nofars.net

Todd, K1KVA spoke about breakthroughs in battery technology at the November 2020 NOFARS meeting.  Rajesh, K4SK has posted on YouTube

https://www.youtube.com/channel/UCKO1f6BWEDAt06y8YyYeSnw

Additional notes from Todd:

Lithium ion and Lithium Iron Phosphate battery source....surplus and new....    https://batteryhookup.com/

I have had good service from them so far, they vet the junk and reject cells from the good stuff plastered all over ebay and elsewhere.

A suggested charger controller using a Digikey IC chip:    https://www.digikey.com/en/articles/a-designer-guide-fast-lithium-ion-battery-charging     

I will likely be purchasing a few soon to breadboard into a battery charger.

YouTube is chock full of experimenters building their own battery packs for ham, scooters and minibikes, solar "power wall" storage. 

Above all, be careful with these high-density energy storage devices.

Lead acid gel cells are relatively forgiving, but Ni Cad, Nickel Metal Hydride, and Lithium batteries have so much more current generating capability that you have to go the extra mile when thinking out your battery safety.   

Don't hesitate to put in extra fuses when stringing cells together. These cells have much to offer to the ham community, they are now in the price range of us mere mortals.

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RECHARGEABLE BATTERY SAFETY

By Ross Goodall, WD4NJV

There have been numerous reports of battery fires on self-balancing scooters and E-cigarettes.

Amateur Radio:

I have not been able to discover any fires caused by amateur radio rechargeable batteries or the charger units provided by the manufacturer.  I am thankful the ARRL testing lab performs extensive tests and reviews on some equipment offered for sale to the Amateur Radio community.

Self-Balancing Scooters:

Some airlines have prohibited self-balancing scooters on flights and the USPS has stopped shipments of self balancing scooters by air. According to the US Consumer Product Safety Commission there have been 60 reports of self-balancing hoverboards fires totaling over $2 million in property damages.  

According to sources, the fires started while charging, others while riding, and some just sitting unused at the time.  In a rush to get them to market the parts may come from thousands of interchangeable factories in China with limited or non- existent quality control standards.

Some fires on self-balancing scooters were thought to be caused by using a different charger that provided by the scooter and over charging.  The science on Lithium ion batteries is that the liquid inside is highly flammable and if the battery were to short circuit by overheating or puncturing the battery can heat up quickly and explode.  Sharp metal particles inside could affect battery integrity.

Some batteries were even found to have an overwrap stating a well-known brand name and or CE certification when the battery was not name brand or certified.  1

E-Cigarettes:

Fires from e-cigarettes can also be disastrous. “Obvious problems are lack of industry wide manufacturing standards and testing”. Very high or low temperatures can cause failure.  Well-made units have safety features built in.  Batteries taken out and carried in pockets with keys and coins can short our and cause a fire.   2

Safety protection on E-cigarettes can be built inside the battery or the unit itself.    Protection must be in one of these places and when batteries with protection are replaced, it must be with a battery that has protection built it.

References:

1    CNET:  Here are the reasons many hoverboards are catching fire.

2    NBC News Digital:  What’s causing some E-Cigarette Batteries to Explode?

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Even brief shorts--such as those created by an errant screwdriver blade, wire or other metal bridging the terminals--start fires instantaneously.  Burning insulation creates smoke, lots of it. BEWARE 

Proper Household Grounding

By Ross Goodall, WD4NJV

Recently our home had to be replumbed, changing from copper to plastic pipe. 

Several days after the plumbers left, I noticed a ground strap had been disconnected from the cold-water pipe supplying water to the water heater. 

This wire on the other end was connected the ground lugs inside the breaker box. 

Although I am not an electrician, I realized that this created a dangerous situation.  It was corrected by re-grounding the wire and the breaker box to a new ground rod outside.

If your home has been replumbed you should check if you have a similar unsafe situation.  If in doubt contact a licensed electrician.