Battery Charging and Storage Options in the Heat!

[leehop71]

I skimmed over the threads and didn’t see anything alluding to this, but if I missed something, accept my apologies!

I just left my bike shop where I bought a basket. During our discussions this is what the tech advised.

First off, we both agreed that the charger should be left in the house in between charges in the heat!

He also said that charging the battery should ALWAYS be done outside of the living quarters, preferably inside the garage. Reason being, in the unlikely event of a fire, you don’t want it to occur inside your home!

But he also said he leaves his battery ON his bike all the time because, on the knock off brands some may have cut corners and you never know what a person may be inhaling coming from the battery, IF you store it inside your home in between rides.

Thoughts? Opinions?

 

[Jeremy McCreary]

Also interested in this topic — especially regarding how hot a garage is too hot for safe ebike battery storage. I mean scientifically too hot.

Yesterday, our garage got up to 88°F at the end of our warmest day yet this year. (I can hear our recent heat-dome victims laughing.) Guessing that's safe fire-wise and not too hard on battery longevity, but would like to know for sure.

Just to be clear, the alternative to garage storage is also dangerous: Any attempt to store bike stuff inside our small house would immediately result in the bike and I both being out on the street.

First off, we both agreed that the charger should be left in the house in between charges in the heat!

Why store the charger in the house? Is it any more heat-sensitive than the tool battery charger or car electronics that live in your garage?

 

[leehop71]

Also interested in this topic — especially regarding how hot a garage is too hot for safe ebike battery storage. I mean scientifically too hot.

Yesterday, our garage got up to 88°F at the end of our warmest day yet this year. (I can hear our recent heat-dome victims are laughing.) Guessing that's safe for us and not too hard on battery longevity, but would like to know for sure.

Just to be clear, the alternative to garage storage is also dangerous: Any attempt to store bike stuff inside our small house would immediately result in the bike and I both being out on the street.


Why store the charger in the house? Is it any more heat-sensitive than the tool battery charger or car electronics that live in your garage?

Just a precaution that is easy to do with no danger to anyone!

 

[leehop71]

Also interested in this topic — especially regarding how hot a garage is too hot for safe ebike battery storage. I mean scientifically too hot.

Yesterday, our garage got up to 88°F at the end of our warmest day yet this year. (I can hear our recent heat-dome victims laughing.) Guessing that's safe for us and not too hard on battery longevity, but would like to know for sure.

Just to be clear, the alternative to garage storage is also dangerous: Any attempt to store bike stuff inside our small house would immediately result in the bike and I both being out on the street.


Why store the charger in the house? Is it any more heat-sensitive than the tool battery charger or car electronics that live in your garage?

I guess my biggest concern is whether or not to keep battery on the bike or to n the house in between rides???

 

[leehop71]

My Emtbs came with an owner's manual. In it. Has instructions for correct way to charge battery. Did your ebike come with instructions?

Yes, but it doesn’t address this specific issue

 

[leehop71]

Yes chargers are for indoor use. You have to factor in ambient temperature.
I charge my batteries indoor in my living room with air conditioning immediately after riding. Battery inside the bike.
If you're scared of batteries exploding you bought the wrong ebike.
I live in tropical island, ambient temperature does not affect my charging habits.

My manual does say to wait at least 45 minutes AFTER the ride before charging.

So you bring your bike inside the house?

Do you keep your bike inside or in a garage?

 

[pmcdonald]

These random thoughts are going to come across elitist, so you've been forewarned. I think where and how you charge is going to come down to the quality (very often but not always correlated with cost) of a battery pack and its integrity.

I'd have no issue charging a brand name pack inside, and do with mine on and off the bikes. One of these packs clatters down rutted trails, off drops and rocks every chance I get. I would have an issue doing so with a more value-oriented battery. On occasion when I've borrowed friends cheaper bikes I've limited charging to undercover and outdoors.

This article has some surprisingly good tips: https://techcrunch.com/2023/07/11/everything-you-need-to-know-about-e-bike-battery-fires/amp/
It also makes the point that the startling rise in lithium fires correlates with the increase in delivery ebikes: cheap bikes that have a hard life. Once you discount these, dodgy DIY builds, bargain basement Amazon bikes and batteries with physical damage I do question how widespread ebike fires are.

But to me it just comes down to economics. A brand name battery is built from cells subject to QC culling ($$$) and certified to a higher standard (more $$$). And then the brands will throw a premium on top for good measure to cover any warranty issues the battery firmware picks up ($$$). It's also very much not in the long term interests of the big names to be burning down houses. Long term reputation may be less of a priority for someone dropshipping a container of generic ebikes.

If you do need to charge indoors, some users here do so in a gun ammo safe. Which is apparently a thing.

What sort of temperature ranges are we talking here? My bikes operate in about 5C - 45C, and get charged between 15C - 30C.

 

[leehop71]

These random thoughts are going to come across elitist, so you've been forewarned. I think where and how you charge is going to come down to the quality (very often but not always correlated with cost) of a battery pack and its integrity.

I'd have no issue charging a brand name pack inside, and do with mine on and off the bikes. One of these packs clatters down rutted trails, off drops and rocks every chance I get. I would have an issue doing so with a more value-oriented battery. On occasion when I've borrowed friends cheaper bikes I've limited charging to undercover and outdoors.

This article has some surprisingly good tips: https://techcrunch.com/2023/07/11/everything-you-need-to-know-about-e-bike-battery-fires/amp/
It also makes the point that the startling rise in lithium fires correlates with the increase in delivery ebikes: cheap bikes that have a hard life. Once you discount these, dodgy DIY builds, bargain basement Amazon bikes and batteries with physical damage I do question how widespread ebike fires are.

But to me it just comes down to economics. A brand name battery is built from cells subject to QC culling ($$$) and certified to a higher standard (more $$$). And then the brands will throw a premium on top for good measure to cover any warranty issues the battery firmware picks up ($$$). It's also very much not in the long term interests of the big names to be burning down houses. Long term reputation may be less of a priority for someone dropshipping a container of generic ebikes.

If you do need to charge indoors, some users here do so in a gun ammo safe. Which is apparently a thing.

What sort of temperature ranges are we talking here? My bikes operate in about 5C - 45C, and get charged between 15C - 30C.

Thanks PM. My bike is a Denago and it’s SW Florida. From June - October often in the 90s with high humidity!

Not sure how hot it gets in the garage. I do need to get a temperature gauge and humidistat!

 

[harryS]

Specs on the lithium cells say storage temperatures are -20C (-5F) to 40C (122F). Mine are safe in the garage,, I keep some small lithium batteries outside in an bbq grill where we flirt with -5F in January, One year, I had to move them into the garage.

You can ride your ebikes down to 0 F, but you can't recharge unless the insides of the battery are above 40-45F.

 

[leehop71]

I was very meticulous from the get go I bought one of these tools for checking temperature.
At first I was pointing it on the motor obviously it is hot after 20 mile jaunt.
Point it at the battery and refer to your manual for proper charging temperature.

The good thing about my situation in this heat I ride about a 6 mile 25 minute round trip every morning before 9am, in this heat, M-F so it’s not a

Specs on the lithium cells say storage temperatures are -20C (-5F) to 40C (122F). Mine are safe in the garage,, I keep some small lithium batteries outside in an bbq grill where we flirt with -5F in January, One year, I had to move them into the garage.

You can ride your ebikes down to 0 F, but you can't recharge unless the insides of the battery are above 40-45F.

So I guess it’s safe to keep my battery in the garage and charge it on the bike IN the garage!

I just bought a temperature/humidistat wall mount for the garage!!

 

[m@Robertson]

But he also said he leaves his battery ON his bike all the time because, on the knock off brands some may have cut corners and you never know what a person may be inhaling coming from the battery, IF you store it inside your home in between rides.

Batteries many decades ago could emit gasses when they got wet, but I am thinking of batteries on a U-boat during WWII. In 2024 this is I think a ridiculous concern. Ask for a source confirming this danger is in any way real. I leave my batteries on my bikes all the time too but I bring the bikes indoors when the heat comes.

Just a precaution that is easy to do with no danger to anyone!

Yeah but also no benefit to anyone. You could move your electric drill inside the house from the garage as a precaution but that is perhaps more clearly a pointless exercise. This is assigning the charger guilt by association with batteries but its nothing more than a low-voltage power source.

So I guess it’s safe to keep my battery in the garage and charge it on the bike IN the garage!

Safe from thermal runaway is not the same thing as safe from degradation. Heat is the enemy of li ion cells. This article below comes from 2017 so its not exactly new news. It gets into some pretty obscure technical lingo, but you can skim-read it. The subhead sections like

Temperature…HOT is BAD

tell a tale all by themselves. The Conclusion section is worth a close read.

How to make a lithium battery last, or…kill it, if you like.

We have written in the past about tips that will help your expensive lithium battery pack last as long as possible. This article will cover some additional information about what happens inside the…

www.electricbike.com

 

[leehop71]

Batteries many decades ago could emit gasses when they got wet, but I am thinking of batteries on a U-boat during WWII. In 2024 this is I think a ridiculous concern. Ask for a source confirming this danger is in any way real. I leave my batteries on my bikes all the time too but I bring the bikes indoors when the heat comes.

Yeah but also no benefit to anyone. You could move your electric drill inside the house from the garage as a precaution but that is perhaps more clearly a pointless exercise. This is assigning the charger guilt by association with batteries but its nothing more than a low-voltage power source.


Safe from thermal runaway is not the same thing as safe from degradation. Heat is the enemy of li ion cells. This article below comes from 2017 so its not exactly new news. It gets into some pretty obscure technical lingo, but you can skim-read it. The subhead sections like

Temperature…HOT is BAD

tell a tale all by themselves. The Conclusion section is worth a close read.

How to make a lithium battery last, or…kill it, if you like.

We have written in the past about tips that will help your expensive lithium battery pack last as long as possible. This article will cover some additional information about what happens inside the…

www.electricbike.com

I like your advice and expertise. I read the nuts and bolts of the article and it seems to me that this procedure would be the best solution for me.

Since getting gasses emitted is NOT an issue, it sounds like my best option would be, from June through October here in Florida, is to keep the battery inside, in between rides, charging it inside as well!?

My sons bedroom is empty so I keep the charger there and could remove battery AFTER the ride, store it in the room until the next ride, charge as needed inside.

Praying that because I ride in the early mornings and only 5 miles M-F, fire issues while charging inside should NOT be an issue?!?

 

[sc00ter]

Oh boy, my situation:
Inside my garage it'll get to 110F! And with our recent heatwaves this has been ongoing for a few days now. I use a box fan and aim it across the enclosed battery of the Lectric XP. This horrible storage method is used because of the difficulty in easily removing the battery from the frame. I also charge it during the night, when its cooler. And yes, I've forgotten about it and it sat overnight several times on the charger. The charger does stay off the floor as the floor will sweat during certain weather conditions. So far so ....?

And think of this, IF the battery was to burst into flames and I have a box fan blowing across it, mega fire! But I don't worry about the battery bursting into flames. I'm either gullible or lucky but I feel Lectric uses good enough batteries.

On all my other ebikes I always pulled the battery and bring it inside. When I pull the trigger on a Xpedition I'll pull the batteries when it's in the garage/oven and bring them inside. I'm just waiting on a good bundle package to be included to inspire me.

 

[J.R.]

I like your advice and expertise. I read the nuts and bolts of the article and it seems to me that this procedure would be the best solution for me.

Since getting gasses emitted is NOT an issue, it sounds like my best option would be, from June through October here in Florida, is to keep the battery inside, in between rides, charging it inside as well!?

My sons bedroom is empty so I keep the charger there and could remove battery AFTER the ride, store it in the room until the next ride, charge as needed inside.

Praying that because I ride in the early mornings and only 5 miles M-F, fire issues while charging inside should NOT be an issue?!?

Sounds reasonable. I've owned ebikes and many packs for 9 years and my practices have been refined in that time. When I started, I commuted 34 miles a day and I would charge overnight in the house. Because I ride in 90+ to well below freezing temperatures I always let the battery rest an hour before charging. Now I charge in the all concrete utility room in the basement and store them in a basement woodstove. I could charge in the stove, but I keep an eye on them and take them off the charger when they are fully charged. I never charge overnight. I still let them rest before charging.

If you can charge and store them on a fireproof surface away from anything combustible.

 

[teskow]

Everybody has an opinion regarding the handling of ebike batteries. Generally lithium. It is not hard to find good reliable info on the proper use and care of lion batteries, be they in our bike, car or hand tools. Advice that is written by the manufacturer or battery engineers. Some like to think they know better than the engineers who designed and tested the product. Personally I like to follow their advice. I live in the desert and it regularly gets to 110+F in my garage on a daily basis in the summer. Common sense tells me to bring anything sensitive to excessive heat into a conditioned storage area when it is that hot. For my situation it is easy to wheel my entire bike into the house when it gets over 85 degrees in my garage. If it was hard to bring the entire bike in the house I would certainly bring the battery into a conditioned area. We all know excessive heat, charging Lion batteries immediately after just riding is not recommended. I am on my third ebike and that info came with each bike.

 

[scottsdalecommuter]

The only change I’ve made is I put my charger on a metal wire basket to get some air flow under it because it was making the counter hot to the touch which made me nervous.

 

[Jeremy McCreary]

Everybody has an opinion regarding the handling of ebike batteries. Generally lithium. It is not hard to find good reliable info on the proper use and care of lion batteries, be they in our bike, car or hand tools. Advice that is written by the manufacturer or battery engineers. Some like to think they know better than the engineers who designed and tested the product. Personally I like to follow their advice. I live in the desert and it regularly gets to 110+F in my garage on a daily basis in the summer. Common sense tells me to bring anything sensitive to excessive heat into a conditioned storage area when it is that hot. For my situation it is easy to wheel my entire bike into the house when it gets over 85 degrees in my garage. If it was hard to bring the entire bike in the house I would certainly bring the battery into a conditioned area. We all know excessive heat, charging Lion batteries immediately after just riding is not recommended. I am on my third ebike and that info came with each bike.

Totally agree, practical recommendations should come straight from the technical experts. No room for online rumors with battery safety. Also no room for measures with no basis in engineering fact.

Where did you get your 85° trigger for bringing your battery inside?

 

[teskow]

Yep, that is a good question.
I have no idea. It is my unqualified non engineer feeling I pulled out of thin air.. Actually if I think it isn't going to get over 85 I do leave it in the garage.
I just love mechanical stuff and like to baby my machinery.

 

[leehop71]

Yep, that is a good question.
I have no idea. It is my unqualified non engineer feeling I pulled out of thin air.. Actually if I think it isn't going to get over 85 I do leave it in the garage.
I just love mechanical stuff and like to baby my machinery.

For me, I try to live by 2 philosophies:

1. I’d rather have something, and not need it, as opposed to needing something and not having it!

2. I’d rather err on the side of caution!

 

[leehop71]

My only concern is the fire issue while charging!

I’m getting a laptop cooler to sit my battery and charger on while charging indoors, just to err on the side of caution!