Rechargeable batteries, of which the most common are NiMH (Nickel-metal-hydride), NiCd (Nickel-cadmium), Li-ion (Lithium-ion) and lead-acid (the type generally found in cars), they are a sustainable alternative to common disposable batteries. You can learn how to use a charger to charge smaller batteries for consumer electronics and other applications, as well as for your car battery.
If you want more information on how to properly charge the battery of your cell phone or mobile device, read this article.
Steps
Method 1 of 2: Use a Charger
Step 1. Get a charger suitable for the batteries you need to recharge
Rechargeable batteries are often recharged with an A / C (AC / DC) adapter, which you can plug into any standard home outlet. These devices come in a variety of sizes and allow you to charge batteries of all sizes, from AAA to D. Depending on the type of batteries you want to recharge, you can find the right charger at any electronics or hardware store.
- Some fit in different sizes, allowing you to recharge AA and AAA batteries using the same terminals. If you have a lot of different sized batteries, this would be an ideal choice.
- Quick chargers are similar to regular chargers, but often lack the charge control device that stops or slows the flow of current. They are very effective in recharging batteries quickly, but can significantly reduce their life.
Step 2. Use only batteries that are suitable for the charger
Never try to recharge disposable batteries, or you could risk corroding and damaging the charger. Only use batteries that are labeled "rechargeable" (sometimes also in English, "rechargeable"). If you have worn out disposable batteries, dispose of them properly and purchase rechargeable ones.
- NiMH batteries are common in consumer products, especially in power tools, while lithium-ion batteries are more common in electronic devices. Both types are in common use and both can be rechargeable.
- When using a set of rechargeable batteries for the first time, discharge them completely before recharging them. This will allow you to reduce the risk of the so-called "memory effect", which is the phenomenon whereby the battery drastically loses its charge capacity when it is only partially recharged.
- Use a battery tester to determine if the battery still has power before recharging it. Many battery testers are inexpensive, easy to use, and give an instant reading.
Step 3. Plug the charger into an electrical outlet
Most wall chargers should have a power light come on automatically, or there should be a power button / toggle. Make sure the power lights are on, and you are ready to recharge your batteries.
Always refer to the instruction manual. Read the charger instructions carefully; they should contain important information, including the time it takes to fully charge, the legend of the lights, and safety information specific to the batteries to use it with
Step 4. Insert each battery to be recharged into the charger according to the intended layout
This means putting the positive (+) side in contact with the positive terminals of the device, following the same principle with the negative (-) side.
Most wall chargers should have an indicator showing how to position them correctly. In general, the flat part of the battery should be placed in contact with the spring, while the one with the "protuberance" should be placed on the flat part of the charger
Step 5. Let the batteries fully charge
Many chargers have a light that changes from green to red, or vice versa, when the charge cycle is complete. Do not interrupt the procedure by disconnecting the charger or removing the batteries first, otherwise their life will be significantly reduced.
Step 6. Remove the batteries when the charging procedure is complete
Charging them too much is the first cause of shortening the life of a battery, especially with fast chargers.
- "Maintenance charging" is a technique that consists of lowering the charge to about 10% of the nominal capacity of the battery, which is usually sufficient to fully charge it without running the risk of overcharging.
- Many manufacturers do not recommend long-term use of this technique, but if you have a charger that allows you to set the charge level, keeping it at the lowest value can be an effective way to keep your batteries charged at all times.
Method 2 of 2: Recharge the Car Battery
Step 1. Remove the battery from the vehicle if necessary
Make sure the vehicle is completely off and first remove the mass terminals to prevent them from deforming, then take the battery to a well-ventilated place to recharge.
- It is possible to recharge a battery without removing it, but it is necessary to know if the ground is connected to the frame, to avoid fixing the negative in the wrong place. If it is grounded to the frame, attach the positive to the positive terminal, and the negative to the frame. If not, connect the negative terminal of the charger to the negative of the battery, and the positive to the chassis.
- If you want to know how to restart a broken down car, read this article.
Step 2. Clean the battery terminals
On most used car batteries, corrosion forms around the terminals, and it is important to clean them periodically to make sure they maintain good contact with the leads. The best way to do this is to use pure baking soda with water, and scrub the terminals with an old toothbrush to remove corrosion.
Refill each cell with distilled water, up to the level indicated by the manufacturer, if necessary. Don't overfill them. Some lead-acid batteries do not have removable ports, so, as always, refer to the manufacturer's instruction manual
Step 3. Determine the battery voltage
Typically, you should find this in your vehicle's owner's manual if it's not marked on the battery itself. If you have any doubts, you can go to any auto parts dealer and have them checked, free of charge.
Step 4. Use a charger with adequate output voltage
Depending on your vehicle and the battery it has, you will need a charger with enough power to recharge it. Typically, the batteries are 6 or 12-volt, and depending on whether the battery is a Standard, AGM, and Deep Charge model, you may need a more powerful charger.
- Some chargers are manual, so you'll need to turn them off when the battery is fully charged. Other than this and minor differences in design, all chargers work essentially the same way.
- If you have any doubts, better reiterate it, contact an auto parts dealer for a quick check. You don't have to pay for it, and you can be sure you have the right information.
Step 5. Set the correct voltage value
Knowing the voltage of your battery, you can set the charging voltage accordingly. Many chargers have digital displays and allow you to adjust the voltage to the appropriate level. Some chargers have adjustable levels, but it's always best to start with the lowest and slowest range than what you think your battery can handle.
Step 6. Attach the cables
Chargers have two terminals, one to attach to the positive terminal of the battery and one to the negative. Turn off the charger and remove the plug from the socket to be safe. Avoid shorting the terminals at any time during the process, and move away from the battery once connected.
- First, connect the positive wire, which is usually the ungrounded one.
- Then, connect an auxiliary lead or insulated battery lead that is at least half a meter long to the negative pole, and connect the negative battery lead to this lead.
- If the battery is still in the car, clip the ungrounded wire to the battery peg, and the grounded wire to a point on the car's chassis. Never hook a charger to the carburetor, fuel lines or bodywork.
Step 7. Keep the charger and battery as far away from each other as possible
Unfold the cables as much as possible, and never place the charger under the charging battery. Sometimes corrosive gases are emitted from the battery which are dangerous.
Step 8. Let the battery charge fully
Depending on the battery and charger you are using, it can take around 8-12 hours for it to be fully charged. If you are using an automatic charger, it should turn off on its own when it is fully charged. If you are using a manual one, you will need to check and make sure the battery is fully charged before turning it off.
If you want to know how to use a voltmeter to perform this step, read this article
Advice
- If you need a rechargeable battery that can last a long time, you can consider purchasing a new type called hybrid-NiMH. This type of battery combines the longevity of alkaline batteries with the recharging capacity and is useful for low-power appliances, such as remote controls and flashlights.
- Use two separate, well-marked containers to distinguish between batteries that need to be recharged and those that have already been charged. This eliminates any confusion when you need a battery at the last moment.
Warnings
- Once a rechargeable battery runs out, be sure to recycle it at a recycling center or landfill. Some types of rechargeable batteries, in particular those with nickel-cadmium and lead, contain highly toxic materials and cannot be left in a normal landfill.
- Make sure the charger is suitable for your batteries, as they are not all compatible.
- Keep non-rechargeable batteries separate to avoid mixing them together. Sometimes, putting the wrong type of battery into a charger can damage it, cause it to leak, or even cause a fire.
