R4P... Seriously let me down

[ernieb]

I’ve not had the issue so far and the lowest voltage I’ve seen in ACC mode is 11.5v It’s still relatively mild so it will be interesting to see what happens as it gets cooler. I also have not used cabin preconditioning for some months. Following Philips line of thought of the people who have reported problems a number have been associated with leaving the boot door open. There is the initial power drain with the door opening and obviously the boot internal light but this in itself does not seem to be enough of a power drain to flatten a Battery unless something else gets activated with the boot open?

[Nick72]

4 hours ago, philip42h said:

OK, so drifting back towards the original topic ... 😉

We know that if you leave any car standing idle long enough it's battery will go flat. Toyota hybrids have relatively modestly sized auxiliary batteries and modern cars have higher 'idle drain' currents than earlier cars so that the auxiliary battery will run flat in a relatively short time. Toyota suggest 60 minutes a week of Ready / run time to overcome the 'idle drain'.

We've had one or two owners do silly things (in hindsight) like leaving the car in Accessory mode, and one or two relatively inexplicable auxiliary battery issues, but most of us just drive the car with no issues at all. The wife has  a C-HR, isn't aware of the problem and doesn't need to be. We are both retired, have no regular commute and drive infrequently, irregularly or both. Looking back through the MyT data I managed to drive for a total of two hours in June (so less that 30 minutes per week) and the car was just fine - maybe I was just lucky ... 🙂

There does appear to be some anecdotal evidence that the issue is more prevalent on the PHEV than the HEV - which is perhaps 'odd' since the PHEV has the higher capacity battery ... so, why?

I suspect that the remote aicon / preconditioning feature (available on the PHEV but not on the HEV) may have something to do with this. We know that the PHEV is equipped with a heat pump for more efficient heating and cooling when the ICE isn't running. We know that the heat pump is powered from the traction battery - I don't know but my guess would be that it is a standard 230v / 110v AC compressor that is used to drive the heat pump. But I would guess that everything else - heated windows, mirrors, fans etc. - are powered from the 12v auxiliary battery in the normal way, and that would drain a relatively modestly sized auxiliary battery quite quickly.

So, my question would be do we know whether or not the auxiliary battery is charged from the traction battery while remote aircon / preconditioning is active irrespective of whether the PHEV is plugged in for charging or in Ready mode? I begin to suspect not ...

Had no issues either until the incident including hardly using the car for weeks at a time. Never an issue at all. But remote starting the air con may be the key matter. Though traction Battery was virtually full.

[Nick72]

Wonder if anyone would be willing to try the following...

 

1. Set air con to off in the car. Yes, to off. 

2. Get out and lock the car.

3. Press the remote air con on the fob.

4. Leave it 5 or 10 min.

5. Unlock, get in the car, and see if it starts.

 

May need to have your NOCO LOCO ready. Just wondering if there's something weird happening here. 

 

 

[nlee]

12 hours ago, Nick72 said:

Wonder if anyone would be willing to try the following...

 

1. Set air con to off in the car. Yes, to off. 

2. Get out and lock the car.

3. Press the remote air con on the fob.

4. Leave it 5 or 10 min.

5. Unlock, get in the car, and see if it starts.

 

May need to have your NOCO LOCO ready. Just wondering if there's something weird happening here. 

 

 

I'll try the cabin preconditioning later with the Battery monitor connected to see what is going on. In the meantime, I've made some observations in the pinned 12v Battery thread of what happens to the auxiliary Battery when the traction battery is charging.

[philip42h]

1 hour ago, nlee said:

I'll try the cabin preconditioning later with the battery monitor connected to see what is going on. In the meantime, I've made some observations in the pinned 12v battery thread of what happens to the auxiliary battery when the traction battery is charging.

I'm not sure that splitting the discussion across two threads necessarily helps ... 😉 ... but I think that so far you have demonstrated that:

• These Battery monitoring gizmos are not ideally suited to monitoring the state of the auxiliary Battery on the hybrid. The voltage data is OK, but it appears to be alerting you to the fact that the Battery may not be able to supply 300+ CCA to turn the starter motor that we don't have!
• The system does NOT charge the 12v auxiliary battery while the traction battery is on charge. But it appears to provide the 12v supply necessary while the charging is in progress - i.e. it should not be an additional drain on the auxiliary battery. I think ... And I suspect that one would hope that would be the case?

Either way, we don't yet fully understand what is going on ... 🙂

[nlee]

19 minutes ago, philip42h said:

I'm not sure that splitting the discussion across two threads necessarily helps ... 😉 ... but I think that so far you have demonstrated that:

• These battery monitoring gizmos are not ideally suited to monitoring the state of the auxiliary battery on the hybrid. The voltage data is OK, but it appears to be alerting you to the fact that the battery may not be able to supply 300+ CCA to turn the starter motor that we don't have!
• The system does NOT charge the 12v auxiliary battery while the traction battery is on charge. But it appears to provide the 12v supply necessary while the charging is in progress - i.e. it should not be an additional drain on the auxiliary battery. I think ... And I suspect that one would hope that would be the case?

Either way, we don't yet fully understand what is going on ... 🙂

I thought it would make it easier for anyone to find info on the Battery in the future on the Battery on the pinned post on 12v Battery maintenance rather than one titled such as this, once this discussion falls down the list of most recent.

On the first point, you can select the battery type in the settings for standard lead acid or AGM. I presume this just controls what the % reading is at specific voltages. There is also a custom option where you can set the voltage yourself for each 10% so you could set the curve up for any battery if you had the details or could work it out. There also seems to be an algorithm that "learns" over time but too early to say if that works well.

On the second point, I'd tend to agree on last night's observation. I did wonder if because it was reading 12.6v while I was driving last night, if it continued at that rate. No reason why it should but I'll monitor over subsequent charges.

[nlee]

15 hours ago, Nick72 said:

Wonder if anyone would be willing to try the following...

 

1. Set air con to off in the car. Yes, to off. 

2. Get out and lock the car.

3. Press the remote air con on the fob.

4. Leave it 5 or 10 min.

5. Unlock, get in the car, and see if it starts.

 

May need to have your NOCO LOCO ready. Just wondering if there's something weird happening here. 

 

 

I did a quick test for you @Nick72 this morning. For some reason I couldn't wake the car from the app this morning, maybe a signal issue but I pressed the button on the remote to turn the air conditioning on and monitored the Battery voltage real time.

The initial voltage was around 11.9v. on pressing the a/c button, there was an initial brief drop then you can see the voltage increases to around 13.4v, suggesting the traction Battery is providing power (and charging the battery). I'm sorry, I only had chance to leave it on briefly so I opened the door after about a minute and a half, the voltage dropped then increased slightly to stabilise similar to before. I'd assume the immediate drop before stabilising was due to other load coming on as I opened the door.

Next time I'll try it for longer and see if the traction Battery adds any charge to the 12v battery.

[robo1]

Don’t think it’s been mentioned in the thread but It would be interesting to know at what rate the traction Battery charges the auxiliary Battery. Anyone know ? 

[philip42h]

2 hours ago, robo1 said:

Don’t think it’s been mentioned in the thread but It would be interesting to know at what rate the traction battery charges the auxiliary battery. Anyone know ? 

An excellent question - and I certainly don't know the answer but it would be a very interesting number to know.

I read somewhere that an X Ah Y hr Battery should be capable of delivering X/Y amps for Y hours, and that the ideal charge rate was the very same X/Y amps. The Battery in the HEV is rated as 20hr, 45Ah so we would be looking at a charge rate of 2.25A. The Battery in the PHEV is rated as 20hr, 55Ah so we would be looking at a charge rate of 2.75A. 

The spec sheet for the Y6 batteries quotes charge currents as:

so 2.5A for the LN1 and 3.0A for the LN2.

Note that we know that our batteries are not (quite) Y6 series since the specs don't quite match - but they are similar ...

[ColinB]

On 11/1/2022 at 2:55 PM, philip42h said:

The wife has  a C-HR, isn't aware of the problem and doesn't need to be. We are both retired, have no regular commute and drive infrequently, irregularly or both. Looking back through the MyT data I managed to drive for a total of two hours in June (so less that 30 minutes per week) and the car was just fine - maybe I was just lucky ... 

🙂

I had a 2L C-HR previously and during lockdown the 12V Battery went flat twice, called out the AA the first time and had my portable Battery pack ready the second, so it can happen to those as well.....

[philip42h]

1 hour ago, ColinB said:

I had a 2L C-HR previously and during lockdown the 12V battery went flat twice, called out the AA the first time and had my portable battery pack ready the second, so it can happen to those as well.....

Yes, of course it can. During lock-down we had a pair of diesels - so beefier batteries - but I still put them on to trickle charge after a few weeks when I became aware of the potential issue - via this forum ... 👍

She has left her C-HR idle for well over two weeks without any problem - but I was ready, and half expecting to need to, give it a bit of a boost when we got back.

On a day to day basis it is generally a non-issue. As long as we are aware of the potential problem if we leave the cars idle for a longer period it is simple enough to be prepared and avoid getting caught out. But there are still a small number of 'anomalies' that it would be good to better understand ...

[Nick72]

8 hours ago, nlee said:

I did a quick test for you @Nick72 this morning. For some reason I couldn't wake the car from the app this morning, maybe a signal issue but I pressed the button on the remote to turn the air conditioning on and monitored the battery voltage real time.

The initial voltage was around 11.9v. on pressing the a/c button, there was an initial brief drop then you can see the voltage increases to around 13.4v, suggesting the traction battery is providing power (and charging the battery). I'm sorry, I only had chance to leave it on briefly so I opened the door after about a minute and a half, the voltage dropped then increased slightly to stabilise similar to before. I'd assume the immediate drop before stabilising was due to other load coming on as I opened the door.

Next time I'll try it for longer and see if the traction battery adds any charge to the 12v battery.

Thank you. That's interesting. I wonder if the remote air con start killed the Battery before the traction Battery had chance to come in and take over.

[ernieb]

11 hours ago, Nick72 said:

Thank you. That's interesting. I wonder if the remote air con start killed the battery before the traction battery had chance to come in and take over.

The 12v is certainly needed to control the starting and monitoring of the A/C heating system but the power for the heat pump if from the traction Battery. Nigel said above that once the A/C is pressed the 12v Battery voltage drops to 11.9v then recovered to 13.4v, that would be OK if the Battery was 100% charged but a volt low if it needed charging.

[Nick72]

11 hours ago, ernieb said:

The 12v is certainly needed to control the starting and monitoring of the A/C heating system but the power for the heat pump if from the traction battery. Nigel said above that once the A/C is pressed the 12v battery voltage drops to 11.9v then recovered to 13.4v, that would be OK if the battery was 100% charged but a volt low if it needed charging.

So this is what I'm still a little stuck on. The 12V Battery should have been at a good charge state given the amount of long runs I'd done. The traction Battery virtually full too.

I can understand an initial drop on the 12V as things power up but that shouldn't kill the Battery even if it was a little lower than normal SOC. Which it shouldn't have been. 

This is why I'm wondering if this is a system design issue. As I mentioned the Air Con was actually set to off prior to me pressing the Air Con button on the fob. I wonder if what happened here is there was no handover to the traction battery and instead it was doing something that was draining the battery.

I'm going to try this at the weekend. Couldn't afford the time this week to risk flattening the battery then faffing.

Must be key fob instructed air con start, air con must already be set to off inside the car. I have a sneaky feeling this may be an overlooked problem.

[ernieb]

1 hour ago, Nick72 said:

So this is what I'm still a little stuck on. The 12V battery should have been at a good charge state given the amount of long runs I'd done. The traction battery virtually full too.

I can understand an initial drop on the 12V as things power up but that shouldn't kill the battery even if it was a little lower than normal SOC. Which it shouldn't have been. 

This is why I'm wondering if this is a system design issue. As I mentioned the Air Con was actually set to off prior to me pressing the Air Con button on the fob. I wonder if what happened here is there was no handover to the traction battery and instead it was doing something that was draining the battery.

I'm going to try this at the weekend. Couldn't afford the time this week to risk flattening the battery then faffing.

Must be key fob instructed air con start, air con must already be set to off inside the car. I have a sneaky feeling this may be an overlooked problem.

Worth trying just maybe some events combining to give facilitate the problem.

[NASY]

Nick, I'll do what you want to try and give you another source this weekend. Step by step, exactly as you say and hopefully we can as a community get to the bottom of this. If it means we know how to avoid a design pitfall it may not fix the problem but at least non of us will fall foul of it. Bit like walking through a minefield - done it once, never again hopefully but give me the map.

[Nick72]

2 hours ago, NASY said:

Nick, I'll do what you want to try and give you another source this weekend. Step by step, exactly as you say and hopefully we can as a community get to the bottom of this. If it means we know how to avoid a design pitfall it may not fix the problem but at least non of us will fall foul of it. Bit like walking through a minefield - done it once, never again hopefully but give me the map.

Thanks. If there is some odd combination of states that causes this then at least we can all know to avoid it and avoid getting stranded somewhere.

[NASY]

Tried your 1 to 5 Nick. Car started just fine, so seems like an anomaly when you had the fail to start, not very reassuring really.

[ernieb]

Car this morning showed 14.3v charging, covered about 45miles, a couple of short trips in between 20miles ones, still showing 14.2v I’d have thought that would be more than enough to charge the 12v Battery?

[philip42h]

15 minutes ago, ernieb said:

Car this morning showed 14.3v charging, covered about 45 miles, a couple of short trips in between 20 mile ones, still showing 14.2v I’d have thought that would be more than enough to charge the 12v battery?

If the Battery were charging at 5A it would take 9 or 11 hours to charge from empty - depending on whether we are talking about a 45Ah HEV or 55Ah PHEV. But the spec sheets suggest that maybe 2.5A is more appropriate, so that would take the charging time from empty to 18 or 22 hours.

Of course you didn't start from empty, and with the hybrid system (HEV or PHEV) we are more concerned about time than distance, but we'd need to know how long the car had been standing idle before these trips (around 2 hours?) before we can guess whether or not your auxiliary Battery should have been full by the end ... 😉

[ernieb]

1 minute ago, philip42h said:

If the battery were charging at 5A it would take 9 or 11 hours to charge from empty - depending on whether we are talking about a 45Ah HEV or 55Ah PHEV. But the spec sheets suggest that maybe 2.5A is more appropriate, so that would take the charging time from empty to 18 or 22 hours.

Of course you didn't start from empty, and with the hybrid system (HEV or PHEV) we are more concerned about time than distance, but we'd need to know how long the car had been standing idle before these trips (around 2 hours?) before we can guess whether or not your auxiliary battery should have been full by the end ... 😉

Understand. I used the car yesterday and the 12v Battery was reading 12.4v when I switched it off so from that I’d assume it was charged. It was cool overnight 6oC, but I just got in and switched to READY mode, no pre heating. The last trip home took around 45mins and just over 20miles. I’d have hoped/expected the 12v Battery to be charged. 

[philip42h]

12 minutes ago, ernieb said:

Understand. I used the car yesterday and the 12v battery was reading 12.4v when I switched it off so from that I’d assume it was charged. It was cool overnight 6oC, but I just got in and switched to READY mode, no pre heating. The last trip home took around 45mins and just over 20miles. I’d have hoped/expected the 12v battery to be charged. 

Agreed - at least back to the state it was when you started. Toyota's guidance was 60 minutes in Ready mode per week to keep the Battery topped-up. That's a mere 10 minutes per day (between friends) and you'd been driving for well over 10 minutes ... 👍

No, I don't understand either ... 😉

[robo1]

41 minutes ago, ernieb said:

Understand. I used the car yesterday and the 12v battery was reading 12.4v when I switched it off so from that I’d assume it was charged.

But according to the charts the Battery was 80 % charged not fully charged  (unless your monitor under reads).I suspect the rate of charge from the traction Battery is a lot less than produced by an alternator causing some of the problems. 

 

[ernieb]

Agree with the chart but I’ve never seen it higher than 12.4v and I’ve checked the monitor with an AVO 10 I have to hand. I think the monitor is pretty accurate but at least it is relatively consistent. It was higher after I’d charged it with the NOCO but that figure didn’t last long. 

[robo1]

I tend to get similar readings. Like wise highest I’ve seen it was after a nights on charge following my flat Battery episode. It was 12.81v when tested at the garage. 
That’s why I wonder if the Battery never gets fully charged by the traction Battery for whatever reason.