How To Choose A Car Battery Charger
What is a car battery charger? It charges car batteries right? How complicated can it be? Believe it or not, there are literally hundreds of models of chargers to fill every situation. What’s your situation? Your particular situation will determine how you will choose a battery charger for your car.
Battery Charger or Jump Starter?
The first question to ask is if you actually need a battery charger at all or are just looking for an emergency jump starter to carry in your car. Battery chargers typically stay at home or shop and are plugged into household current in order to charge a battery and in many cases maintain its charge as well. Jump Starters are really batteries that you can carry with you in your car and in an emergency use to jump start your low car battery. If you’re looking for a jump starter, this article is not for you. I will have another article on how to choose a jump starter.
Battery Size and Voltage:
Next you need to ask yourself, in what vehicle will the battery be used; a car, boat, light truck, garden tractor, classic car, etc? The vehicle will determine whether the device will need to charge a large Baterias de Auto a Domicilio Viña del Mar or a small one and if it needs to handle only 12 Volts or will need to also handle 6 Volt applications. Common inexpensive car battery chargers for home use typically handle 12 Volts and in some cases will handle 6 Volts as well. If you don’t have a need for 6 Volts (some classic cars and some tractor batteries), and don’t think you ever will, then you can save money if you choose a 12 Volt charger. These days, some of the best home chargers are still relatively inexpensive and will handle both 6 and 12 Volt applications.
And you thought you left chemistry behind at school… I promise I will make it simple! Most all car batteries are lead-acid batteries with lead plates in an acid bath. Where they differ in chemistry is whether they are standard lead-acid, AGM, Gel Cel, or Deep Cycle. You don’t need to know what those chemistries mean, you just need to know which type they are. Not all chargers are designed to handle the special needs of AGM, Gel Cel or Deep Cycle types. Most are standard lead-acid. The specialty chemistries can be found in applications designed for other equipment besides cars.
Battery chargers can be manual or automatic charging. Many are fully automatic which means they can detect when it is fully charged and automatically switch to a trickle charge or float mode to protect it from overcharging. This is an important feature that is available on many better quality home chargers.
There are many safety features available on modern car battery chargers and the more you have the better. Some safety features to look for include:
1) Reverse Polarity Warning – A charger can warn you if you have the wrong cable hooked up to the wrong post. Usually this will cause sparking which could ignite gas around the battery and cause an explosion.
2) Float Mode – A fully automatic charger will have a trickle charge or float mode which detects when it is fully charged and backs off the charging amps so as not to harm the battery from overcharging. In some cases severe overcharging can cause overheating, damage or even explosions.
3) Spark Proof Clamps – No matter how careful you are sparking is still possible when connecting the charger clamps. Some devices have this safety feature that reduces or even prevents sparking at the connection.
4) Battery Tester – Many chargers can detect the health of your battery. Over time they can build up sulfate on their plates reducing their ability to accept a full charge. Some devices can detect that it is unable to accept a full charge and alert you to the problem.
5) Battery Tending/Maintenance – Many chargers are capable of providing maintenance or tending for your battery while connected. This is especially useful for those which are only used rarely or are in storage for part of the time like garden tractors, motorcycles, boats, RVs, etc.
6) Clamp Amps – Clamps that connect to the posts have an amp rating. Usually that rating is 50 amps or more. It should not be less.
Other Desirable Features:
1) Microprocessor Control – Basically a microprocessor is a computer on a chip that can direct the entire charging process based on feedback from the charger and the battery itself. Many modern chargers are microprocessor controlled and those that are have more options for conditioning or recovering batteries and have much finer control over the charging process even improving charging performance.
2) Multi-Step Charging – Some chargers have the capability to charge in multiple steps which gives them the flexibility to more finely control the charging process. Steps can range from just charging and float modes to as many as 7 steps as provided by, for example, Genius Chargers:
Step 1: Diagnostics
Checks the voltage to make sure connections are good and the battery is in a stable condition before beginning the charge process.
Step 2: Recovery
Initializes the Recovery process, if needed, for deeply discharged or sulfated (desulfation) batteries by pulsing small amounts of current.
Step 3: Soft Start
Begins Bulk charging process with a gentle (soft) charge.
Step 4: Bulk
The Bulk charging process continues and returns 80% of the battery capacity. Indicated by the 25%, 50% and 75% CHARGE LEDs.
Step 5: Absorption
Brings the charge level to 90%. The charger will deliver small amounts of current to provide a safe, efficient charge and limit gassing.
Step 6: Trickle
The battery is fully charged and ready to use. In this step, the charger will only deliver enough current as it is required. If more current is needed, the charger will switch to Maintenance.
Step 7: Maintenance
Continuously monitors the voltage to determine if a maintenance charge should be initiated. If the terminal voltage falls below a specific value, the charger will start the Maintenance cycle until voltage reaches the proper value and then discontinues the charge cycle. The cycle between Trickle and Maintenance is repeated indefinitely to keep a full charge, without overcharging. The charger can be left connected indefinitely.
3) Multiple or Appropriate Charging Amp Rates: Many chargers will either have multiple charging amp rates depending on whether you are charging a small battery, a large one, or you are maintaining or tending one. It’s common to see at least 2 amp and 10 amp charging rates if not a medium 4-6 amp rate as well. It’s not critical to have large charging amp rates unless charging time is important to you. A microprocessor controlled battery charger with a lower amp rate will charge more slowly but, if the time is not unacceptable, will do the job. Check the battery charger to make sure it matches your application as far as charge time and charging amp rate.