Cold Weather Package Features

[dgpcolorado]

It seems that either we don't have good data on the battery heaters, or they are programmed different in Canada. Here's what Nissan Canada says:
Also, it works all the time; whether the car is operating, or plugged in, or not.

It cant be like that, otherwise you would drain your battery over a few days parked anywhere in Winnipeg in winter.

You over estimate how much power it takes to heat the pack up and how well it retains heat.

That is the same as the manual for USA cars. The battery heater is reportedly 300 Watts and will draw from the traction battery down to 30% charge. If the car is going to be left for an extended period at very low temperatures Nissan recommends leaving it plugged in.

But, with 80% charge one would have (80%-30%) x 21 kWh = 10.5 kWh to use for heating. That's about 35 hours worth if it ran continuously, not counting other drains on the system. My take on all this is the car could last for several days at low temperatures even when not plugged in. I was concerned because I will need to transport my LEAF next month and a cold snap in Idaho and Utah is possible.

From the 2012 LEAF manual:

LI-ION BATTERY HEATER

CAUTION
The Li-ion battery heater does not operate if the available Li-ion battery charge is less than approximately 30% and the charger is not connected to the vehicle. To help prevent the Li-ion battery from freezing, do not leave the vehicle in an environment if temperatures may go below -4ºF (-20ºC) unless the vehicle is connected to a charger.

The Li-ion battery heater helps to prevent the Li-ion battery from freezing and helps to prevent significant reductions in the Li-ion battery output when the temperature is cold. The Li-ion battery heater automatically turns on when the Li-ion battery temperature is approximately -4ºF (-20ºC) or colder. The Li-ion battery heater automatically turns off when the Li-ion battery temperature is approximately 14ºF (-10ºC) or higher.
The Li-ion battery heater uses electrical power from an external source when a charger is connected to the vehicle. The Li-ion battery heater uses electrical power from the Li-ion battery when the charger is not connected to the vehicle.

NOTE:
• Connect the charger to the vehicle and place the power switch in the OFF position when parking the vehicle if temperatures may go below -4ºF (-20ºC). This provides external power to the Li-ion battery heater when it operates and does not discharge the Li-ion battery.

• The charging status indicator lights illuminate in a specific pattern when the Li-ion battery heater operates. The charging status indicator lights use the same pattern to indicate 12-volt battery charging, Climate Ctrl. Timer operation or Remote Climate Control operation. The charging status indicator lights do not change if the Li-ion battery heater operates at the same time as the above features. See “Charging status indicator lights” in the “CH. Charging” section.

•The Li-ion battery heater uses Li-ion battery power to operate, even if the vehicle is connected to a charger when:
— the vehicle’s power switch is in the ON position.
— there is no electrical power being supplied to the charging equipment.

• When the Li-ion battery heater is already in operation using an external power source, it will continue to use the external power even if the power switch is placed in the ON position.

• Vehicle driving range is reduced if the Li-ion battery heater operates (Li-ion battery temperature approximately -4ºF (-20ºC) or colder) while driving the vehicle. You may need to charge the Li-ion battery sooner than in warmer temperatures.

• The Li-ion battery requires more time to charge when the Li-ion battery heater operates.

• The predicted charging time displayed on the meter and navigation system increases when the Li-ion battery heater operates.

• Climate control performance is reduced when using the Climate Ctrl. Timer or Remote Climate Control while the Li-ion battery heater operates.

• The Li-ion battery may not charge to the expected level using the charging timer when a [Start Time] and [End Time] are set while the Li-ion battery heater operates.

• Set only the charging timer [End Time] when charging in cold weather. The vehicle automatically determines when to start charging to fully charge the Li-ion battery, even if the Li-ion battery heater operates. Charging ends before the set end time if the Li-ion battery is fully charged. [Page EV-5]

 

[McDavis]

I'm so disappointed that we don't have the CWP, now. Damn you, Southern California! I was lost on finding anything...I swear that these search controls send me on wild goose chases every time.

That's what we get for buying a used LEAF. At any rate, I will be driving mine in -3 degrees tomorrow unless the battery packs freeze over night. I'll search for some sort of heater for the garage with the search feature.

 

[abasile]

At any rate, I will be driving mine in -3 degrees tomorrow unless the battery packs freeze over night.

My understanding is that you'd need temperatures lower than that, for a significant period of time, before the pack freezes. Also, it has been my experience that driving will help warm a cold pack. Buy an aftermarket seat warmer, and wear gloves, and you should be fine.

 

[McDavis]

I live in CO. I know how to stay warm, thanks! I just meant that the car was from Southern California, where people don't understand "seasons."

 

[TonyWilliams]

The battery won't "freeze" until -30C. There are lots of simple concepts to keep the battery warm. The colder the battery, the lower the capacity.

Your range is going to seriously suffer when you run the heater. You might consider having a shop put in seat heaters to more energy efficiently stay warm, and keep the heater off as much as possible.

The cold will affect the battery capacity in two ways; losses from the battery itself being cold, at about 1% reduction in capacity per 2F below 70F. At minus 3F, that about 36.5% reduction in capacity.

The second is your heater use. Find ways to preheat the cabin and battery, and stay away from the heater as much as possible.

 

[Herm]

I At any rate, I will be driving mine in -3 degrees tomorrow unless the battery packs freeze over night. I'll search for some sort of heater for the garage with the search feature.

get a magnetic stick on oil pan heater for ICE cars.. the battery case is steel.

http://www.amazon.com/Kats-1153-Handi-Heat-Magnetic-Heater/dp/B000BOABS6" onclick="window.open(this.href);return false;

 

[abasile]

I live in CO. I know how to stay warm, thanks! I just meant that the car was from Southern California, where people don't understand "seasons."

Depends on who you talk to in SoCal. Where I live in SoCal, we've had snow on the ground, to a greater or lesser extent, for the past month. It's not quite as cold as your current weather, though.

 

[muus]

get a magnetic stick on oil pan heater for ICE cars.. the battery case is steel.

I often see this suggestion posted here and there. I STRONGLY recommend you DO NOT use this to heat the battery. These magnetic heaters apply 200W of heat on a very small area (only a few square inches). They are intended to heat the oil in a ICE oil pan. The oil is fluid and can circulate (like warming water on a stove) and oil can sustain temperatures well above 200F. I don't think there really is any practical method of heating the batteries externally except for heating your garage. The only option I would see is to glue an electric blanket to the entire underside of the battery with an inch of insulation. Not very elegant and would be easily ripped off when driving through snow.

 

[TonyWilliams]

I don't think there really is any practical method of heating the batteries externally except for heating your garage.

Heating the entire garage is practical?

Run any kind of heater on the battery that you want, just don't let it get too hot (100 degrees would be my personal limit).

The oil pan heaters are too hot, that's true. Obviously, it fairly simple to ramp down the amount of heat they produce, and those pads are nicely durable compared to electric blankets. They won't hold moisture like a blanket, causing corrosion. Any insulation that you use around the heating pads should not hold moisture.

 

[Herm]

Stick it to a plate of steel and see how hot it gets..

Its a legitimate fear but these magnetic heaters are not very powerful.. you could also stick it on the body of the car itself, next to the battery pack.. but I doubt it will do anything useful.

From the battery pack pictures, it appears there are empty spots with no cells in forward centerline of the car, where the safety fuse is and forward.. the one accessible from the rear seats.

 

[TonyWilliams]

Here's a service manual diagram where the factory heaters are. Number 7 in the diagram is the heater controller. Remember, this system only comes on at -20C, and turns off at -10C, at 300 watts.

Heating the battery externally would presumably be to a much higher temperature, up to about 100F/40C.

 

[muus]

Heating the entire garage is practical?

Depending on the situation, yes. A little insulation goes a long way. I don't heat my garage but it is well insulated and even when it's -15F outside, the temperature in my (attached) garage never dips below 41F. It doesn't need to be 70F. It may not always make financial sense (especially if you don't have a garage) but trying to heat a battery pack that spans the width and nearly half the length of the car by heating only a few square inches won't help. At best it will waste a few hundred Watt hours, at worst it will overheat and damage the cells immediately above the magnetic heater. In order to properly heat the batteries, heat has to be applied uniformly across the entire surface of the battery pack and never exceed about 100F (I'd play it safe and stay below 85).

 

[Herm]

but trying to heat a battery pack that spans the width and nearly half the length of the car by heating only a few square inches won't help. At best it will waste a few hundred Watt hours, at worst it will overheat and damage the cells immediately above the magnetic heater.

I think you guys are overestimating the damage a 200w heater can do to a 400lb battery pack covered in thick gauge steel.. all the modules are in contact with each other to help dissipate the heat and those flat cells are excellent conductors of heat. There are lots of places in that pack that the heater would not be close to any cells.