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Didn't know it was the 40 too. wow.
Yep. Took my 1 year old 40 in for a service and had the letter that morning - battery earth tags and s/w update for emergency braking, which Glyn Hopkins fitted in with the service (well done GH Bedford).
Then the dealer phoned me the following morning and sold me a new one. Ho Hum.
 

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When I had a 24, I just set it to that and then kicked off a fresh charge from my phone when I woke up in the morning so it would be at 100% when I'd finished breakfast.
It would take ~3 hours for my car to get from 80% to close to 100%. At 1:15, charging power starts to taper. I'd expect 2 hours for 6.6kW equipped cars. That's a very leisurely long breakfast ;)

I have Home Assistant automation to start at 3:30 to have the car at around 100% by 6:30 for me to drive to work. This way, if wife wants to use the car (she only drives a few miles, I drive 55-60 miles), I'd just turn off that automation. No need to go out to the car to change charge setting :D

LEAF has a fuse in the middle of series string of battery modules. If things go badly wrong the fuse will open. That splits the pack into two isolated sections.
Is this at the rear seats floor hump?
 

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Is this at the rear seats floor hump?
Yes. The fuse it is integral with the service plug.


Plug installed.
124637


Take it out, flip it over and there is the fuse.

124636
 

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So instead of 380-400 volts it's only 180-200volts whew..that's a huge relief!

Seriously, the bus bars must terminate at the electric motor, I wonder how well insulated they are when the vehicle is suddenlly totally submerged,
HV lines from the traction battery pack go to the to the Power Delivery Module(PDM). The DC-DC converter and the AC charger are inside the PDM. The PDM sits on top of the inverter. There is an internal DC bus connection between the PDM and the inverter. The inverter connects to the motor.

124638





There is a contactor in series with the battery. It is inside the pack. The contactor is double poll. It switches both + and -. When it is off, the pack is isolated from the rest of the car. It energised by a fused feed from the 12V system. Any short, electrical fault, collision or failure of the 12V system should open the contactor.

If the car is submerged and there is a HV short, the contactor will open, disconnecting the pack from the rest of the car. If that fails, the service fuse will open.
 

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It would take ~3 hours for my car to get from 80% to close to 100%. At 1:15, charging power starts to taper. I'd expect 2 hours for 6.6kW equipped cars. That's a very leisurely long breakfast ;)
I believe in a good breakfast. :)

I wake up about 6.30, so that is when I'd put it on for the extra charge. On a level 3.3kW that would be under 2 hours, and if it tapers at the end for cell balancing then that is only a small part of the capacity and not that worth worrying about. It works well as a process, honest.
 

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HV lines from the traction battery pack go to the to the Power Delivery Module(PDM). The DC-DC converter and the AC charger are inside the PDM. The PDM sits on top of the inverter. There is an internal DC bus connection between the PDM and the inverter. The inverter connects to the motor.

View attachment 124638




There is a contactor in series with the battery. It is inside the pack. The contactor is double poll. It switches both + and -. When it is off, the pack is isolated from the rest of the car. It energised by a fused feed from the 12V system. Any short, electrical fault, collision or failure of the 12V system should open the contactor.

If the car is submerged and there is a HV short, the contactor will open, disconnecting the pack from the rest of the car. If that fails, the service fuse will open.
Andrew, Thank you for this, it is an interesting explanation and the graphic clearly shows the integration of the various modules. So the double pole contactor is inside the battery pack, and isolates the battery from the rest of the car. Still doesn't help with water ingress into the pack itself through physical damage, but does put to rest other concerns.
This was just an enquiry about the safety of EV's and flood conditions that crossed my mind when watching the news footage of that Royal Mail depot full of semi-submerged red vans.
Thank you for your detailed reply, hope nothing ever happens close to the worst case scenario I envisaged.
Cheers, Tony.
 

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So the double pole contactor is inside the battery pack, and isolates the battery from the rest of the car.
Yes. There are two separate main contactors near the front of the pack. One is for + and the other for -. There is also a small one for the pre-charge test circuit. It in the centre of the photo.



124648
 

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Looks quite meaty, (especially from a video engineer's standpoint more used to smd's) but I wonder what the MTBF is for those contactors, must be a hell of an initial current draw when the car is switched on and the foot stamps on the pedal.....
 

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The leaf uses a NCM 523 battery cell. As with all lithium batteries a charge to 90% is best for longevity. The Battery Management System (BMS) ensures this happens (at least on the 30Kw Leaf) automatically, there really is no need for the owner to try and set this up for themselves.

I just plug mine in to the 7kw charger overnight unless I have done less than 20 miles the previous day or I need a full charge the following day. The BMS system takes care of the rest and stops when it is done.
I don’t understand what you say about the BMS ensuring the charge stops at 90% - does it?
 

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That is what a BMS is supposed and designed to do. The leaf is the same as all lithium battery systems, whether it's an e-bike a fork-lift truck or a vehicle. The electrical and chemical properties all share the same characteristics and BMS systems are designed to optimise charging and cell balancing-that is their function.
 

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I don’t understand what you say about the BMS ensuring the charge stops at 90% - does it?
The BMS is configured to charge Leaf Li-ion to 4.1v rather than 4.2v.

While I've never gone into turtle mode, the lowest I've seen voltage is 3.4v so the BMS is set to slow a usable range between 4.1v - 3.3v

NASA studies showed that charge to 3.93v provides the most optimum balance between number of cycles and usable capacity.

To not bore you to death, every 0.1v drop in max charge voltage doubles the number of cycles. Same goes with DoD.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

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People on here are pretty scathing with regard to the leaf's BMS and charging systems, but I confess I do not share many of their concerns. Unless the original design engineers are totally incompetent which I really find hard to contemplate; they would have to be on something a bit stronger than a bit of mull to stuff up such a critical part of the Leaf's engineering. After all it goes to the core and is the whole raison d'etre of an EV.

Although an electriconics engineer myself, these design guys are on a totally different level of intellect and knowledge to we more humble mortals. I am a firm believer in the original designers know the product far more intimately than I and they set the working parameters of the circuitry the way they do for very good reasons. In my working life I have very rarely found the need to modify original circuitry to something I consider better, and then usually only because a better component has come to the market.
 

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People on here are pretty scathing with regard to the leaf's BMS and charging systems, but I confess I do not share many of their concerns. Unless the original design engineers are totally incompetent which I really find hard to contemplate; they would have to be on something a bit stronger than a bit of mull to stuff up such a critical part of the Leaf's engineering. After all it goes to the core and is the whole raison d'etre of an EV.

Although an electriconics engineer myself, these design guys are on a totally different level of intellect and knowledge to we more humble mortals. I am a firm believer in the original designers know the product far more intimately than I and they set the working parameters of the circuitry the way they do for very good reasons. In my working life I have very rarely found the need to modify original circuitry to something I consider better, and then usually only because a better component has come to the market.
Nope. It's a balance between cost and performance. Engineers and technicians can advice - most of which is ignored in real world by management.

The fact that 3rd gen Leaf still doesn't have thermal management proves it beyond doubt.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

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People on here are pretty scathing with regard to the leaf's BMS and charging systems, but I confess I do not share many of their concerns. Unless the original design engineers are totally incompetent which I really find hard to contemplate; they would have to be on something a bit stronger than a bit of mull to stuff up such a critical part of the Leaf's engineering. After all it goes to the core and is the whole raison d'etre of an EV.

Although an electriconics engineer myself, these design guys are on a totally different level of intellect and knowledge to we more humble mortals. I am a firm believer in the original designers know the product far more intimately than I and they set the working parameters of the circuitry the way they do for very good reasons. In my working life I have very rarely found the need to modify original circuitry to something I consider better, and then usually only because a better component has come to the market.
I often alter wiring or make modifications to machines as everyday use highlights shortcomings in the original design. Often down to the designers not factoring in the inherent gift of individuals to do things that defy the logic of intelligent beings.

I am in fact doing such a modification this morning.

But I totally accede to the vastly superior intellect of the BMS engineers.
5 years in and I simply just get on with it.
 

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What is considered to be a cycle? Is it from top to bottom or a small top up to get you home?
A full cycle is a full discharge from fully charged state to fully discharged state.

4.2v => 3.0v

A li-ion cells has a cycle like of around 400 cycles before capacity degradation his 80%.

The reduction at top and bottom is to extend to time before degrading 80% since you end up with a mini cycle.

Micro cycles further improve the usable life.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

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Discussion Starter #57
A full cycle is a full discharge from fully charged state to fully discharged state.

4.2v => 3.0v

A li-ion cells has a cycle like of around 400 cycles before capacity degradation his 80%.

The reduction at top and bottom is to extend to time before degrading 80% since you end up with a mini cycle.

Micro cycles further improve the usable life.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
Thanks. So my idea at the top of this thread is more positive than negative and it certainly fits in with my habits.
 
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