Safe indoor battery storage?

[handlebar]

Lithium is pretty terrifying when it goes sideways. Its like a caged lion.

Vapers have had fires because some of the devices come with unsafe 18650 cells.

https://www.dnkpower.com/why-18650-battery-explode/

These experts say the modern 18650 battery is quite safe if it's a good brand. They're made not to short internally. They have valves to prevent explosion. They have internal circuitry to prevent dangerous current in or out.

They recommend charging at 20 to 26 C. Too cool isn't harmful, buy you may not get a full charge. I've sometimes charged in the garage, but I guess it's not a good idea.

They say not to use these batteries in humid conditions. How would you avoid that on an ebike? They don't say why or how humid.

[John Rose]

... I am considering getting a RadMini Step-Thru 2 ...

I wish I know about this before I topped off my Ryobi batteries for my mower.

Well, that's a double coincidence. I recently bought both a RadMini ST2 and a Ryobi cordless electric mower.

[handlebar]

Well, that's a double coincidence. I recently bought both a RadMini ST2 and a Ryobi cordless electric mower.

That reminded me to check the lithium battery of the hedge trimmer I bought in 2022.

The nicad battery on my B & D hedge trimmer lasted many years. When it deteriorated, I bought a B & D nimh battery, which was supposed to be a replacement. I soon had trouble, so I bought a brand that was supposed to be better. Same thing. I thought it must be the charger. New charger, same thing.

It turns out, the B & D charger, which was supposed to be good for both types, would drain a battery at a few milliamps. When the battery came down to a certain point, the charger would come on and top it off. That seems to be the best way to maintain a nicad and why the original battery lasted so many years. With nimh, there's a drain current but the charger never comes on to top it back up. It's best not to leave the battery on the charger. B & D never explained that. They surely made a lot of money manipulating consumers into replacing batteries and chargers.

Several times a year I needed to cut back an enormous hedge with hand tools because the electric trimmer wasn't aggressive enough. When I saw a more aggressive one marked down, I bought it even thought it was B & D. It's lithium. B & D said to recharge it after each use. I wasn't inclined to believe their battery advice. I'd charge it only when it began to slow down.

Your mention of a Ryobi mower made me think. I read 16.6 volts on the 20 volt battery. I don't know what kind of cells the B & D has, but suppose it's 5 in series, which could be 20 volts fully charged and 18.5 nominal. I put it on the charger for an hour or so, measured 18 volts, and it was still 18 when I checked after it had sat an hour.

If they published state of charge vs voltage charts for particular batteries, I could see if a battery was suitably charged for storage.