Battery Charging and Storage Options in the Heat!

[6zfshdb]

My English is not too good, reason why I post pictures of what I'm talking about.
I did not immediately plug it in because I had to bathe myself sweaty ass everything.

Thanks for not posting pics of that!

 

[6zfshdb]

I wonder how EV's handle battery thermal management in places like Houston or Anchorage. Yes, they have built in heating & cooling devices that operate while charging but what happens when they are stored in extreme temps when not connected to a charger?

 

[teskow]

I expect it shortens the lifespan of the battery from what I have read. Living in the blazing heat of the desert (Southern, AZ)is the reason I don't own an electric automobile. My kids live in Minneapolis MN and I, because of the extreme temps have advised them against an electric car. Will they listen to an old geezer, probably not. The extreme cold saps the battery of its full capacity and also the cabin heating takes a brutal amount of power. I have read that if you have your vehicle plugged in it is advisable to preheat the cabin so as to save the battery from having to do it.

 

[m@Robertson]

but what happens when they are stored in extreme temps when not connected to a charger?

Bad things, if the temperature gets too high. But it takes a lot to make that happen. Thermal runaway is generally considered to be a serious risk at about 140 degrees fahrenheit. That means you're safe from spontaneous combustion pretty much everywhere except somewhere like a steel shed in the sunlight, or a hot car in the summer sun, or maybe a hot garage when its 110 outside. It definitely gets above 130 in the summer in my closed up Fresno garage.

There isn't much in the way of thermal management involved when the battery is living in a hot environment and it is just flat out going to match ambient temperature. Check this pic out:

That is me parked at Costco in Clovis CA in the summer (my insurance kicks in if the bike is locked to a secure object, so I take pictures at every stop). The bike has been parked in the sun, right next to a steel wall, for about a half hour. The wall is radiating heat, and so is the sun down on the bike, but the battery is under the floor. So the real risk is the heat radiating up from the concrete. I keep a temperature sensor at the top of the pack inside that sub-floor box and when its parked in the sun I can see temps in the box of up to 105 after I come back out after my shopping trip. On the way home, I do my best on the bike path to roll over shaded areas and this is good for about a 5-degree temperature reduction inside the battery box. Look closely and you can see some heat sinks just behind the front wheel that are on three sides of the box and are good for about 3 degrees temp reduction while moving thru even hot air.

Since I have a temp sensor I use in real time, and I *know* how hot that pack gets, I don't shop mid-day. I will commute in 110-degree heat, but I won't park a bike outside in it.

The more practical question is how hot does it have to be to hurt the battery's longevity? I've heard the number to be 'over 100 degrees fahrenheit' but I don't generally want to push it that far - if I can help it. @teskow 's 85-degree limit is a good one if you want to ensure your battery investment doesn't die younger than it has to.

 

[J.R.]

Bad things, if the temperature gets too high. But it takes a lot to make that happen. Thermal runaway is generally considered to be a serious risk at about 140 degrees fahrenheit. That means you're safe from spontaneous combustion pretty much everywhere except somewhere like a steel shed in the sunlight, or a hot car in the summer sun, or maybe a hot garage when its 110 outside. It definitely gets above 130 in the summer in my closed up Fresno garage.

There isn't much in the way of thermal management involved when the battery is living in a hot environment and it is just flat out going to match ambient temperature. Check this pic out:
View attachment 161536

That is me parked at Costco in Clovis CA in the summer (my insurance kicks in if the bike is locked to a secure object, so I take pictures at every stop). The bike has been parked in the sun, right next to a steel wall, for about a half hour. The wall is radiating heat, and so is the sun down on the bike, but the battery is under the floor. So the real risk is the heat radiating up from the concrete. I keep a temperature sensor at the top of the pack inside that sub-floor box and when its parked in the sun I can see temps in the box of up to 105 after I come back out after my shopping trip. On the way home, I do my best on the bike path to roll over shaded areas and this is good for about a 5-degree temperature reduction inside the battery box. Look closely and you can see some heat sinks just behind the front wheel that are on three sides of the box and are good for about 3 degrees temp reduction while moving thru even hot air.

Since I have a temp sensor I use in real time, and I *know* how hot that pack gets, I don't shop mid-day. I will commute in 110-degree heat, but I won't park a bike outside in it.

The more practical question is how hot does it have to be to hurt the battery's longevity? I've heard the number to be 'over 100 degrees fahrenheit' but I don't generally want to push it that far - if I can help it. @teskow 's 85-degree limit is a good one if you want to ensure your battery investment doesn't die younger than it has to.

That is an awesome bike. If I lived in a town where most needs were met within a 15-mile radius, I'd give that a go. Even when I was a daily commuter of 34 miles, I still couldn't get to everything I needed. Worse now because the only grocery store within reach, closed down a few years ago. How much does all that security weigh?

 

[Jeremy McCreary]

Bad things, if the temperature gets too high. But it takes a lot to make that happen. Thermal runaway is generally considered to be a serious risk at about 140 degrees fahrenheit. That means you're safe from spontaneous combustion pretty much everywhere except somewhere like a steel shed in the sunlight, or a hot car in the summer sun, or maybe a hot garage when its 110 outside. It definitely gets above 130 in the summer in my closed up Fresno garage.

There isn't much in the way of thermal management involved when the battery is living in a hot environment and it is just flat out going to match ambient temperature. Check this pic out:
View attachment 161536

That is me parked at Costco in Clovis CA in the summer (my insurance kicks in if the bike is locked to a secure object, so I take pictures at every stop). The bike has been parked in the sun, right next to a steel wall, for about a half hour. The wall is radiating heat, and so is the sun down on the bike, but the battery is under the floor. So the real risk is the heat radiating up from the concrete. I keep a temperature sensor at the top of the pack inside that sub-floor box and when its parked in the sun I can see temps in the box of up to 105 after I come back out after my shopping trip. On the way home, I do my best on the bike path to roll over shaded areas and this is good for about a 5-degree temperature reduction inside the battery box. Look closely and you can see some heat sinks just behind the front wheel that are on three sides of the box and are good for about 3 degrees temp reduction while moving thru even hot air.

Since I have a temp sensor I use in real time, and I *know* how hot that pack gets, I don't shop mid-day. I will commute in 110-degree heat, but I won't park a bike outside in it.

The more practical question is how hot does it have to be to hurt the battery's longevity? I've heard the number to be 'over 100 degrees fahrenheit' but I don't generally want to push it that far - if I can help it. @teskow 's 85-degree limit is a good one if you want to ensure your battery investment doesn't die younger than it has to.

Here in coastal San Diego County, max garage temps of 85-90°F are probably pretty realistic most of the time. Battery-unfriendly low temps ain't gonna happen.

To catch the outliers, just ordered the following Bluetooth thermometer for the garage. The app sends a phone notification when the temp goes outside the user-defined range. Runs on (rechargeable) AAAs.

https://www.amazon.com/gp/aw/d/B07Y36FWTT/ref=ox_sc_saved_image_1?smid=A2KZ7X05DCDJDL&psc=1

Will report back.

Update: Returned bluetooth thermometer above (link now disabled). Unit arrived with a bad temp sensor. The app is clumsy and demands more personal data than it needs to do the job desired.

Will keep looking.

 

[m@Robertson]

How much does all that security weigh?

Somewhere in the ballpark of 15 lbs I think.

• Pragmasis 11mm noose chain, 2-meters (noosed to frame and rear wheel, run forward)
• Xena XSU-310 18mm stainless motorcycle lock (locks chain to bike rack thru front wheel)
• Pragmasis/Lockitt DIB-260 16mm U lock (independent lock around frame and rear wheel)

It should be easier to steal one of the cars nearby.

 

[leehop71]

1. In the General eBike Community - starting in FL - it started up as "don't leave or charge your battery outside when it's over "80"/"85" ( I have heard both #'s.

2. Li-On side the tech spec is Charging and Discharging at Temp is "OK" - but reduces the longevity of the battery before it drops off to 80% capacity,
Same as Charging Immediately after a ride when the cells are "hot" is "OK" = but the Chaarging Energy/Heat on top of Cell Heat from discharge again will reduce longevity making dropoff to 80% in fewer charge cycles.
Please note a IR Thermometer will pickup Case Temperarature - for our puposes here its "cell temperature" that is the Key Factor - and going forward more eBike batteries and controllers will have Temperature Communication.

3. I have attached "General eBike Battery Guidelines " that I have been playing around. off and on that started as well worded and with clear language from the Canadians. Overall it started striaght forward - no Techie Charts and Graphs. In general my experience falls in line with most of the doc.
However there is technical disagreement - are outside temperatures "too hot" at 85F or "too hot" at 115F 115F>
The other thing for me is a "my technical disagreement "- I have seen (many times) a Memory Effect in some eBike batteries - where the maximum capacity backs down to about 75% - in those cases it happens well before the necessary # of charging cycles to drop to 80%. I HATE eBike Li-On chargers as being Cheap and Stupid - the BMS and Controllers in Performance eScooters today are easily another level over eBike today.. I LOVE may Grin Satiator's as "Smart Chargers" - best $350 investment I have made for my eBike/eScooter "Mini-Fleet" with thr Satiator since you can set charging profiles and set max charge capacity. I "don't know" who designed it - and I haven't seen anything else like it in China for Li-On.

Check the attached doc - I am NOT presenting this as a "Edict" - I am presenting it as a work-in-process with "Clear Language and Clear Sensibilities"

I’m going with the philosophy of erring on the side of caution!

I bring my battery inside after the ride and store in a fireproof bag in an empty bedroom until the next ride!

When it NEEDS to be charged, I bring it in AFTER the ride, put it in the fireproof bag for a minimum of 2 hours.

As per manual, I plug into the battery first, then into the outlet, set my charger on a laptop cooler, zip the bag closed with just the wire sticking out!

 

[m@Robertson]

I HATE eBike Li-On chargers as being Cheap and Stupid
I LOVE may Grin Satiator's as "Smart Chargers"
I haven't seen anything else like it in China for Li-On.

The Grin Satiator is to all intents and purposes an LED power supply with a display screen and a menu interface built in. Having no fan (to fail) it is designed to live with the heat it generates via radiating same out of the casing, which is a good thing.

The bad part comes with the $350 price tag. You can, instead, buy an actual LED power supply, that has adjustable potentiometers for voltage and current (amps). They are designed for commercial signs and municipal street lights, and come with Mean Time Between Failure ratings in the range of 200,000 hours. For reals. These things are designed to last for decades. Also they are truly weatherproof/IP65 and can be mounted externally on a bicycle if you want to do that. Cost once you kit one out is about 1/3 of a Satiator, and the only thing you lose is the computerized interface. Instead, you twiddle a 'dial' for your current and voltage level.

An Ultra Reliable Ebike Battery Charger…

How about a charger – quickly adjustable for voltage and current – that is rated for hundreds of thousands of hours of use before it typically fails?

talesontwowheels.com

 

[Gionnirocket]

DIY Smart Charger... Charge to any voltage with a 0.1v resolution using any charger and also has a timed shutdown for additional safety... All for less than $25
Take that Satiator.

 

[GizmoEV]

I wonder how EV's handle battery thermal management in places like Houston or Anchorage. Yes, they have built in heating & cooling devices that operate while charging but what happens when they are stored in extreme temps when not connected to a charger?

The good ones heat or cool while not charging, too. I know my 2023 Kia Niro EV will heat the battery in the winter while on a trip so that it is at a good charging temperature when I arrive at a charge station as long as it has been entered into the navigation system. It will also heat the battery if needed to maintain performance.

 

[6zfshdb]

The good ones heat or cool while not charging, too. I know my 2023 Kia Niro EV will heat the battery in the winter while on a trip so that it is at a good charging temperature when I arrive at a charge station as long as it has been entered into the navigation system. It will also heat the battery if needed to maintain performance.

There is no climate issue while the vehicle is in operation but what about when it is parked outdoors for an extended period of time, like in an airport parking lot?

Temperature control systems in EV's can't run forever when the vehicle isn't in use or on a charger. Eventually, the battery would discharge completely.

 

[Gionnirocket]

There is no climate issue while the vehicle is in operation but what about when it is parked outdoors for an extended period of time, like in an airport parking lot?

Temperature control systems in EV's can't run forever when the vehicle isn't in use or on a charger. Eventually, the battery would discharge completely.

I wonder if solar is up to the task.
Long term parking will have to include a little more than a trickle charger

 

[GizmoEV]

Temperature control systems in EV's can't run forever when the vehicle isn't in use or on a charger. Eventually, the battery would discharge completely.

Right, mine will go into a hibernate mode if left for a few days. Even a cold battery will put out some energy which can be used to heat it when the vehicle is turned on. In very cold climates should be plugged in the same way ICE vehicles block heaters are plugged in.

Cold batteries don't really lose capacity, it is that their power delivery goes down so the electronics thinks the battery goes dead sooner due to the greater voltage sag.