Safety idea for battery chargers

[Joe Jensen]

I’ve heard for years that lithium battery chargers are a major cause of house fires. So I’ve always tried to unplug them when not using. Of course I don’t always remember. So last night I put together a countdown timer with an outlet strip. Now when I charge I can just hit the 30 min button and forget about it.

[Maurice Mcmurry]

It is a big concern. A house close by burned down last month (E.V. plunged in in the garage) I like your idea but recommend a non household type of timer like a darkroom timer or an industrial, motor driven, count down timer. (speaking from experience, Fire department, Lawyers, and Insurance Companies will confirm).

[Joe Jensen]

It is a big concern. A house close by burned down last month (E.V. plunged in in the garage) I like your idea but recommend a non household type of timer like a darkroom timer or an industrial, motor driven, count down timer. (speaking from experience, Fire department, Lawyers, and Insurance Companies will confirm).

The timer causes a fire?

[Maurice Mcmurry]

If the that type of timer is used to control something with a fire starting potential they are not approved.
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[Matt Day]

Think li-on batteries are dangerous, Lipo batteries we use for RC cars are 100x more volatile. I store mine in an ammo container - will at least contain a fire, fumes and smoke on the other hand….

[Tom M King]

I don't like to leave home with a clothes dryer running either.

[Greg Funk]

If the that type of timer is used to control something with a fire starting potential they are not approved.
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Mid mo out of business! [Archive] - Mandolin Cafe Forum

He's just adding something out of an overabundance of caution. There's no requirement to shut off power to battery chargers and the risk for low voltage name brand power tools is very low. If you're worried, don't start charging in the evening. Leaving a battery in modern chargers is not a risk as the charger shuts off automatically when the battery is fully charged.

Most of the home fires are caused by low quality high voltage batteries used in e-bikes, scooters, hoverboards etc.

[Maurice Mcmurry]

I agree with Greg and approve of the added caution while charging battery's! Seeing a bathroom fan timer incorporated into a DIY circuit with safety as a goal will always be a no no for me.

[Alex Zeller]

I don't think battery chargers are in the top 10 for causes of fires. I suspect if they were a real issue there would be a lot more fires. How many houses have multiple phones plugged in charging every night? My guess is the number is above 90%. My shaver lives in a stand that' always plugged in. It's been more than 5 years now without issue. The wife has several kitchen gadgets that are always on their charger.

[Maurice Mcmurry]

Joe, I like your concern for safety and you have done a neat job on your charging station power supply. Those Leviton timers are rated for 15 and 20 amps. Either one should be good for a charger or two.

Timer specs from Leviton
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[Greg Funk]

I don't think battery chargers are in the top 10 for causes of fires. I suspect if they were a real issue there would be a lot more fires. How many houses have multiple phones plugged in charging every night? My guess is the number is above 90%. My shaver lives in a stand that' always plugged in. It's been more than 5 years now without issue. The wife has several kitchen gadgets that are always on their charger.

The risk with batteries increases with voltage. Higher voltage batteries require more cells in series. This is the reason hoverboards have issues. They use 10-14 cells in series and if the cells are not well matched it is possible for individual cells to exceed their safe operating range. With single cell batteries used in phones it's much simpler to protect the cell and keep it in a safe range.

Batteries constructed of cells from tier one manufacturers, Panasonic, Samsung etc, are less likely to have issues as the individual cells are closely matched before assembling the battery. Hoverboards or any battery using strings of inexpensive cells with questionable quality control have higher risk, particularly as the batteries age.

[Dave Sabo]

The issue with EV chargers causing fires almost always traces back to faulty installation. Usually a cheap receptacle and or mis sized wire. Which arcs, overheats and then causes combustion of adjacent materials. Being installed mostly in garages that also happen to have highly flammable substance in them doesn’t help.

[glenn bradley]

Good call. I’ve had a timer outlet for my chargers for many years. It definitely adds peace of mind.

[Randall J Cox]

I, like lots of you, have a little station set up for recharging batts. However, i don't leave it on overnight, its only charging when I'm in the shop. I take batt out and turn off all chargers with outlet strip switch. Nor do we leave the dryer running when we leave the house and I religiously clean out the lint trap of the dryer. Etc, etc. My son is a fireman and I've heard to many stories. Randy