Is battery charging REALLY that dangerous??
 

Just got my Luna BBS02 kit and bottle battery in today! Can't wait to start installation! :love:

I got the Luna 52V smart charger, and in the little manual it says to not charge the battery in a house, and preferably charge it inside a BBQ grill or "lipo safety bag". Really? I assume they mean put the battery itself into the grill or bag in case of fire, but the charger should be outside for cooling and air flow, right? That seems kind of crazy. I don't think I want my battery sitting outside, especially with it being quite cold this week. What are others doing for charging, and charging safety?

Lithium Ion batteries are notorious for overheating when charged or discharged too quickly. (especially cheap, poorly made ones).

But this shouldn't be an issue when charging with the factory charger which is (should be) properly matched for the right charging rate. So, either the maker knows that their charge are crappy and tend to overheat the batteries, or it's simply a boiler plate warning on par with "place in 350° oven for 1 hour........WARNING may be hot".

In your shoes, I'd charge it outdoors just in case, but not worry about the rest.

So I couldn't charge when it's raining?? Seems like a lot of trouble, considering we charge various things all over the house and office - camera batteries, bike lights, phones, tablets, laptops. I read somewhere that Li-ion is less volatile chemistry than LiPo batteries.

So what about these Lipo safety bags, or another website suggested any sort of fireproof container like an ammo box would work also. Isn't heat buildup a concern? Isn't it better for the battery to have airflow all around while charging?

you shouldn't put all Li chemistry cells in one bag.
LiFePo chemistry is for example very safe to charge,
Lithium Polymer /used widely in RC hobby/ are notoriously dangerous and famous for fires.

This is about the combination of the battery's size and quality. Small appliances aren't as vulnerable to overheating because they have favorable surface/volume ratios, but even then there have been incidents.

On a larger battery, both the likelihood and consequences of overheating are heightened, so it's something to think about. As I said, I suspect there's some sort of CYA boilerplate here, especially following those highly publicized hoverboard fires last year.

So, use some judgment. If you have a garage, charge it in the middle of the concrete floor, maybe standing it on an iron trivet for even more protection. Or use other reasonable precautions, especially at fist until you have a sense of how hot it actually gets. However keep in mind, that even a battery that' been fine for months can develop an internal short and overheat, o charge and store it where the consequences of even a low probably fire won't be severe, ie. don't charge it on the carpeted floor of your basement.

FWIW - here's more on the subject. After that you're on your own.

Well this is the bottle battery pack from Luna Cycles, using Panasonic 18650 cells, and I'll be charging with their "smart" charger which allows me to choose the charge rate from 1-5 amps, as well as the charge percentage from 80% to 100%. I should hope that it will be safe. I read someone say they never charge their e-bike battery unattended or while sleeping, so I'll see how it goes for a few hours while I'm at home and awake, to monitor things.

There's quite a bit of difference in energy content - as well as the number of cells, and with that the risk of failure - between an ebike battery and a phone or similarly sized item.

It's the difference between the general and the specific.
Keeping a battery reasonably cool is generally a good idea. A certain amount of heat build-up mainly accelerates ageing - number of charge/discharge cycles a bit. But with a suitable charge rate the battery shouldn't cook anyhow.
However, good ventilation isn't that good protection against (the layers in a) single cell shorting out, overheating and bursting.

The sad thing today is that everyone is playing the CYA game about everything. So, you have no way of knowing what is boiler plate and what they intend as a serious warning.

It's almost as if we now need language in some warnings reading "WARNING, this warning is NOT CYA boilerplate, and there's a very real hazard here if you don't pay heed"

I’ve known those Luna guys for years (well before the store came out), and this bit of info looks to have come from the days when LiPo was popular (see post #4). Sane people only charge those in grills.

I designed a LiPo system but never bought it because I didn’t want to charge in a BBQ grill. People used to tell me to use LiPo back in the day, but I’m certainly not going to charge a dangerous pack at work!

The Panasonic 18650 type cells are much safer. And well, you read the papers. The news last weekend was a 3 year old who died because someone charged their lithium batteries in a hoverboard at home. Still, a name brand cell like this is “reasonably” safe. Charge it over concrete if you can. Smoke detector would be a good idea too, for your charging area. Be aware. If it is damaged, be careful.

I'm a big fan of Luna, but they resell many of their batteries (assembled in China, I think); accordingly, I'm in the next room when my batteries are charging. May not save the house, but everyone should get out in time. AFAICT, the "majors" don't have a similar requirement, so I feel safer charging their batteries, but still keep the system nearby.

It's a small, but real risk. What makes our batteries any better than the several dozen hover board units that caught fire in North America last year? I guess they're not getting knocked around. Technology is the same. BMS. 18650 cans. Maybe the resellers do a better job picking quality makers.

I put my charger on a timer, in case I forget, leave the house or fall asleep. I also charge in a clear space on the floor of my garage. I've got three dolphins and two shrink wraps. The latter go in a metal tool chest when not on a bike.

On the other hand, I've go two Ryobi's for my lawn tools that I will leave on the charger. I trust the UL label.

Keep in mind that one of the largest ebike dealers in the Midwest had a battery catch fire in their showroom a year ago.

Well I've had the battery on the charger for about 4 hours now, with the switch set to 3 amps, and 100% as recommended by Luna for the first time charging. The battery itself is sitting on the tile floor by the kitchen table. It's currently at 58.5V and the battery casing is 100% cool to the touch, not even warm in the slightest. :thumb:

Should get to 58.8V.

The fan on the charger shut off about 20 minutes ago, 2nd light turned from red to green, and the display is shifting between 58.4 to 58.5 volts. I'm guessing it's in the process of balancing the cells now?

AIR that's what my Luna battery did too (been 18 months, so not exactly sure). It's been robust; I couldn't ask for better service from one).

You all know there is quality product and then there is "cheap crap." Hoverboards are part of the latter category.

I see no reason to take extraordinary precautions when using a quality product. Just the same I wont be careless about it either. I charge my batteries indoors all the time. But I also charge them on the bike in the garage as well.

I dont leave them unattended for days plugged into the charger, like the power tool batteries already mentioned.

I would trust Luna's product.

I heard about the fire in the e-bike store as well. It WASNT caused by any of their normal product line. It was from a low quality product that happened to be in their store.

-SP

The danger is thermal runaway: a cell becomes unstable and fails at a high temperature (like around 300°), vents combustible gasses, propagates to other cells. It's sudden and spectacular. Well designed battery packs with quality batteries, overcharge protection and a good charger should not pose any significant risk of this happening. Unless there is a material defect in the batteries, and something has damaged the protection circuitry preventing shut-off, it will be extremely rare.

I've seen the recommendation to NOT charge at freezing temperatures or below, because even though it may seem to charge correctly it causes internal damage to the batteries. I think I would heed that advice, especially when considering charging out-doors. My inclination, not advising and do so at your own risk, but personally I'd probably set up some kind of metal box for charging and do it in the garage, or else inside where I could keep an eye on it.

I charge my LIthium Iron Phosphate chemistry 12S battery packs for 15 years at minimum inside my house .
NO BMS on any of my packs just HighVoltageCutoffs HVC, but
again
this is LiFePo chemistry , I would never do it with Lithium Polymer.

Between the BMS, controller HVC/LVC and the charger HVC/LVC provides plenty of safety while charging . Even if one of the three fails, this will cut off battery current. Only problems I ever heard of with any type of battery charging is "user error. Which includes manufacturer error. Stay safe and I'm happy to read your post .

My Schwinn Tailwind is just pedal assist only and its Lithium Titanate battery has small capacity compared to other types but was reputed to be very safe compared to other lithium ion battery types. A bit of research verified this, but I still charge on the concrete floor of my basement workshop or garage floor. FYI, here is a bit of what I found on the type:

"Lithium titanate (Li4Ti5O12, referred to as LTO in the battery industry) is a promising anode material for certain niche applications that require high rate capability and long cycle life. LTO offers advantages in terms of power and chemical stability, but LTObased batteries have lowvoltage: 2.5V vs. LiCoO2 and 1.9V vs. LFP

Nevertheless, the lower operating voltage brings significant advantages in terms of safety. Further, these batteries can be charged fast. Data shows that these batteries can be safely charged at higher than 10C. This means the battery can be charged in less than 10minutes. The LTObased batteries also have a wider operating temperature range and a recharge efficiency exceeding 98%. Although the energy density of LTO batteries is low compared to other lithium ion batteries, it is still higher than lead acid and NiCad batteries" Don

Anyone living in cold weather climate this time of year noticed the effect of cold battery's appear to be less powerful? I've noticed that my bike gas more range and more power on the warm days . I've heard that cold temperatures don't have a permanent impact on battery life. I've also noticed my charger light turns green a few bolts shy of its normal peak charge.

^ What he said. A good safety method is to charge batteries under or close to one of your smoke alarms, but I wouldn't expect any issues with a good charger and quality battery build.

So far, probably not. (read, will not deny)

Homeowners is general liability insurance which also covers owner stupidity, except for specifically listed exceptions. So it will cover an accidental battery fire the same way it covers one started by smoking in bed, your children playing with matches, an overload circuit, a heater tipping over, or set too close to curtains, etc.

...and it wasn't even charging! Hmmm...