Rav4 Hybrid Not Starting.

[Kwacker]

Thanks roadster-rav, on balance with little knowledge of electricky I think I’ll stick to the jump start option. Someone mentioned to me that it might be possible to get the current level of charge of the drive and ancillary batteries from a setting on the infotainment screen - do you know if this is possible?

[roadster-rav]

15 hours ago, Kwacker said:

Thanks roadster-rav, on balance with little knowledge of electricky I think I’ll stick to the jump start option. Someone mentioned to me that it might be possible to get the current level of charge of the drive and ancillary batteries from a setting on the infotainment screen - do you know if this is possible?

I haven't come across anything that shows the 12 volt Battery voltage but the traction Battery displays use that bar gauge both on the centre display and the infotainment one. Using the HybridAssistant app on a tablet or phone along with the recommended bluetooth diagnostic device gives much more information and it briefly reports the 12v Battery voltage before the car is switched on. Once the car is in ready mode there isn't much point in measuring the 12v battery because it immediately jumps up to the charging voltage. What might work ( I haven't tried it) would be to use one of those cigar lighter voltmeters and look at the reading with the car in neutral where my understanding is that traction power is switched off.

[Gerg]

2 hours ago, roadster-rav said:

the car in neutral where my understanding is that traction power is switched off.

I'm not a RAV owner, but I think when in neutral and the parking brake is not applied, then the engine will not run to replenish the traction battery if it gets low.  But the traction battery/inverter will still be maintaining the charge of the 12v Battery in spite of this, just without the support of the thermal engine.

You'll be able to see the actual charge of the 12v Battery when the car is in the 'acc' mode if you were looking at it via a cigarette lighter voltmeter.

That's my understanding from when I use my cigarette socket voltmeter on our Auris, anyway.

Hopefully this doesn't come across as overly pedantic!

[roadster-rav]

21 hours ago, Gerg said:

I'm not a RAV owner, but I think when in neutral and the parking brake is not applied, then the engine will not run to replenish the traction battery if it gets low.  But the traction battery/inverter will still be maintaining the charge of the 12v battery in spite of this, just without the support of the thermal engine.

You'll be able to see the actual charge of the 12v battery when the car is in the 'acc' mode if you were looking at it via a cigarette lighter voltmeter.

That's my understanding from when I use my cigarette socket voltmeter on our Auris, anyway.

Hopefully this doesn't come across as overly pedantic!

That's done it! I'll have to grab my voltmeter and go out and check this now. Will report back!

[roadster-rav]

6 hours ago, roadster-rav said:

That's done it! I'll have to grab my voltmeter and go out and check this now. Will report back!

You are right Gerg. I actually misread or misremembered what the manual says about neutral. It is actually the traction Battery which does not charge in neutral even in READY mode with the engine running. To check the 12v Battery status from the 12v sockets inside the car you need to be in accessory mode or ignition on mode, i.e. press the button without foot on the brake. For example my readings are as follows :-

everything off : 0 volts i.e. cigar lighter sockets not live.

ready mode: 13.4 volts ( gear selector in any position) i.e. charging from the traction Battery.

accessory mode: 12.2 volts i.e. not charging and 12v battery a bit depleted.

[Kwacker]

Long conversation with my son ( who is an electrical/electronic engineer) this afternoon. Apparently the jump start option with a Ring type pack will only work if the ancillary Battery has 12 volts or more remaining. So I’ve invested in a voltmeter as discussed to monitor the ancillary Battery to see if the drain ever gets below that limit. We’ll see if there is actually a problem!

[Derek Jones]

we have a 66 rav 4 hybrid which we purchased 13 months ago. Its our first hybrid which we thought would prepare us for the changes taking place with the move for green energy.  At first we were very pleased with the car but then went into the second lockdown. The car was left for about three days before we needed to use it to get to an hospital appointment, it refused to start. there was a lot of electrical noise from the front and some flickering of the instument panel. After a few attempts the car suddenly started. Our local dealer told me it needed a trickle charger to keep the Battery topped up. Having just read the post that a rav 4 hybrid was left for 17 days and started I now know that the dealer was feeding me a line of BS. Any advice would be well received, I have two months left on the warranty and need the problem sorted.

[Heidfirst]

Hi Derek, welcome to TOC,

All Toyota hybrids use a smaller 12V Battery than conventional ICE cars because they do less (e.g don't have to turn a starter). If you have something with parasitic drain e.g. a Dashcam then it's easier to drain the 12V especially if you haven't been doing enough mileage to keep it topped up (I even suffered from that this year with a conventional ICE car thanks to lockdown). Occasionally a Battery itself may be weak especially after a few years so it is certainly worth following up with your dealer (or another if you have 2 or more in your vicinity).

 

p.s. I don't think that you needed to underline all of your post.

[FROSTYBALLS]

Underlining removed.

Toyota's advice on Battery maintenance published April 2020:

 

[ColinB]

After my C-HR suffered from a flat Battery for the second time I've bought a solar charger to keep the Battery topped up if I'm not going to use it for a few days. At least the booster pack that I bought started it in seconds. 

[Peterd23]

From my early Prius ownership days I have always been of the opinion that the 12 volt Battery only has a life expectancy of about 5 years. The only time I had a problem was at about that time. It is possible you might benefit from investing in Battery replacement, 3 days is a very short time to lose charge. I left my 66 plate for much longer than that without a problem.

P.S. For dealer BS beat this: asked one dealer to check out the 12 volt Battery on my 5 year old Prius - the response was that I should know as I would have problems starting - "you start it just like any other car" !!