Cold Weather Battery Issues

[BarryW]

Hi All-
Recently I leased a B Class ED and live in Northern New England. Our arctic cold has been seriously impacting the battery range- both in terms of its availability for electricity charging and the impact on mileage. I have no garage but am leasing one and looking for options on how to heat the battery remotely. The battery is insulated from the passenger compartment so well the dealer does not think pre-heating will help much. Anyone use a space heater? Other options welcome!

Regards,
BarryW

 

[bcurious]

Barry -
I share the cold weather problem regarding range, but the availability problem I don't understand unless the charge station availability falls outside your reduced range. What I wonder is if heating the battery while the vehicle is parked is actually helpful in doing anything but increasing the estimated range displayed within the vehicle before departure. If so, it seems that M-B might have just built in a battery heating system for use while plugged into a suitably powerful source.
Scheduling the climate control to bring the interior up to temp before disconnections seems to add about 2 miles to the range per charge, which is something but not terribly significant. The range savings is due to keeping the charge in the battery instead of using it to produce heat in the interior, not due to the warming of the battery. We're finding that my wife's commute works best (for the B-Class) as a multi-modal commute wherein she can leave the car at a chargepoint location during business hours. That is a solution for commuting, but not a solution for preserving B-class range in cold weather. We are expecting results in improving charging infrastructure rather than range extension of the B-Class in the cold. Best of luck to you, I can imagine that your location is substantially more challenging than mine for an EV of typical storage capacity.

 

[JeffRay]

Well, later today, I go get my MB-Be from the outdoor garage where it has been sitting since December 23rd. That would be 26 days by my count. It had a full charge when I left it and we shall see what it has having depleted presumably sitting for about a month but outside where the average temperature has been 20-40 degrees. Back with a report later.

 

[BarryW]

I drove 2011 and 2012 Nissan LEAF versions collectively over 24k miles in the Northwest, which gets cold but clearly not like Maine. The impact on the B Class battery here seems very harsh, especially given my expectations of the larger battery. Now, I only just got it and I am playing with solutions but Mercedes does need a cold weather design for this issue as even the dense deployment of public charging won't solve this (who wants to go 30 miles and charge for an hour?). I have been reading about the Farnum Battery heater pad product which might be placed underneath the vehicle to keep the battery pack warmer- however I do not know if that really solves the issue as the battery will chill down rapidly when out and about. It may allow a higher state of charge (and greater range access) for a while but after the ambient temp drops, I don't know. I'm not an engineer and it will take me some experimentation to see if this offers any practical advantage.

Thanks for your replies. I love the car but... I need it to perform better.

 

[mikegerard]

I can share some insights from my RAV4EV last winter and this winter. I'm near Rochester, NY so the climate is somewhat similar.

You will lose range in the winter...no way around it. Once you start using the heater the GOM is totally useless. Your total range will drop 30+% but your bunch of short trips range will drop even more (because you need to heat up the battery and interior multiple times).

Best practice is to have a way to charge at your destination. Charge and preclimate right before you leave. Even if you are not fully charged you have warmed up the battery which is good.

Your efficiency will be all over the place depending on how much heat you are using. In the summer I can average 3.3-3.5 miles/kwH. In the winter I can get 3 with the heat off but in stop and go traffic with the heat blasting and only a couple miles of travel I can get as low as 1 (and usually average about 2.2).

My wife uses the car most of the time. Unfortunately she has no way to charge or warm up the car at work. Even a 110 plug would be a big help here as you could preclimate and warm the battery at least before you head out. I know that sounds inconvenient but our friends up north have to use engine block heaters in the winter so they can start their gas cars.

Mike

 

[JeffRay]

Well, a very unscientific test but after letting the car sit for 26 days outdoor with a full charge, I retrieved it Tuesday and it read 80+ percent charged. I am sure that some of the loss was the garage guys moving the car around but the rest was battery drain sitting in cold weather. As a result, tomorrow, I go straight to the dealer to recharge while I am at work and pick up after work.

 

[TonyWilliams]

A heat pack on the battery would be near useless. Instead, heat the battery with the onboard equipment that it already has (the cells are robustly heated and cooled every time it charges, is ON / READY, or when you use the pre-climate / pre-condition.

If you can plug in, even 120 volts, and drag the charge out until your departure time, the battery will be heated.

 

[mikegerard]

A heat pack on the battery would be near useless. Instead, heat the battery with the onboard equipment that it already has (the cells are robustly heated and cooled every time it charges, is ON / READY, or when you use the pre-climate / pre-condition.

If you can plug in, even 120 volts, and drag the charge out until your departure time, the battery will be heated.

I have not tried it personally but I think plugging it in at 120 during the day would work great. The battery will be heated when you leave. Better of course would be level 2 charging and then running a preclimate but it's a lot easier to find 120 at work than level 2.

Mike

 

[Anonymous]

Have owned the car for two weeks, have about 100 miles on the car all local driving. Temps in the low 30's. Seemed like everyone else I am having disappointing range. Everything from 1.2mpkw to 3.1mpkw.
Then just took a 35 mile drive to work/35 mile return trip. On the first leg used 33% of battery from 100% (forget even using the unreliable Guess-O-Meter).
Return trip usage only 31% after full recharge back to 100% at the office.
Simple math tells me I could get a 100 mile range. Pleasantly surprised.

Driving mode settings and driving style- E/D/20 miles hwy/15 miles local/No paddle use at all/% of battery actually increased along the way through braking regen. Probably got back about 6% during the drive getting me to the net usage of 33% as stated above for each segment.

Loving the car!

 

[mddg]

I have had a similar experience - much better range than usual for the temperature for the past two days. Around 30-34 degrees F in the wintry mix of snow and rain around the DC area, I have gotten around 85-90 mile range. In the previous few weeks, I would have expected around 70-75 mile range at 30 F. I think that's partly caused by driving more slowly than usual - 45-55 instead of 55-65 mph, little traffic - so few stops and starts, and driving more conservatively with a very gentle accelerator pedal touch, almost never exceeding the second tick mark on the power usage dial. Also no climate control, just the seat warmer.

I did get an unusual warning message along the lines of something like "Radar sensor need cleaning. Please consult manual." I couldn't find anything like this in the manual, so I'm not absolutely sure where to clean. I think it may be under the hood behind the logo in the grill. Has anyone seen this? I didn't get it today, so it might be the road spray yesterday.

 

[sendler2112]

The front sensor looks out through the star. The rear sensors look out through the sides of the rear bumper. You can get that message if slush or mud starts to build up.