Confessions of a battery glutton: battery hacks to save time and money

By Jean-Jacques DeLisle, contributing writer

I remember growing up as a kid and always suffering from the dead-battery dilemma. Everything seemed to require batteries, and they were always running out. From Gameboys to buzzing and flashing kids’ toys, my three siblings and I could never get enough batteries. We also lived in an area prone to weather-related blackouts, tropical storms, and hurricanes, so we also always needed a ready supply of AAA, AA, C, D, and even E batteries.

In times of nostalgia, I have wondered how much less frustration we would have had about batteries if we had the internet and handy life-hack blogs like these. Now I no longer need to wonder, as having a child has renewed my constant need for batteries, which brought back the battery dilemma. The below tips help me save time and money and also prevent unnecessary baby boredom.

Image source: publicdomainpictures.net.

Introduction to batteries

As a quick battery primer, alkaline, nickel-metal hydride (NiMH), or lithium batteries are chemical energy storage cells. Electricity is released when there is a load on the battery, which means that there is an energy-absorbing connection between the anode (negative) and cathode (positive) ends of a battery. The chemicals in the battery cell undergo a reaction that turns chemically stored energy into electricity, and suddenly, your long-dead Furby comes to life.

For NiMH and lithium batteries, running electricity in the opposite direction efficiently reverses the chemical reaction, thus recharging the batteries. Alkaline batteries don’t recharge as efficiently, which makes their useful life drop significantly each discharge-charge cycle. The gasses released when alkaline batteries are creating electricity, specifically hydrogen, also change the structure of these batteries, even making them dangerous to recharge.

This is why I pretty rapidly bit the bullet and purchased long-life rechargeable AAs and AAAs. The cost benefit of having a few reusable batteries with better performance certainly beats the environmentally painful army of alkaline batteries that I would need to entertain my child as he grows. However, it can be beneficial to keep some alkaline batteries around for emergencies, as alkaline batteries’ energy loss in storage is only about 2% per year, whereas NiMH or lithium can be over 50%. Now for some quick tips.

How to know if a battery has charge left

Unlike modern smart gadgets with built-in rechargeable batteries, most batteries don’t have a handy indicator. As not all batteries discharge at the same rate, sometimes a single battery in batch is what causes a device not to run. Thus, replacing the battery could be the most cost-effective way of keeping that device running. There are several ways to test this for alkaline and rechargeable batteries:

● Get an analog or digital multi-meter, set it to DC voltage measurement, and put the red probe on the cathode (plus) and the black probe on the anode (minus). If the battery is healthy, it will give a reading very close to 1.5 V for standard cell batteries, 9 V for 9-V batteries, and within about 10% for other batteries rated voltage. As the voltage of a battery drops off rapidly as the available charge approaches empty, any battery with much less than the rated voltage is probably on its last legs.

● Some batteries come with built-in or included battery testers, which essentially do the same thing as the multi-meter, just with a hopefully easy-to-read gauge. Dedicated battery testers can also be purchased, though multi-meters aren’t much more expensive and are much more useful.

● The alkaline battery drop test! Yes, fully charged alkaline batteries tend not to bounce and make a solid “chuck” when dropped from a few inches on a flat service. Depleted alkaline batteries are often structurally changed from the expanded hydrogen gas inside and will likely bounce and make a hollow “thunk” sound when dropped.

● Rechargeable battery stations often have indicators if the batteries are charged or not, and these can often be used to check if the charge level is full or not.

● Keep swapping the batteries until you get a working combination. Though potentially time-consuming, this is the least complex way to test for battery charge. Using a known good battery, just swap each battery in the device with the known good battery, and when the device works after a swap, you know that you have found a bad battery.

How to keep batteries alive longer in storage

Essentially every battery type suffers from leakage current, or phantom current, and loses charge over time. This is unavoidable, even when storing batteries in cool temperatures, such as a freezer or refrigerator. However, sometimes the storage method allows for metal contact between different batteries and can cause discharge. This can also cause dangerous overheating, leakage, chemical reactions, and even explosions. This is why it’s often advisable to store batteries in such a way that they are insulated with some type of non-conductive material, such as common cellophane.

Other storage tips include:

● Removing batteries from electronics that will be unused for over a week, or more, to prevent phantom drain in the electronic device itself. This also can prevent corrosion and chemical leakage that could damage the electronic devices and healthy batteries.

● Keep batteries in a cool, dry place. Moisture is an enemy to batteries, and common desiccants, such as rice, can be used to keep batteries dry. Just make sure not to eat the rice later!

● It’s best to store batteries fully charged as many alkaline batteries and rechargeable batteries won’t be useful after they lose over a certain percentage of their charge.

Can I interchange battery sizes?

The answer to this is yes, as long as the battery voltage is the same. For 1.5-V batteries, they can all be interchanged with enough conductive material to make the connections and ingenuity. However, the size of the battery corresponds to the amount of energy in the battery, and smaller batteries will run out faster than larger ones. Common change, pennies, nickels, dimes, and quarters, along with folded up tin foil, can be used to fill up the gaps or “bridge” the connections between battery and device terminals that don’t quite match. Also, several lower-voltage batteries can be connected in parallel to make larger-voltage batteries, such as 6 AAs, AAAs, Cs, and Ds can be combined to make a rather large 9 V.

Using batteries as a touchscreen stylus

I was surprised by this when I first saw it but eventually realized the sense of it. Yes, the anode terminal on a battery can be used as a touch device on a capacitive touch screen like any other conductive object. This is because your body’s capacitance “transfers” through the battery casing.

Can I start a fire with a battery?

Yes! In a pinch, all that is needed is some wire or metal foil connecting the two terminals of a battery. Both the battery and the metal in between the batteries will get very hot and may even get hot enough to start a fire. Be careful, however, as the batteries themselves might get hot enough to explode or release toxic/flammable gasses.

Are there bad battery tips?

Indeed, there are.

● Some online videos suggest that you can charge batteries with other batteries. Though this is true, it isn’t a good idea for several reasons. Let’s compare the energy in batteries to water in buckets. If you have an empty bucket and a full bucket, you can fill or “charge” the empty bucket with some of the water from the full bucket. However, you will spill some water and then have less energy than when you started and have two less-than-half-full buckets. It’s the same with batteries except that you can also cause heating and toxic gas leakage that may lead to fire or explosions. Not worth it in all but the most extreme cases.

● Cutting open 9-V or 12-V batteries to get smaller batteries out of it. Some online videos show time-lapsed captures of dissembled 9-Vs and 12-Vs revealing a hidden wealth of button-cell and AAAs inside. Though appealing on the surface, this may not be a good idea. Disassembling a battery takes time, effort, and tools and can destroy a battery and cause personal injury. Though there may be useful-looking batteries inside, they often have less watt-hours (Wh), or amp-hours (Ah), of energy in them, making it a less cost-effective endeavor.

● Harvesting useful parts from batteries. Though this is entirely possible, it usually isn't a good idea. Batteries are constructed out of energy-dense and toxic materials. They often aren’t safe to handle outside of the original packaging, and the disassembling process is dangerous and time-consuming itself.