Car batteries die because of parasitic drains. Basically, any electrical device that connects to the battery will consume small amounts of charge until your battery is empty. That doesn’t even account for the threat of self-discharge. But how can a battery tender help you?
Can A Battery Tender Charge A Dead Battery? A battery tender can charge a dead battery. But you need at least 2 volts in the battery. The tender can use small volumes of electricity to bring the battery back to life, but not if it has 0 volts. One solution involves connecting two batteries, one good and the other dead, in a parallel circuit.
You can use a battery charger if you don’t have the battery tender. Battery chargers will recharge dead batteries. But you’re still better off sticking with a battery tender where maintenance is concerned.
A battery tender will check the functionality of the battery before entering bulk charge mode. This is where it delivers its full charge to the battery until its voltage rises to a predetermined level.
The final stage is called the maintenance charge mode. This is where the battery tender keeps topping off the battery. According to the Battery tender, their device is better than a trickle charger because it has a brain. It includes a microprocessor that controls the battery tender’s sophisticated functions.
The battery tender is a battery maintainer. It differs from a battery charger, which uses large volumes of current to charge a battery quickly. The maintainer maintains a consistent charge in the battery by pouring small amounts of current into the battery over an extended duration.
This extends the battery life by keeping it charged at all times. Apply battery tenders to cars that don’t get much use. The battery tender will keep the battery from losing power.
Make sure you select a battery tender type that fits your situation. Some maintainers will only accommodate specific battery types, such as lead-acid and lithium-ion. You may kill a battery by pairing it with the wrong maintainer.
Was the tender even designed with cars in mind, or is it better suited to household batteries? You must answer these questions and more before proceeding.
How Do You Charge A Completely Dead Car Battery With Battery Tender?
- Turn the car off, open the hood and remove the black and red terminals from the battery using an adjustable wrench.
- Attach the tender’s red clamp to the battery’s positive terminal. Make sure the clamp is secure, and only a deliberate physical effort can remove it.
- Connect the black clamp to the engine block. Because the battery has a connection to the vehicle’s frame, you can run the black clamp from the tender to the frame if it is more convenient than the engine block.
- Change the settings (2 to 6) before connecting the tender to a power source, such as a wall outlet.
- Leave the battery tender to charge the battery. The light will remain red to signify the charging process.
- The light will turn green once the tender charges the battery to completion.
- Don’t touch the clamps. Start by disconnecting the battery tender from the power source. And then, you can pull the clamps off the battery terminal and engine block.
- Use a wrench to reconnect the terminals. Secure the connections tightly before closing the hood and starting the car.
Charging a dead battery is that quick and easy. Although, complications may arise. Keep the following in mind:
1). Don’t proceed without checking the manual. What does it say about charging a dead battery? The battery tender’s efficacy may depend on the model. Take this Battery tender guide as an example. It warns consumers against using a battery tender junior charger to charge a battery with less than 3 volts.
Apparently, the internal safety circuit won’t permit the charger to deliver the voltage the battery needs until it detects three volts or more. A flashing red light will let you know that the battery tender junior charger has refused to accommodate the needs of the dead battery.
2). You can overcome the issue above by connecting the dead battery to a 9V battery. This will fool the battery tender into thinking that the dead battery has sufficient voltage. But you must maintain a connection between the batteries for the battery tender’s charging cycle to persist, at least at the start.
3). Sometimes, the battery tender fails because you connected it to a power strip or extension cord instead of a wall outlet.
4). Inspect the fuse of a battery tender that refuses to charge the battery. You should also look for loose connections.
5). If you connected the tender to the battery several hours ago, maybe even a day or two ago, and it still isn’t charged, test the battery. It might be defective, especially if you haven’t used the battery for years.
6). You must take deliberate steps to revive a dead battery. Don’t expect the battery tender to perform this task automatically. You need to connect the battery tender to the battery manually.
How Do I Know If My Battery Tender Is Charging?
The battery tender has LEDs that tell you everything you need to know about the operations of the device. For instance:
- The red light will flash temporarily to let you know that the device has access to a reliable power source. The flashing light should subside after a while. If it doesn’t, either the battery is dead, or the voltage is too low. The battery tender may refuse to charge a battery whose voltage is less than 3 volts. Don’t start panicking until you check the alligator clips and ring terminals. A loose connection can also trigger flashing red lights.
- A solid red LED appears when you connect a healthy battery, and the charging process begins.
- You will notice a flashing green light and even a red LED once the battery’s charge exceeds 80 percent. Even though the battery is ready for use at this point, you should leave it alone until it attains a full charge.
- You will see a solid green LED when the battery is fully charged. You can disconnect the battery at this point. You can check my article on these LEDs to know in greater detail.
It is worth noting that flashing LEDs do not guarantee that a battery is charging. A defective battery can refuse to accept the charge even though the battery tender’s lights are blinking.
How Long Does It Take A Battery Tender To Charge A Completely Dead Battery?
It can take eight hours or less to charge a dead battery. But that is not a guarantee. The deciding factors include the type of battery tender and the health of the battery.