There's been a good amount of discussion here regarding the hazards of charging batteries and fires. Most everyone that flies electric is aware of the potential for battery fires during charging especially if a battery is damaged and the charging is left unattended. Unfortunately, the risks of charging Lithium batteries used in the numerous tools e bikes and toys falls on the unaware public which has resulted in a recent upswing in household fires. I happen to be familiar with a company involved in the building rebuild following a recent e bike fire in my area. It turns out a boy was charging his e bike in his bedroom that caused fire damaging most of the home's interior. The insurance company is in the process of investigating the e bike's manufacturer to probably determine if the charger had the necessary protection to prevent runaway and overheating. With more and more of these products coming from overseas the question arises if they are safely made. In the case if this incident the homeowner has now questioned if the home will be safe to reenter after the cleaning and repairs. They are aware, due to the composition of lithium batteries when burned it creates a number of hazardous chemicals, many that are difficult if not impossible to remove. The insurance company and the remediator here are involved in extensive costly testing to resolve the situation. The bottom line here is battery charging that goes on everyday everywhere is becoming a major liability that well beyond flying our models. So, give thought to leaving your weed trimmer charging overnight or knowing the grandkids are plugging a charger into their electric car. The estimate to rebuild the home here is over $200K!!

Aside from the battery-charging issue, which is the owner's problem, electric motorcycles are a life threat to pedestrians, runners and pedal driven bicyclists like meyself and my wife.

A normal recreational cyclist goes 8-9 MPH routinely and 10 MPH with effort. Much slower uphill. E-bikes routinely cruise at 25 MPH and I paced them at 35 with my car.  Over a one and a half mile straightaway with a 35 limit an E bike outran my car, mainly aided by running stop signs and traffic lights which I obeyed. 

Twice the speed coupled with twice the mass equals four times the knetic energy in a crash.  Plus, a motorist crossing a sidewalk is used to scaning for traffic coming at 10 MPH, not 25.

E bikes are typically driven by older men who have lost their drivers licenses for cause or 12-year olds with more money than brains.  Sadly, action with come only after a serious injury.   

Hopefully, this fad will fade when the first generation of of Lipos won't take a charge and the price of replacement take over.

For our use, I always tell people just starting in electric the most important thing is to buy a very good charger from a name brand. The charger needs to be intelligent for various types of batteries, and sit on an flat surface too allow airflow for cooling. Use a battery charging bag as extra safe guarded and always be close by when charging.

Best,   DennisT

All good points. There's so much against the use of these e bikes you can write a book. It's not just fires but more importantly the age of the young kids using them. These young bikers are yesterday's video race car champions that just got off their skateboards only to jump on a motor-powered bike that will enable them to get over 20 plus MPH. I reopened the "fire thread" with a story of a faulty charger fire but more so because my 14-year-old grandson just got his $800.00 e bike for his birthday. All his friends have them so he couldn't live without having his own; and his is a moderately priced one. Checking it out I discovered he uses a lamp cord to power the charger that lays on the garage floor and is often swept away by foot when he's ready to go. He knows nothing about degrading the battery by fully charging it only to be left idle or running it down below 20 %. He needs work here for sure. He will lose use of the bike for a day if he's caught forgetting to use his helmet. Helmets are not cool he claims, "too hot to wear and a possible cause for an accident"...God help us!! I hope the state creates restrictions quickly on their use to a minimum 16 years similar to when a kid can get a drivers learner's permit. Anything younger is an accident waiting to happen. Just google the deaths of young kids using these e bikes. And lastly a replacement battery? That'll be a no brainer the parents will take care of, of course.

LiPo batteries are as safe as the person using them. With that said I will be migrating to Li-ions for various reasons but they are less volatile.

Li-ion batteries have less burst power but offer a longer duration compared to Li-po batteries that tend to be used in the model airplane area where a higher short term power output is desired. Li-ion batteries have a more flammable liquid electrolyte compared to gel filled Li-po batteries. Li-po will burn initially more intensely than Li-ion that tend to burn longer due to their metal sealed cases while Li-po batteries are foil wrap covered. Unfortunately, both types will generate high heat when burned and both will produce a variety of contaminates including acids dangerous to our skin and especially dangerous to the to the tissue linings of the lungs if breathed during a fire. And now with the increasing use of Li-ion batteries, improper disposal is resulting in waste hauler vehicle and dumpster fires. I think both are equally risky from a safety standpoint.

When I first starting in electric by in 2005, I was really concerned about the battery fire issue. At the time the A123 cells came out (these were used by DeWalt tools) that were pretty close to the Lipo packs and very safe no matter what the charge level. I used these for a few years as I was learning about lipo safety and the importance of the smart charger. If you are really concerned about kids not being careful when charging the A123 type pack is the safest as they can be overcharged, dropped, banged on all without a problem (that's why DeWalt uses them). I eventually switched to the Lipo's for the weight savings after learning that they were safe as long as you use a very high-quality, smart charge designed with the safety features and rates for charging Lipo's. Never had a problem.

Best,   DennisT

Batteries are as safe as the equipment and the folks using them. Buy good expensive gear, batteries and chargers.

If you buy cheap products and abuse them expect problems.

Use common sense.

Same with Nitro fuel, store it correctly and never have near heaters or open flames. It will burn you house down too.

I keep a EV parked right outside my garage. It has approximately 900 cells that charge every night.

I'm gonna say, never charge hobby batteries unattended, but commercial power tool type batteries are safe...until one of our R/C club members burnt down his garage courtesy of Dewalt! I'm told they were pretty warm from immediate past heavy use, but still I thought the chargers had temperature protection. Moral : don't charge any battery that is hot!

Cheers,

Steve M.

Quote from: Steve Manganelli on May 05, 2026, 04:27:54 PMI'm gonna say, never charge hobby batteries unattended, but commercial power tool type batteries are safe...until one of our R/C club members burnt down his garage courtesy of Dewalt! I'm told they were pretty warm from immediate past heavy use, but still I thought the chargers had temperature protection. Moral : don't charge any battery that is hot!

Cheers,

Steve M.

I'm sure that's a good idea, but Tesla's will "precondition" the batteries before charging on a road trip. Either heat up or cool down.
Lithium-ion batteries have a "sweet spot" for fast charging—usually between 104°F and 122°F.

This is embarassing, BUT, several years ago, when I first got into  electric models, I had a battery  pack that looked swelled and assumed (oh oh ) that it was from air puffing it up.,. SOOO, I took an xacto, punched the cover and wham. SMOKE like from a smoke grenade.. I kicked it out if the garage and my neighbor thought the whole place was on fire, It burned out and I tossed it into the creek behind the garage.. I think a Racoon stole it as it was gone the next morning.