Mount Evelyn DX Report: LITHIUM-ION BATTERIES DESERVE RESPECT

LITHIUM-ION BATTERIES DESERVE RESPECT

Last week, on a Yahoo radio hobby forum, I read some misinformed comments about lithium-ion batteries. Things such as
1) they don't explode anymore,
2) if they do explode, then it's only during charging,
3) people's concerns over Lithium-ion batteries are exaggerated or unnecessary,
4) commercial versions of lithium batteries (whatever THEY are!!) are a problem, whereas personal household-style batteries are fine,
5) the cheap batteries are just as good as the expensive ones.

.....etc, etc.....

All of these claims (and more) show that some people are not aware of the need for care when handling lithium-ion batteries.

The chemical elements that make up a battery are compartmentalised for both their correct functioning in creating the charge and for safety reasons. Should those different chemicals come in contact with each other, adverse reactions can result. Even a leakage of a few molecules from one chemical within the battery case to the electrolyte or other chemicals could possibly cause reactions that lead very quickly to thermal runaway.

Sure, when expressed as a percentage of total units manufactured, the failure rate for lithium-ion cells is very, very low. Samsung claimed that of all the ill-fated Galaxy Note 7 phone batteries sold during their release in 2016, less than 0.1 percent were faulty. Now, that might seem like a very small number. But if Samsung is selling millions of phones, then 0.1 percent is actually quite a large number of potential battery failures!

Several years ago, a friend of mine reported that her son's Apple Macbook caught fire. He was out of the house, the laptop computer was charging, and smoke was pouring out if his bedroom! It was very lucky that she was home to catch this and put out the flames before the house burned down! She sent me a photo of the smoking wreckage:

A Macbook battery fire nearly caused a disaster in the home!

Now, there's lots of complicated science surrounding battery technology that can be readily accessed by a thorough Google search. So it is not my intention to delve into that here.

However, a recent easy-to-understand article called "The science behind exploding phone batteries" from online tech site The Verge offers a simple and helpful introduction to several current issues with lithium-ion technology.

During the holiday season, batteries are an item on many people's shopping list for powering those new gifts! Here are a few tips worth remembering.....

Rob's 10 tips for taking better care of your batteries:

1) Lithium batteries do not need to be fully charged. A partial charge will avoid undue wear and stress on the cells over the long term.

2) Stop using the battery or the charger if either gets excessively hot during the charging process.

3) Continuous charging (over-charging) on a daily basis will quickly shorten the life of the battery.

4) Turning off the device while charging the battery allows the battery to reach the required voltage without parasitic loads being placed on the battery and charger.

5) Charging should be done at moderate temperatures i.e. not below freezing or in temperatures of greater than 50˚C (122˚F).

6) If the device is going into storage for some months, give the battery a half-charge.

7) Resist the temptation to buy very cheap batteries and chargers. They are usually cheap for a reason! Use only lithium batteries with proper protection circuitry and a good quality charger with appropriate cut-off circuitry.

8) Batteries should not be charged in unmonitored locations. I've read some horror stories recently, so now I never leave home with any chargers left on!!

9) Do not short-circuit, drop, crush, penetrate with foreign objects, apply reverse polarity, or disassemble battery packs. The electrolyte is highly flammable and battery rupture can cause physical injury. (Sitting with your cell phone in your back pocket is NOT a great idea.....unless you want a VERY warm rear end!)

10) Use a foam, CO2 or dry chemical extinguisher for a lithium-ion fire. If the fire cannot be put out, allow the pack to burn out on its own, ensuring that the area around the fire is controlled and safe.

Hopefully, these few tips above will act as a reminder for everyone to take great care with these very convenient little highly-charged packets of energy!

(These notes came from a much longer workshop I presented to my local photographic society in 2015.)

73 and good DX to you all,

Rob Wagner VK3BVW