Storing battery outside in winter - what insulation?

[peterjd]

TG85 Dusk to Dawn Timeswitch. If you have one of these lying around (our electricity supplier gave them away a few years ago), they make good charger timers if you stick a piece of opaque tape over the centre light sensor. I used one extensively in the summer to charge my battery overnight in hotels etc., during a tour.

 

[Wayners]

I'm going to put a sonoff WiFi switch on my charger cable. Cost £6.
I can control from phone either timed or manuel.
Currently using a plugin timer. I just turn leaving a set time remaining. Takes 6 hours to charge my battery so most nights I turn timer allowing for 2 hours charging. I never look at the time markings on timer. Fiddly and difficult to set so I don't bother.

I'll post how it works out..


Oh.

This one. Although you can buy plugs vs cutting wire and adding switch.

 

[Saracen]

These are not safe storage ways. Both items might protect your house from fire if lucky enough, but you won't be protected from toxic smoke.

Edit:

https://www.amazon.co.uk/gp/product/B09C31KVK1/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

On second picture you see two people asleep while battery is on charge next to their bed. In worst case scenario if anything happens it is instant death.

On a video you can see a guy wearing a hat in his house talking about bag. There is a baby making noises, half of a dog in the background and a monitor with cables on a landing. I don't know this product to be honest, but marketing is completely lame and does not inspire confidence. Good luck to anybody who would like to bet their life on it.

NOTHING is 100% safe hence so many gun killings in the US, what we do is to try to mitigate against trouble as much as possible

 

[thelarkbox]

I'm going to put a sonoff WiFi switch on my charger cable. Cost £6.
I can control from phone either timed or manuel.
Currently using a plugin timer. I just turn leaving a set time remaining. Takes 6 hours to charge my battery so most nights I turn timer allowing for 2 hours charging. I never look at the time markings on timer. Fiddly and difficult to set so I don't bother.

I'll post how it works out..


Oh.

This one. Although you can buy plugs vs cutting wire and adding switch.

Reflash the sonoff with tasmota, dont rely on remote servers to control your local gear. would be a pita if your internet went down and you lost control of the off switch.. Theo's project has All the bases covered, With Zero reliance on any external servers.
If a newbie to programming etc dont worry there is a helpful installer.. and the docs above are comprehensive and actively supported
If you get stuck there is a Very friendly help group hosted on googlegroups 'Sonoffusers' recently renamed 'TasmotaUsers' you only need a google id to access.. (everyone started as a know nothing newbie..)

sonoff/tasmota fanboy here u pressed my button..

 

[AntonyC]

"Takes 6 hours to charge my battery so most nights I turn timer allowing for 2 hours charging."
That's most of the battle, and begin a few hours before bed because a hot cell can take a long time to go fully rogue.

 

[AntonyC]

Reflash the sonoff with tasmota

Can you get these with an integral time-out and easy indication of whether that's set? I wouldn't want to go out forgetting my phone was set to send an OFF.

 

[Az.]

NOTHING is 100% safe hence so many gun killings in the US, what we do is to try to mitigate against trouble as much as possible

I would argue the way I charge and store batteries is 100% safe while your way is very unsafe.

 

[AntonyC]

2. I also use this because it has BOTH a ZIP that closes in the MIDDLE and velcro OVER the zip

A lipo fire expels hot gas. In the smallest of fires both the zip and the velcro would be toast.

Edit: How do we get an Amazon listing taken down?

 

[thelarkbox]

Can you get these with an integral time-out and easy indication of whether that's set? I wouldn't want to go out forgetting my phone was set to send an OFF.

ER yes ? pm sent.. if i understand correctly even the sonoffbasic has a spare gpio exposed so adding a led/rgb for a visual indicator is doable with basic soldering skils (use pcb solderpads)

 

[flecc]

Operating a Li-ion pack below 0 C is ok, but expect a significant drop in capacity. However, charging should be done above 0 C or you may have issues. So use enough heating to keep the outside shed above freezing, but it doesn't have to be much above freezing.

I disagree with the above I've highlighted in bold, the electric car world is far more experienced with large lithium ion batteries and nowhere more so than Norway. That country sits across the arctic circle and for years well over half of all new car registrations has been for electric cars, very many of them for the Nissan Leaf. For that market Nissan fit a battery heater, here's Nissan's details on that:

"The Li-ion battery warmer automatically turns on when the Li-ion battery temperature is approximately -17 °C (-1 °F) or colder. The Li-ion battery warmer automatically turns off when the Li-ion battery temperature is approximately -10 °C (14 °F) or higher."

Note, heating is used only at 10 degrees C or more below freezing. It's similar for other e-car makes, clearly charging at well below freezing doesn't damage the batteries which are now known to last up to 12 years or possibly more.
.

 

[thelarkbox]

If your focus is getting the best performance from your battery perhaps keeping the battery in warmer temps for overnights and charging has appeal. providing the ability to eek out a few more amps and miles.

If however your battery has ample capacity for your regular needs there is no need to take the extra care of the battery perhaps?

 

[lenny]

lucky

'It took the fire brigades five minutes and the house had gone': How a family lost everything after e-bike battery exploded

Andrew Beaton describes the harrowing moment the e-bike's battery of his son 'exploded like grenade' while charging and destroyed their family home. It's the latest case of a house fire linked to an e-bike or e-scooter battery, and the government is facing calls for more regulation.

news.sky.com

 

[WheezyRider]

I disagree with the above I've highlighted in bold, the electric car world is far more experienced with large lithium ion batteries and nowhere more so than Norway. That country sits across the arctic circle and for years well over half of all new car registrations has been for electric cars, very many of them for the Nissan Leaf. For that market Nissan fit a battery heater, here's Nissan's details on that:

"The Li-ion battery warmer automatically turns on when the Li-ion battery temperature is approximately -17 °C (-1 °F) or colder. The Li-ion battery warmer automatically turns off when the Li-ion battery temperature is approximately -10 °C (14 °F) or higher."

Note, heating is used only at 10 degrees C or more below freezing. It's similar for other e-car makes, clearly charging at well below freezing doesn't damage the batteries which are now known to last up to 12 years or possibly more.
.

The question is whether you are talking about charging or discharging. Discharging, no problem to quite a way below zero (but you will lose capacity). Charging is a different issue. Charging below zero you risk doing damage. I posted some papers on this in a thread last winter.

It's not really appropriate to compare car battery systems with e-bike systems. Cars have much more sophisticated control systems and with inbuilt heating and cooling in most cases.

 

[flecc]

The question is whether you are talking about charging or discharging. Discharging, no problem to quite a way below zero (but you will lose capacity). Charging is a different issue. Charging below zero you risk doing damage. I posted some papers on this in a thread last winter.

It's not really appropriate to compare car battery systems with e-bike systems. Cars have much more sophisticated control systems and with inbuilt heating and cooling in most cases.

I was speaking of charging of course, which does not cause damage below zero degrees until much lower temperatures are reached, as I showed.

And what you say about car systems is not true in this respect as I mentioned again with car batteries that either don't have heating and cooling systems or limit their action to below very low temperatures. The current 40 kWh Nissan Leaf for example has the battery heating I described for Norway since in their arctic region conditions can get very extreme, but not for the UK, so mine doesn't have it. Nor for the Shetland Islands which share the 60th parallal with Norway, yet where they are keen on e-cars and are proud of their new tidal power charging point on the island of Yell.

The sophistication e-car chargers do have is that the rapid and ultra-rapid chargers reduce the charge rate at very low battery temperatures. But with our pedelec 2 amp chargers we dont need to be concerned about that since they are slow chargers anyway. And our lithium-ion batteries use the same cells as many e-cars, 18650s and 21700s.
.

 

[soundwave]

my bosch charger is 4a but says i can use 6a if i want.

 

[guerney]

my bosch charger is 4a but says i can use 6a if i want.

Charge at 20A and you'll need The Flaming Ebike Battery Flinger:

https://www.pedelecs.co.uk/forum/threads/never-tackle-an-e-bike-battery-fire-yourself-warns-fire-brigade-after-another-blaze.46121/#post-692868

 

[guerney]

Store in a METAL container, what better

1. https://www.viking-direct.co.uk/en/pierre-henry-steel-filing-cabinet-with-2-lockable-drawers-maxi-400-x-400-x-660-mm-grey-p-2DR-GY?customerType=consumer&utm_source=google&utm_medium=organic&utm_campaign=surface_google&cm_mmc=Google-_--_--_-2DR-GY&gclsrc=aw.ds&gclid=Cj0KCQjw9rSoBhCiARIsAFOiplkL1vViX1TDKR1dC3dCChzfylWIw0P22eh4egX0uK5L-aOM8Ay3YdgaAs70EALw_wcB

Lithium ion battery fires can burn at 2,000 degrees Celsius. Steel melts at 1425-1540 °C, so that's useless.

2. I also use this because it has BOTH a ZIP that closes in the MIDDLE and velcro OVER the zip https://www.amazon.co.uk/gp/product/B09Q6FPGZ5/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

"temperature resistance up to 1800℉" = 982.2°C, therefore also useless.

I already have a Bat Safe fireproof box.

That website doesn't even state what material that product is made from. For all we know it could be made from molten robot bat droppings. My guess is stainless steel, if so, also useless with a ebike battery afire. Might be ok for small battery packs with a small number of cells IMHO.

There really should be an internationally approved safety standard for such products, and a Flaming Kite Mark (not the bird).

 

[WheezyRider]

I was speaking of charging of course, which does not cause damage below zero degrees until much lower temperatures are reached, as I showed.

And what you say about car systems is not true in this respect as I mentioned again with car batteries that either don't have heating and cooling systems or limit their action to below very low temperatures. The current 40 kWh Nissan Leaf for example has the battery heating I described for Norway since in their arctic region conditions can get very extreme, but not for the UK, so mine doesn't have it. Nor for the Shetland Islands which share the 60th parallal with Norway, yet where they are keen on e-cars and are proud of their new tidal power charging point on the island of Yell.

The sophistication e-car chargers do have is that the rapid and ultra-rapid chargers reduce the charge rate at very low battery temperatures. But with our pedelec 2 amp chargers we dont need to be concerned about that since they are slow chargers anyway. And our lithium-ion batteries use the same cells as many e-cars, 18650s and 21700s.
.

I haven't got a lot of time to comment on this now, but I'm not convinced by your arguments and I'm worried that people might read what you have written and blindly assume cold weather charging is fine for e-bike systems. An internet search on charging lithium batteries below freezing will tell you from a wide range of sources - it's generally a bad idea.

The problem is that when a Li ion battery freezes the speed at which lithium ions can diffuse through the electrolyte and intercalate within the electrode is significantly reduced and so ions tend to pile up and form metallic lithium on the outermost parts of the electrode. This is bad as it means a permanent loss of capacity, that lithium never gets released back during discharge. Also, the lithium can form dendrites that can end up piercing the separator between the electrodes causing a short and potentially a battery fire.

Some specialised prismatic cells have been designed for operation at lower temperatures, but they say if used below freezing to reduce charge rates to C1/20. I would not be happy to advise e-bike users with a blanket "yes it's fine to charge your bike below freezing with the supplied 2 A charger". People have all sorts of different pack sizes and chargers and different BMS controls etc. I think people have to be careful and see if it is appropriate for their particular situation. Take a 4p pack made of 2.5 Ah cells, C1/20 is a lot less than what a 2 A charger would supply.

The e-bike batteries I have bought have always advised against charging below freezing.

As a minor aside...Just because the Shetlands are on a similar latitude to cold places does not mean it gets so cold in winter:

Winter in Shetland - FAQs | Shetland.org

Alex Garrick Wright runs through some of our most frequently asked questions about life in Shetland during the winter, and explains that, far from it being cold, snowy and isloated, winter in Shetland is suprisingly mild - if a little breezy.

www.shetland.org

 

[Woosh]

I'm looking into installing an Asgard ebike metal shed outside my home for my ebike, and running power to it (it comes with built in plates for this).

I'm aware the advice is generally to store the battery inside, but I'm looking into if there's a good way to store it outside. I'd much prefer this from a fire safety point of view.

I already have a Bat Safe fireproof box. Even with this, I'd prefer to keep it outside. I'm in the UK, so it gets cold, occasionally sub zero but rarely.

Do you think with some additional insulation for the battery inside the the Bat Safe box (maybe a neoprene cover or something), it would be ok throughout the year? Cheers.

Batteries have a range of abilities.
You should let us know the capacity of your battery and which cells are installed inside and which model of charger you have.
We can then look up the cells manufacturers recommendations for you. Typically, you should avoid charging the battery in freezing conditions, 10 degrees centigrade is the minimum recommended charging ambient temperature. If it's freezing, take your battery indoors to warm it up before taking it back to your shed to charge. Once you start charging, the charging current should maintain the temperature reasonably warm the rest of the charging time. For storage and rides, your battery is typically usable down to minus 10, -15 or even -20 centigrade.

 

[flecc]

I haven't got a lot of time to comment on this now, but I'm not convinced by your arguments and I'm worried that people might read what you have written and blindly assume cold weather charging is fine for e-bike systems. An internet search on charging lithium batteries below freezing will tell you from a wide range of sources - it's generally a bad idea.

The problem is that when a Li ion battery freezes the speed at which lithium ions can diffuse through the electrolyte and intercalate within the electrode is significantly reduced and so ions tend to pile up and form metallic lithium on the outermost parts of the electrode. This is bad as it means a permanent loss of capacity, that lithium never gets released back during discharge. Also, the lithium can form dendrites that can end up piercing the separator between the electrodes causing a short and potentially a battery fire.

Some specialised prismatic cells have been designed for operation at lower temperatures, but they say if used below freezing to reduce charge rates to C1/20. I would not be happy to advise e-bike users with a blanket "yes it's fine to charge your bike below freezing with the supplied 2 A charger". People have all sorts of different pack sizes and chargers and different BMS controls etc. I think people have to be careful and see if it is appropriate for their particular situation. Take a 4p pack made of 2.5 Ah cells, C1/20 is a lot less than what a 2 A charger would supply.

The e-bike batteries I have bought have always advised against charging below freezing.

As a minor aside...Just because the Shetlands are on a similar latitude to cold places does not mean it gets so cold in winter:

Winter in Shetland - FAQs | Shetland.org

Alex Garrick Wright runs through some of our most frequently asked questions about life in Shetland during the winter, and explains that, far from it being cold, snowy and isloated, winter in Shetland is suprisingly mild - if a little breezy.

www.shetland.org

Agreed, ideally never charge below freezing point, but the point I am making is that one doesn't need to fret about this too much, especially in our climate, as your comment on the Shetlands shows.

Most of us the UK rarely get any chance to charge below zero degrees, since even our sheds and garages rarely get enough below to destroy cells, especially since the charging itself generates some heat within the battery casing.

Here's our two members living and pedelecing far north of the arctic circle in Norway: