Can You Charge Rechargeable Batteries with Any Charger?

Recent technological improvements in rechargeable batteries have created a revolution in electronics. That’s a good thing for the electronic devices we use, our wallets, and the environment. But with the many different kinds of rechargeable batteries available, it can be a challenge to determine which charger works best and in which situation.

Not all battery chargers work with all batteries. There are considerable differences in material composition and electrical capacity between rechargeable batteries, and using the wrong charger can damage the battery and possibly cause an explosion. Always use a battery charger that is designed for the chemistry type of your rechargeable batteries.

It’s a bad idea to charge a battery with a charger that you are not certain can accommodate. It’s possible to cause a fire with the wrong battery-charger combination, and acid leaks are a risk for larger lead-acid batteries. Good chargers will be clearly labeled as to what batteries they’re associated with; if it’s not clear, don’t use the charger.

Why Rechargeable Batteries and Chargers Aren’t Always Interchangeable

It might seem like any old charger will work, so long as the battery fits in it. However, this isn’t the case. The direction above about matching the charger to the battery chemistry is great, but if you want to get this right, just read through briefly to learn how a rechargeable battery works.

How Rechargeable Batteries Work

The reason you can’t use any charger for all rechargeable batteries comes down to chemistry. Batteries work by placing two materials with a differing electrical charge close to each other, separated by a barrier. One of these materials, the anode, wants to give off electrons and donate them to the cathode, the nearby material that wants to take the electrons.

This flow of electrons across a wire or an electrical circuit, for example, generates the electricity you use from the battery. This flow can be reversed in rechargeable batteries, which replenishes the electrical potential between the two specialized materials. This is recharging. The optimal recharging rate is determined by the quantity and quality of the materials in the rechargeable battery.

The important point here is that different rechargeable brands and types use different materials to create their electrical potential. These materials vary by the size and the intended use of the battery. Rechargeable batteries for use in a car or boat or other larger-scale purposes require materials very different from consumer electronics.

Rechargeable Battery Types: Liquid Core and Solid Core – What’s the Difference?

Rechargeable batteries can be broken into two categories: liquid core and solid core. Liquid core rechargeable batteries include 6V or 12V classic lead-acid car or boat batteries, which tend to be larger and higher-power applications. Although these batteries are overcharged, the acid-filled cells can explode when an inappropriate voltage is applied.

For consumer electronics and electric cars, rechargeable batteries are solid core. Smaller rechargeable batteries come in standard sizes like AAA, AA, or the rectangular 9V. Batteries in cellular phones and electric cars use ionized lithium, which has come into increasing use. Other solid core rechargeable batteries may combine nickel, cadmium, or other metals.

Each material combination requires a specific rate of electrical charge to recapture spent electrons and, potentially, a different charger for each type. Fortunately for battery consumers, many sets of rechargeable batteries include a suitable charger. When the choice of which charger to use is less clear, there are a few clues to bring the right matching to light.

How to Figure Out Which Batteries Work With Which Chargers

What Are NiCad and MiMh Chargers?

Most consumer rechargeable batteries, including the cheaper brands like Energizer (also on Amazon), are made of combinations of nickel and cadmium (NiCad), nickel, and metal hydride (NiMh) or ionized lithium (lithium-ion). NiCad and NiMh have been on the market for a longer period. They are made by a wide number of manufacturers and are usually clearly labeled on the battery’s body.

NiCad and MiMh chargers are also labeled as such and can often charge both types of rechargeable batteries. They vary in the range of sophistication from very “smart,” being able to detect with type is connected and deactivating when charging has been completed, to very “dumb.” The dumbest chargers of this type will charge a battery for as long as it is connected. The “dumb” ones are the problem since they may overcharge and damage rechargeable batteries. But with off-brand chargers, it’s not always clear if they have any smarts in them to prevent overcharging.

What Are Lithium-ion Batteries?

Lithium-ion rechargeable batteries are more powerful, last longer, and subsequently hold a higher degree of engineered materials. Lithium-ion chargers, in turn, require more sophistication, as overcharging lithium-ion batteries can cause the battery to explode. All chargers of this type enter a “trickle-charge” mode when the connected batteries have charged.

Lithium-ion rechargeable batteries should never be charged with a charger designed for NiCad or NiMh batteries. In addition to a difference in rate and strength of charging current, the NiCad or NiMh charger may not necessarily be able to deactivate once the attached battery has been charged up. If left alone, this arrangement could cause the lithium-ion battery to explode.

How to Put Your New Battery Knowledge to Work

The key to working around this puzzle is to look at the labels of the batteries. All batteries seem easy to use, and all look and work nearly identically. In rechargeable batteries, despite their resemblance, can behave differently when connected to a battery charger. Read the labels, use the correct charger, and when in doubt, take a few minutes to do the additional research to confirm your charger is designed for your type of rechargeable battery.

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