Cold Weather Charging in Outbuilding

[Sheffield_Tiger]

I live in a rented house and have a contractual agreement with the landlord that I am fine to store my bike in the house, but the battery must be charged in the outhouse (which has power but no heating). And I get that, I discussed it with the landlord to assure him I'd researched the brands behind the fires and sourced a reputable battery, so I think the arrangement is fair.

Is there any harm in wrapping the battery loosely in a lage old towel whilst it's charging overnight in ~0° temperatures? Or maybe construct a vented insulated box to protect it from the cold?

What do othe outdoor/shed/outbuilding chargers do?

 

[fossyant]

I recon it will be fine just charged without being wrapped - it will warm up through charging. Safer TBH.

 

[ebikeerwidnes]

It will keep itself warm as it is charging
wrapping it up might cause it to overheat if anything

 

[wiggydiggy]

I don't charge it outside, the manufacturer (Bosch) specifically mentions how ideally it should be charged and stored at room temparature, and to consider using thermal protective covers for long winter rides.

You could borrow an idea from home brewing, over the years I've built several boxes just out of cardboard that I'd put over the top of demi jons to keep the temparature up. It'd be large enough not to touch the battery direct and you'd only need to cover the outsides with bubble wrap or cork tiles to add extra insulation.

Can you at least store the battery inside after charging though?

 

[ebikeerwidnes]

Are there some mats that you can get for green houses to keep plants above freezing??

I am no gardner but I seem to remember seeing something like that

 

[sheddy]

Current advice is not to charge an ebike Li-on battery unsupervised

 

[wiggydiggy]

Current advice is not to charge an ebike Li-on battery unsupervised

I mean we don't need to sit there watching it, but this is the most relevent:

"It’s vitally important that you charge batteries only while you’re awake and alert so that if a fire should occur you can respond quickly. Do not leave batteries on charge while you are asleep or away from the home."

https://www.gov.uk/government/publi...-cycle-users/battery-safety-for-e-cycle-users

Theres other good advice in there worth reading.

 

[ebikeerwidnes]

I have started using a timer when I charge LI-Ion batteries
it is only a cheap one but I just set it so that it stays on for "long enough" but will be off by the time we go to bed

Then if I forget it is not charging - although having pratted about with the charger Plus the timer I generally remember anyway!

 

[CXRAndy]

I live in a rented house and have a contractual agreement with the landlord that I am fine to store my bike in the house, but the battery must be charged in the outhouse (which has power but no heating). And I get that, I discussed it with the landlord to assure him I'd researched the brands behind the fires and sourced a reputable battery, so I think the arrangement is fair.

Is there any harm in wrapping the battery loosely in a lage old towel whilst it's charging overnight in ~0° temperatures? Or maybe construct a vented insulated box to protect it from the cold?

What do othe outdoor/shed/outbuilding chargers do?

I would buy a tiny heater, because batteries will suffer from cold. Keep the battery above 10°C more towards 20°C. . This will protect from frost. A small enclosed cabinet will keep energy costs low whilst giving necessary temperature.

When riding in winter get a neoprene jacket to keep the battery warmer, protected from wind chill. This increase range to more summer levels

 

[Sheffield_Tiger]

I would buy a tiny heater, because batteries will suffer from cold. Keep the battery above 10°C more towards 20°C. . This will protect from frost. A small enclosed cabinet will keep energy costs low whilst giving necessary temperature.

When riding in winter get a neoprene jacket to keep the battery warmer, protected from wind chill. This increase range to more summer levels

Ooh, i have an old neoprene arm strap from an old injury that will do the job!

Memories of growing up with an outside loo, we hung a paraffin lamp to help stop pipes freezing. Might be an option...

 

[Tenkaykev]

Not a bike battery but my home battery lives in an outhouse. It is LiFePo and just like a bike battery doesn't like the cold as it affects the rate of charge / discharge as well as capacity. I have rigged up a small thermostatic fan heater with a wireless remote plug / energy monitor. It is currently using a little under a kW and this has pulled up the temperature a fair bit over the last hour.
I've read of others with a similar set up using a greenhouse heater, and one enterprising person apparently has an electric blanket secured with a couple of bungee cords around theirs 😮

 

[Gwylan]

Fridge box and a hot water bottle could be way to go

Range of my batteries slump from >60 km to about 40 km in the winter.

Reflecting, I have a hand made, bodge up, slow cooker off the boat. Made from a polystyrene fish box. That has heater pads and a thermostat, runs off 12 volts.
Hard to know how I might measure how effective such an arrangement is.

Maybe an insulating jacket for the battery when it's on the bike might be more use.

 

[richtea]

Don't do it!
Charging below 0°C is not good for Li-on batteries. Discharging it below 0°C is fine, though (i.e. riding an ebike).

Reference (there are plenty of others):
https://batteryuniversity.com/article/bu-410-charging-at-high-and-low-temperatures

"Many battery users are unaware that consumer-grade lithium-ion batteries cannot be charged below 0°C (32°F). Although the pack appears to be charging normally, plating of metallic lithium occurs on the anode during a sub-freezing charge that leads to a permanent degradation in performance and safety. Batteries with lithium plating are more vulnerable to failure if exposed to vibration or other stressful conditions. Advanced chargers (Cadex) prevent charging Li-ion below freezing."

 

[Sheffield_Tiger]

Hmm... perhaps I should change routine and charge at work. Since we sell a few ebikes, charging of ebikes is never going to be a no-no. That might be the best route until i rig something up to keep it warm/insulated.

Useful info from all who replied, thanks

 

[CXRAndy]

Re heating. Many years ago we had a guinea pig that lived outside. We used to put hot water bottles several times a day in winter. I decided to do something with more of a constant heat. I bought an electric radiator element, embedded in poured concrete under the little animals cage. I then wired it to a light triac control. I adjusted the settings to give a comfortable 15-18C floor temp for Guinea pig.

There are many ways to achieve local heating without spending big money.