Is it safe to leave ebikes parked in extreme sun

Hi everyone
I live in Australia where the weather can get extremely hot and anything exposed to direct sunlight is going to be fried. I have a Turnigy lipo pack inside a cheap fabric bag at the moment barely secured to the bike but I only use my ebike for short trips around town and never leave my bike unattended with the battery still attached which severely limits where i can take my bike and how long i can leave it. I want to upgrade to a 18650 battery pack such as a Hailong, triangle bag battery or bare shrink wrapped blue box type packs inside a black bicycle bag
(eg https://www.ebay.com.au/itm/48v20ah-Electric-Bike-Bicycle-eBike-Lithium-Ion-Li-Ion-Battery-for-1000W-1500W/113026636476)
but are these safe to leave parked outside during the day in the summer heat or even in shade? And which is the safest option? The solid hailong cases I would think are more secure but if it's safe enough I want to go with the bag option as that has more capacity. I don't want to start a fire unknowingly and get in trouble but at the same time i dont want to or cant carry around a bulky block of battery with me everywhere. Any Australians' experience would be particularly appreciated, or those who live in similar climates (Arizona?)

Also what would I do with the lipo once I no longer have any use for it and need to safely dispose of it

Since a pack like that isn't thermally coupled from the shell to the battery, i'd imagine it's okay, unless your area is so hot that it melts plastic or something

Maybe cover the bag or case with white or silver paint/material to keep the internal temperature lower in direct sunlight?

One thing to consider is that you should buy a battery with 2x-3x more output than you need so that it generates as little heat as possible through low internal resistance..

IE.. you want 40A? get a battery that does 80+

Batteries that have a lot of voltage sag ( high IR ) generate a lot of heat. That heat plus your ambient temperatures could be too much.

Solar gain temps aren't typically a safety concern, but a major calendar life decay accelerator, as the rate of decay doubles every ~10degC hotter. If you had a pair of the same ebike, and one was stored in a climate controlled garage, and one was parked in direct sun in a hot climate, it would be expected to see a 2-4x lifespan increase on the ebike kept in a climate controlled garage.

If you know your bike is going to be kept hot for extended periods, not charging over ~80% SOC would help reduce side reactions and gas internal gas production rates.

RC lipo disposal

Slowly drain them to 0v, leaving them plugged on a light (for an example). No matter the resistance that you are using to discharge them, it must draw low enough current to keep them cool during discharge.

Once all the cells are at 0v, they are inert and safe to send to recycling facilities.

MadRhino said:

RC lipo disposal

Slowly drain them to 0v, leaving them plugged on a light (for an example). No matter the resistance that you are using to discharge them, it must draw low enough current to keep them cool during discharge.

Once all the cells are at 0v, they are inert and safe to send to recycling facilities.

Click to expand...

If you have a safe place outdoors, a 5gal bucket of water you leave the cells in for a week also makes them safe for recycling.

Try a cover made from a roadkill auto dashboard sunshade. The silver bubble kind. Or use an insulated grocery bag, the one for frozen food. I worried more about the hot black saddle burning my butt out of the chute.

The fingers said:

I worried more about the hot black saddle burning my butt out of the chute.

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:lol: Yeah, i see how that could be the biggest concern.

Aussie here 8)

I'd try to park in the shade where possible. I wouldn't leave my ebike in full sun all day on a scorcher. An hour or two shouldn't hurt though

liveforphysics said:

If you have a safe place outdoors, a 5gal bucket of water you leave the cells in for a week also makes them safe for recycling.

Click to expand...

If I do that would the chemical reactions from the lithium and water make the water toxic or unsafe to dump just anywhere? Sorry new to battery technology

The water would not load with chemicals from the batteries, if that is what you ask. Yet, you would ideally add salt or calcium to the water, to make it conductive enough to drain the batteries. Water from a well is mineral enough. Water collected from rain is not mineral, and would take a very long time to drain your batteries, releasing micro bubbles of hydrogen. The calcium salt that is used for melting snow is cheap and perfect. Salted water is not polluted but it can’t be dumped anywhere, not where plants are growing at least. It would not pollute the soil, but it might take a while before new plants can grow, depending of the amount of salt dumped, the abundance of rain in your region, the porosity and drainage of the soil. Better dumping it on the street or the sewer IMO.