Battery problem

[GPFFE]

I have a 2014 ford fusion energi. I went on vacation for 10 days over the Christmas break and left the car plugged in our non heated garage. In early January upon my return we got some cold nights in Toronto. My battery charging kept going down from 35 km to 31 to 28 to 26 whether I plugged in at home or the office (not in garage). However, I put it down to the extreme cold snap. On January 7 I got a red wrench while out driving while on my way to dinner. I parked at the restaurant and came out an hour later. The car would not start - even though I had gas and 12 km showing on my battery charge. I received a red triangle not to drive and call dealership. Start button would just flash green. I had it towed to the dealership. The dealership had it for 3 weeks as the part - the heater for the batteries was not working - they didn't have a part at ford and had to go directly to supplier and thus the lower km. I picked it up yesterday - yes they had it for 3 weeks which didn't sit well with me especially since I am leasing it. I plugged it in overnight last night and the battery only charged to 24 KM. My question is could the batteries be permanently damaged during the cold snap due to the faulty heater? Thank you.

[Russael]

No.  Cold won't damage our batteries, it just reduces their performance.  Hot temperatures are what actually damages them and reduces their service life.  That's why a few Leaf owners in AZ and other absurdly hot areas of the country have experienced actual battery capacity reduction.  I suppose very cold temperatures could damage a lead acid battery if that reaches a temperature where the electrolyte actually freezes, and then causes the case to burst or plates to crack.

 

I kind of wonder since your car was destined for Canada, that you actually DO have a battery heater.  We don't.  I've requested that Larryh monitor battery temperature during Go Times and the battery is not preheated.  They do slowly warm up while actually driving though.

 

Since they did some work to your car, your ride may now need to re-learn a bit of your commute to give you a proper estimate of your range.

[larryh]

There is no heater for the HVB.  The only way to warm it up is to charge it (raising temperature by at most 4 F) or draw power from it (much more effective).  The HVB temperature on my car has been as low as -10 F when left outside in the cold.  That does not damage the battery.

Edited February 1, 2015 at 12:30 AM by larryh

[garymkrieg]

So at what high temperature do we have to start to worry.  I usually spend part of the summer in Las Vegas.

 

Gary

[larryh]

The car will start reducing power output from the HVB to reduce any further rise in temperature when the HVB temperature reaches about 113 F

Edited February 1, 2015 at 04:30 PM by larryh

[Hybridbear]

The car will start reducing power output from the HVB to reduce any further rise in temperature when the HVB temperature reaches about 113 F

The Focus Electric has a liquid-cooling system which does not allow its HVB to exceed 98 F. I'm a little surprised that the Energi allows the HVB to get so much warmer.

[stevedebi]

The Focus Electric has a liquid-cooling system which does not allow its HVB to exceed 98 F. I'm a little surprised that the Energi allows the HVB to get so much warmer.

The FFE has to use active cooling because of the large battery pack - it generates too much heat. Ford had a lot of experience with the Escape Hybrid, which went from A/C battery cooling (2005 - 2009) to not running the A/C back to the battery pack (2010 - 2012). I think they used that experience to decide they could get by without the weight and energy penalties of active cooling in the Energi and conventional hybrids.

Edited February 3, 2015 at 05:39 PM by stevedebi

[Hybridbear]

The FFE has to use active cooling because of the large battery pack - it generates too much heat. Ford had a lot of experience with the Escape Hybrid, which went from A/C battery cooling (2005 - 2009) to not running the A/C back to the battery pack (2010 - 2012). I think they used that experience to decide they could get by without the weight and energy penalties of active cooling in the Energi and conventional hybrids.

You would think this, and this may be true in certain cases, but monitoring battery temps has shown that the Energi packs fluctuate way more in temp. Since the Focus Electric pack has a higher thermal mass it increases in temperature more slowly both from driving and from charging compared to the Energi HVB. The Energi HVB will often increase 10-15 degrees while driving and then cools down close to ambient temp while parked during the day (maybe from 75 F in the morning to 25 F in the evening). The Energi pack will then warm up to 75 F again by the next morning after being parked underground and charged. The Focus pack will start out maybe only around 55 F and it will cool down to the mid-30s during the day. Then the car heats it up to 50 F and it only warms up to about 55 F while charging overnight.