V37 Hybrid stuff: Low Speed

[CucumberError]

Following on from something that sonicii posted in another thread about towing with a V37 hybrid, I recently had an issue with mine, and thought I'd share.

As someone else worked out, I'm not in Australia, I'm in New Zealand. A the end of August I did a road trip around the south island. Started from home in Wellington, jumped on the ferry to the South Island (Bluebridge), drove down to Christchurch, a bit of time there, down to Dunedin for some family stuff, then back up to Christchurch of the night, Picton, and got the ferry back to Wellington. Amazing road trip, a heap of fun. The cruise control + active lane control + all the other sensors made it pretty much self-drive along the Canterbury Plains. I love driving in the South Island so much more than the North Island. The car went amazing, other than 'the issue'.

On the return ferry trip back to Wellington, we looked around Picton, then driving through the port slowly, the car was running on batteries the whole time, so by the time we got to the ferry, the batteries were pretty much flat. Once we start driving up the ramp onto the ferry, the tread on the car ramps is very rough, and my poor sports suspension wasn't a fan of it, so we're driving pretty slow. Then we're directed up to the top deck, which has a pretty long, steep ramp, up past the other decks, all the way to the outside of the ship. By this stage, we're going about 2kmh, batteries are flat, car is doing that odd 'labouring the petrol engine while running on electric' that it sometimes does on the motorway on ramp in heavy traffic. As we're getting to the top of the big ramp, a caution light comes on, the display in the dash tell us that the hybrid system has over heated and we need to stop. At this point we're about 5m from the top of the narrow ramp, so all we can really do is keep going. About 5 seconds after we get to the top of the ramp, the warning lights went away, the message is gone, and everything is fine.

Now, what sonicii posted is "These cars don't have a torque converter in the transmission and rely on the low/reverse brake to act as a clutch at very low speeds (lower than idle speeds in 1st gear) and they don't like to slip for extended periods." I'm guessing that for that low speed it's actually just charging up the battery, using 100% electric for moving the car, and I can see how doing that for 5+ minutes constantly would cause things to heat up pretty quickly. Add in low air movement, and being inside a ship, this all starts to make sense.

When we headed south on the same ferry, we were on a lower deck, and were running on the electric motors for a shorter period that I don't think we ran into that issue. I've since worked out that if I leave the car in Standard, slide the transmission into tiptronic mode it pretty much makes the petrol engine behave as a stop start mode, meaning that the low speed in the dock would have used the petrol engine, so the batteries had some juice in them once we got into the ship. Also opening the drivers door with the car running starts petrol engine, but will only charge the batteries up to 50% and then stop the petrol engine; while waiting to disembark, I had the door open to charge the batteries back up. 

[Duncan]

Hey Darryl, noting I have a HY51 Fuga not V37, but I think it is pretty much the same system.

I've never had any issues with slow speed stuff, under load or not.  In mine the engine starts before the battery is flat under any condition, and it does so smoothly.

I haven't checked putting it in tiptronic to start the engine, but mine does not start when I open the driver's door.  I wonder if there is some voltage drop affecting your system (noting the 12v and HV systems are not really directly related, but it is possible a 12v drop is affecting the HV control system)

So, not sure how many other people can add an experience here @Fijay @sonicii

[sonicii]

I have to drive up a fairly decent ramp to get to my work car parking bay ,I just move the selector across to manual so it stays in 1st gear while climbing the ramp, it keeps the ICE running and RPM high enough that the clutch pack in the transmission never needs to slip while under the load of climbing up an incline.

ICE is always running when you have the transmission in manual mode, except when completely stopped.

Are you sure the temp warning was the electrics and not the transmission fluid temp (it might call it all 'hybrid system')?  But I wouldn't be too worried, highly unlikely you have damaged anything.

If I ever had to climb a ramp very slowly (sub 5km/h), I would probably just stop and wait for the car in front to get near the top, then select manual mode on the transmission and complete the climb at around 10km/h in 1st gear so nothing needs to be slipping.

Regarding the battery level, I notice it does tend to prefer to run on electric alone when puttering around at low speed, even when the battery level is fairly low, but it won't let it go under 20% before it starts the ICE and charges the battery again.

Also, these can never just use the ICE to charge the battery while only powering the wheels with the electric motor, as the motor is also the generator and it is all connected in series with a dry clutch (between the engine and electric motor) while the ICE is running, so it would be using the ICE to both charge the battery and drive the car.

I have also noticed the ICE starts when I open the drivers door, I am not sure of the reason for this, maybe it is some kind of extra 'warning' you have left the car on when you try to get out, for those people that ignore the 'dinging' sound?

Edited October 6, 2023 by sonicii

[Duncan]

Interesting, I'm surprised the Fuga behaves differently, although it is older, 2012 model

[Rocker]

Hi Duncan,

I had general query, I have been looking to buy 2011 NISSAN FUGA HYBRID, been doing some research. Idon't have gppd knowledge about this car. As you have used 2021 nissan fuga with your experience is this car reliable and have you had any issues with hybrid system?

 

[Duncan]

Hi mate, there are a couple of other hybrid owners here who can share their experience too. One thing before buying an old hybrid (as I did), you should get the battery voltages checked before you buy as it is a $5K+ to replace the battery (plus the difficulty of getting a battery from Japan to Aus, assuming that is where you are). Consult or other good scan tools can check the battery voltage when fully charged.

My experience with the hybrid has been excellent; between both motors it is a suitably quick car (280kw) for my daily use and the car itself is super comfortable and has all luxury toys you would expect from Nissan's flagship at the time, plus it was very good value (I paid about $30k for mine)

However....having said that, I have had a major issue with the hybrid system and as a result mine has been off the road for months, mostly because I have another car and don't work on fixing it every day. Basically I got hit in the rear coming onto the freeway and the car spent a while at the smash repair. When they were finished it would not start, turns out the 12v battery had died (potentially crash damage), then the hybrid battery kept trying to charge it until it was flat too, at which point it didn't have enough power to start the engine to recharge the battery and I was stuck. 

I'll post up the full story (once it is finished), but in summary I had to remove the pack and charge it manually, and had some (user error) problems doing that

So.....100% I would still buy the hybrid, they are great value for the price, but there is some risk involved due to lack of local nissan/infiniti support

[sonicii]

I would agree with Duncan, although I have the Q50 Hybrid, the drivetrain is pretty much identical.  I haven't had any issues at all with mine, it is a 2015 model and I have owned it for just over 3 years now.

My local Nissan dealer won't touch it, I asked them if they can do a DAS wheel alignment (not sure if DAS was on the Fuga), and they just refused, saying they don't know anything about working on Infinitis, so no way would they be interested in touching the hybrid system.

If you happen to live somewhere near one of the ex-infiniti dealers/workshops, they will probably more willing to help.

@Duncan what battery is $5k?  maybe the Fuga pack is different, but for the Q50, the complete battery pack is about $12k from Japan, or an individual cell module is around $1,200.  Although once the car is a few years, Nissan recommend replacing the entire battery pack if you have a module fail.

[Duncan]

I hadn't considered buying new they are reasonably well available through yahoo japan for late model examples...I'm sure they will be the same between the 2 models.