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KyDave95
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This is probably an easy question for some of the technical experts on this forum, but it's something I've always wondered about, and a Google search didn't quite answer my question.
If someone has to park a hybrid vehicle in a hot climate, what impact (if any) could that have on a NiMH or Li-ion battery pack? I've never owned a hybrid vehicle, but I've had vehicles that were parked in the Tampa sun for six hours or more in the middle of July, and those interior temps can get downright awful. Does the battery in a hybrid vehicle need any special consideration in a situation like that?
Window tinting, using sunshades, or leaving the windows cracked open are possibliities to help slow interior heat buildup, but on a warm and sunny day, a vehicle interior can still get ridiculously hot...
Thanks,
Dave
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danielgr
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I guess there could be a limit on what you call hot, but within the heat we have in Japan or Spain I've never experienced anything to care about with any of my hybrids.
Most manufacturers do extensive real world testing of their cars in all kinds of whether / desserts (on top of lab data), so I don't think there is much you would worry about.
That said, batteries don't play nice with extreme weather, so you tend to lose some of your FE when going to the extremes.
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owequitit
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KyDave95 wrote:
This is probably an easy question for some of the technical experts on this forum, but it's something I've always wondered about, and a Google search didn't quite answer my question.
If someone has to park a hybrid vehicle in a hot climate, what impact (if any) could that have on a NiMH or Li-ion battery pack? I've never owned a hybrid vehicle, but I've had vehicles that were parked in the Tampa sun for six hours or more in the middle of July, and those interior temps can get downright awful. Does the battery in a hybrid vehicle need any special consideration in a situation like that?
Window tinting, using sunshades, or leaving the windows cracked open are possibliities to help slow interior heat buildup, but on a warm and sunny day, a vehicle interior can still get ridiculously hot...
Thanks,
Dave
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I grew up in one of the hottest places in the western hemisphere and never heard of any issues. First, the interior is a greenhouse and the batteries aren't in the interior. I am sure there are some definite efficiency losses, but I haven't heard of major battery issues. I can tell you that it shortens the life of Lead Acid batteries by a significant amount.
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eneka
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Most EVs now a days have active cooling and will cool the battery if the temperature is too hot. Some BEVs have passive cooling like the leaf which many ended up with javily reduced range because the hot asphalt was essentially cooking the batteries.
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Nick GravesX
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Parked on a lot day is less likely to be an issue than driving like a lunatic on a hot day.
The constant cycling heats up the batteries from the core - notice how they become warm when you charge them? Even this Dell laptop refuses to charge if I've been using it out in the sun due to a temperature protection device.
This is part of the reason for the move towards nanotech anodes - there is a limit to charging speeds and it's why regen braking is currently so feeble.
Most batteries lose charge in the cold, which is why many have heating devices, too.
Currently, the only infernal combustion engine that duffers is Diesel, but the fuel only substrates at temperatures that would kill a battery.
But Teslas work in CA and Norway, so it's probably not too much of an issue.
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qingcong
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I'm not sure if the battery gets hotter during spirited driving or if the car is sitting in the hot sun. Either way I think they'd implement a thermal management system that either cuts back on power and/or turns on some cooling mechanism.
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CarPhreakD
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Not sure about all hybrids, but in BEVs most vehicles have either a coolant or AC based thermal management system. I think most hybrids are less concerned because they use more robust battery chemistries (ye' old NiMH) and those batteries aren't typically stressed as heavily via charging or discharging.
As far as in a static scenario where you're mostly concerned about heat conduction from the road or ambient temps, there are also limits- but unless you live in like, Arizona or Alaska, you won't likely hit them. For example, the ubiquitous (for Tesla) Panasonic Lithium Ion battery has a pretty wide latitude for storage temps. On this same datasheet you can see discharge characteristics, and specifically how detrimental cold temperatures are to battery function.
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KyDave95
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danielgr wrote:
I guess there could be a limit on what you call hot, but within the heat we have in Japan or Spain I've never experienced anything to care about with any of my hybrids.
Most manufacturers do extensive real world testing of their cars in all kinds of whether / desserts (on top of lab data), so I don't think there is much you would worry about.
That said, batteries don't play nice with extreme weather, so you tend to lose some of your FE when going to the extremes.
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Yeah, I'd always heard that hybrid fuel efficiency can take a hit in extreme weather, but I'd never really seen any discussion about whether or not temperature extremes could affect battery health...
Thanks!
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KyDave95
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owequitit wrote:
I grew up in one of the hottest places in the western hemisphere and never heard of any issues. First, the interior is a greenhouse and the batteries aren't in the interior. I am sure there are some definite efficiency losses, but I haven't heard of major battery issues. I can tell you that it shortens the life of Lead Acid batteries by a significant amount.
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This is something I've also been curious about. On the new Insight, for example, I read that the battery is located under the rear seat. So does that mean that even though it's technically "under there" somewhere, it's actually not really part of the car interior, and therefore service techs would access the battery from underneath the car?
Thanks!
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KyDave95
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Nick GravesX wrote:
Parked on a lot day is less likely to be an issue than driving like a lunatic on a hot day.
The constant cycling heats up the batteries from the core - notice how they become warm when you charge them? Even this Dell laptop refuses to charge if I've been using it out in the sun due to a temperature protection device.
This is part of the reason for the move towards nanotech anodes - there is a limit to charging speeds and it's why regen braking is currently so feeble.
Most batteries lose charge in the cold, which is why many have heating devices, too.
Currently, the only infernal combustion engine that duffers is Diesel, but the fuel only substrates at temperatures that would kill a battery.
But Teslas work in CA and Norway, so it's probably not too much of an issue.
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I try to drive with a gentle foot for the most part, especially in hot weather! But I do tend to run air conditioners at full blast for a while on really hot days, so could heavy AC usage make life more difficult for a hybrid on a really hot day?
Thanks!
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KyDave95
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CarPhreakD wrote:
Not sure about all hybrids, but in BEVs most vehicles have either a coolant or AC based thermal management system. I think most hybrids are less concerned because they use more robust battery chemistries (ye' old NiMH) and those batteries aren't typically stressed as heavily via charging or discharging.
As far as in a static scenario where you're mostly concerned about heat conduction from the road or ambient temps, there are also limits- but unless you live in like, Arizona or Alaska, you won't likely hit them. For example, the ubiquitous (for Tesla) Panasonic Lithium Ion battery has a pretty wide latitude for storage temps. On this same datasheet you can see discharge characteristics, and specifically how detrimental cold temperatures are to battery function.
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Ooh, an actual data sheet...thanks! I'll take a closer look at it when I get back to the house...
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Nick GravesX
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KyDave95 wrote:
Nick GravesX wrote:
Parked on a lot day is less likely to be an issue than driving like a lunatic on a hot day.
The constant cycling heats up the batteries from the core - notice how they become warm when you charge them? Even this Dell laptop refuses to charge if I've been using it out in the sun due to a temperature protection device.
This is part of the reason for the move towards nanotech anodes - there is a limit to charging speeds and it's why regen braking is currently so feeble.
Most batteries lose charge in the cold, which is why many have heating devices, too.
Currently, the only infernal combustion engine that duffers is Diesel, but the fuel only substrates at temperatures that would kill a battery.
But Teslas work in CA and Norway, so it's probably not too much of an issue.
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I try to drive with a gentle foot for the most part, especially in hot weather! But I do tend to run air conditioners at full blast for a while on really hot days, so could heavy AC usage make life more difficult for a hybrid on a really hot day?
Thanks!
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A/C consists of a pretty constant load, probably equivalent of about 5 BHP.
In terms of the ~100 BHP you may be demanding/not demanding. it's not really significant.
The problem with miserable winters is you're running lights, wipers, A/C or Heat pump, seat heaters etc plus frictional losses from standing water/pissing rain. Then it may add up to be significant if you are getting low on charge.
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JeffX
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KyDave95 wrote:
CarPhreakD wrote:
Not sure about all hybrids, but in BEVs most vehicles have either a coolant or AC based thermal management system. I think most hybrids are less concerned because they use more robust battery chemistries (ye' old NiMH) and those batteries aren't typically stressed as heavily via charging or discharging.
As far as in a static scenario where you're mostly concerned about heat conduction from the road or ambient temps, there are also limits- but unless you live in like, Arizona or Alaska, you won't likely hit them. For example, the ubiquitous (for Tesla) Panasonic Lithium Ion battery has a pretty wide latitude for storage temps. On this same datasheet you can see discharge characteristics, and specifically how detrimental cold temperatures are to battery function.
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Ooh, an actual data sheet...thanks! I'll take a closer look at it when I get back to the house...
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-20C to 50C
that's -4F to 122F.
I've approached or surpassed both extremes this calendar year.
Car interiors routinely soar above 60C in the summer here in the south - not sure how much of that radiates to the batteries after hours of sitting outside. And we were in West Virginia (and Kentucky) earlier this year and it was -11F overnight while we were there. The datasheet doesn't say what happens to those cells when the storage temp ranges are exceeded but it's not difficult to find places in the US where you'll test those limits.
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TonyEX
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I've driven my hybrids (06 IMA, '14/'5 iMMDs) in 110F/30F weather with no loss of efficiency.
If you're interested in what really kills efficiency: aerodynamics and rain.
(1) Rain. The wet pavement increases the rolling resistance of your tires. I've seen as much as a 10% decrease in efficiency.
(2) Wind. Hybrids tend to be tuned to a given range of speeds more than "normal" ICE powered cars. My hybrids do fine up to 80 mph, above that you start to see efficiency loss. Heck, one time, I was driving into a 30+ mph wind, doing just 65 mph in an Accord iMMD. That means the car was driving through the air at about 95 mph (*). On that particular stretch of the commute the mileage dropped to 28 mpg.
Now, you'd think that hills and mountains would affect mileage.. and in a way they do. But in reality, what goes up, comes down. And hybrids tend to be pretty good at regen and coasting. You might go up a mountain pass (Shiskiyou) doing 23 mpg with an empty battery and the ICE all rev'ved up. But on the way down, you'll see 100 mpg, a full battery and the only drawback is that you're on the real brakes as regen is done its job.
I ought to note that our Clarity FCEV behaves pretty much the same as if it were an iMMD without the high speed direct drive (BEV, not quite PHEV).
(*) This was the day four years -or so- ago when the big fires started in North San Diego Cty.
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JeffX
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TonyEX wrote:
I've driven my hybrids (06 IMA, '14/'5 iMMDs) in 110F/30F weather with no loss of efficiency.
If you're interested in what really kills efficiency: aerodynamics and rain.
(1) Rain. The wet pavement increases the rolling resistance of your tires. I've seen as much as a 10% decrease in efficiency.
(2) Wind. Hybrids tend to be tuned to a given range of speeds more than "normal" ICE powered cars. My hybrids do fine up to 80 mph, above that you start to see efficiency loss. Heck, one time, I was driving into a 30+ mph wind, doing just 65 mph in an Accord iMMD. That means the car was driving through the air at about 95 mph (*). On that particular stretch of the commute the mileage dropped to 28 mpg.
Now, you'd think that hills and mountains would affect mileage.. and in a way they do. But in reality, what goes up, comes down. And hybrids tend to be pretty good at regen and coasting. You might go up a mountain pass (Shiskiyou) doing 23 mpg with an empty battery and the ICE all rev'ved up. But on the way down, you'll see 100 mpg, a full battery and the only drawback is that you're on the real brakes as regen is done its job.
I ought to note that our Clarity FCEV behaves pretty much the same as if it were an iMMD without the high speed direct drive (BEV, not quite PHEV).
(*) This was the day four years -or so- ago when the big fires started in North San Diego Cty.
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I've noticed SUBSTANTIAL dips in fuel economy even at 40F in Honda hybrids, particularly on shorter (in town) drives. And I agree about the speed range sensitivity. Accord Hybrid will do 45+MPG at speeds up to around 70mph but as soon as you cross that 70mph threshold you're lucky to maintain 40mpg. At 80mph you might be barely better than an Accord V6.
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CarPhreakD
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JeffX wrote:
KyDave95 wrote:
CarPhreakD wrote:
Not sure about all hybrids, but in BEVs most vehicles have either a coolant or AC based thermal management system. I think most hybrids are less concerned because they use more robust battery chemistries (ye' old NiMH) and those batteries aren't typically stressed as heavily via charging or discharging.
As far as in a static scenario where you're mostly concerned about heat conduction from the road or ambient temps, there are also limits- but unless you live in like, Arizona or Alaska, you won't likely hit them. For example, the ubiquitous (for Tesla) Panasonic Lithium Ion battery has a pretty wide latitude for storage temps. On this same datasheet you can see discharge characteristics, and specifically how detrimental cold temperatures are to battery function.
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Ooh, an actual data sheet...thanks! I'll take a closer look at it when I get back to the house...
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-20C to 50C
that's -4F to 122F.
I've approached or surpassed both extremes this calendar year.
Car interiors routinely soar above 60C in the summer here in the south - not sure how much of that radiates to the batteries after hours of sitting outside. And we were in West Virginia (and Kentucky) earlier this year and it was -11F overnight while we were there. The datasheet doesn't say what happens to those cells when the storage temp ranges are exceeded but it's not difficult to find places in the US where you'll test those limits.
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It is slightly better if you're talking hybrid batteries where they are within the back seat area. But the ones in BEVs that are under the car are subject to road heat.
Nothing really happens to those cells for the most part, unless you spend extended amounts of time in that kind of weather. The most actually damaging usage of batteries is full current load at low temperatures. I think most hybrids avoid really stressing their batteries because they can just lean on their ICEs until batteries are within the correct temp threshold- though as you alluded to, it can drastically affect fuel economy.
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KyDave95
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Nick GravesX wrote:
A/C consists of a pretty constant load, probably equivalent of about 5 BHP.
In terms of the ~100 BHP you may be demanding/not demanding. it's not really significant.
The problem with miserable winters is you're running lights, wipers, A/C or Heat pump, seat heaters etc plus frictional losses from standing water/pissing rain. Then it may add up to be significant if you are getting low on charge.
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Yeah, I never really thought about it before now, but I've had all of that stuff going on, plus the radio on as well! Thank you!
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KyDave95
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CarPhreakD wrote:
JeffX wrote:
KyDave95 wrote:
CarPhreakD wrote:
Not sure about all hybrids, but in BEVs most vehicles have either a coolant or AC based thermal management system. I think most hybrids are less concerned because they use more robust battery chemistries (ye' old NiMH) and those batteries aren't typically stressed as heavily via charging or discharging.
As far as in a static scenario where you're mostly concerned about heat conduction from the road or ambient temps, there are also limits- but unless you live in like, Arizona or Alaska, you won't likely hit them. For example, the ubiquitous (for Tesla) Panasonic Lithium Ion battery has a pretty wide latitude for storage temps. On this same datasheet you can see discharge characteristics, and specifically how detrimental cold temperatures are to battery function.
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Ooh, an actual data sheet...thanks! I'll take a closer look at it when I get back to the house...
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-20C to 50C
that's -4F to 122F.
I've approached or surpassed both extremes this calendar year.
Car interiors routinely soar above 60C in the summer here in the south - not sure how much of that radiates to the batteries after hours of sitting outside. And we were in West Virginia (and Kentucky) earlier this year and it was -11F overnight while we were there. The datasheet doesn't say what happens to those cells when the storage temp ranges are exceeded but it's not difficult to find places in the US where you'll test those limits.
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It is slightly better if you're talking hybrid batteries where they are within the back seat area. But the ones in BEVs that are under the car are subject to road heat.
Nothing really happens to those cells for the most part, unless you spend extended amounts of time in that kind of weather. The most actually damaging usage of batteries is full current load at low temperatures. I think most hybrids avoid really stressing their batteries because they can just lean on their ICEs until batteries are within the correct temp threshold- though as you alluded to, it can drastically affect fuel economy.
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This is exactly the type of discussion I was hoping for. Other than the impact of temperature extremes on fuel economy, I wasn't able to locate much useful information before, so all of the responses here are really helpful. Thanks everyone!
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