motorway run about once a week; this is what I do.

I used to service the cars I owned in the 60s 70s and 80s. My first car was a Renault Dauphine and was easy to maintain. I had several Simca cars, I did lots of miles and service was every 3,000 miles. I still have my grease gun and spanner sets. The Volvo I owned was a bit more involved with regard to servicing. I would never consider working on the Prius; I am an oldie so I do not feel like lying under cars these days.

 Hybrid Prius cars I consider to be the most reliable cars and easy to drive I have ever owned.

 

[johalareewi]

Why would driving your hybrid around to top up the12v Battery be better than leaving the car in ready and not driving it anywhere?

Toyota hybrids charge the 12V Battery from the HV Battery when in ready mode. Driving around is just going to waste petrol.

[kithmo]

3 hours ago, johalareewi said:

Why would driving your hybrid around to top up the12v battery be better than leaving the car in ready and not driving it anywhere?

Toyota hybrids charge the 12V battery from the HV battery when in ready mode. Driving around is just going to waste petrol.

I do it mainly to clear surface rust off the brakes so it doesn't build up because mine is parked on the drive out in the weather.

[TonyHSD]

It’s better option to drive the car for that reasons but for the Battery only no need to, ready mode 30-60mins weekly is just fine. 

[Dancing Badger]

I appreciate that from the point of view of keeping the Battery charged it doesn't matter whether the car is driven or just parked up in ready mode, but I prefer to take it for a drive because sitting in it in the driveway for 30 - 60 minutes is boring - it's counterproductive to vacuum the car because the vacuum is an electrical drain and there's only so much dusting you can do, and I've been through all the menus and settings and exhausted the novelty value there. 

I also find it somewhat disconcerting if I just sit in the car while it's in ready mode reading a book or something and then the engine suddenly fires up - it always takes me by surprise. So as I won't leave the car unattended in ready mode, I'd rather take it for a drive out, preferably somewhere scenic.

And I enjoy driving it, and am not getting much opportunity to do so at the moment. 

[Chris Dance]

I consider driving the better option to keep the Battery charged. Driving ensures all the systems are functioning as well as the corrosion of the brakes. The Prius is also a joy to drive.

[Sooty]

Driving around is better for the tyres as well. Keeping them in the same spot for too long can cause flat spots and also weaken the side walls.