Battery Charger vs. Maintainer: Understanding The Difference

When considering buying a battery charger, you’ve probably heard the terms battery maintainer and battery charger and aren’t quite sure of the difference.

The article below will discuss the difference between the battery charger vs. maintainer to help you make a more informed decision.

Trickle Charger Basics

Below is the general knowledge you should know about the trickle charger.

What is a Trickle Charger?

Trickle chargers never stop sending low emissions of current to the battery.

The charger will send an electric current even if your battery is fully charged. If you own a lithium-ion battery, there are no risks to your battery.

However, if you have a lead-acid battery like those in boats, motorcycles, and cars, the constant transmission of electric current to the battery could damage the battery.

Furthermore, cheaper model chargers could even damage the battery entirely over one night if left connected once the battery hits 100%. 

Why Can a Trickle Charger Be Dangerous?

Simply explaining what goes on as a battery charges will outline the risks of using a charger that constantly charges the battery (trickle charger) even after it fully charges.

The battery receives electric current from the charger, which passes through the negative and positive terminals by the plates and through the battery acid (electrolyte solution).

As the electricity passesough the solution a r,eaction occuchanges a chemical structure, and potential energy is stored.

When a battery is low on charge, it can receive higher amps of power and readily convert the electrical energy into potential chemical energy, which can be released as electricity if a circuit is completed.

As your battery approaches full charge, it can’t accept the same amps of current as before because it is running out of room to store it.

Feeding excess electricity will result in the battery converting as much as it can into stored energy.

However, the rest has to go somewhere.

The excess electricity causes hydrolysis, meaning as the excess electricity passes through the electrolyte solution, it breaks down and evaporates the oxygen and hydrogen molecules, causing the battery to overheat.

Also, electricity pumped into the battery that can no longer be stored will break down the water molecules in the battery acid.

If this occurs for prolonged periods, the acid level will drop due to evaporation, causing the plates to undergo sulfation which causes extreme damage.

Plus, the chemistry of the battery changes for the worse.

Therefore, leaving your battery hooked up to a trickle for days or weeks on end will destroy your battery. 

Can I Use a Trickle Charger Safely?

Yes, it is possible to safely use your trickle charger; all you have to remember is to unplug the charger once your battery is fully charged. All batteries lose their charge over time.

However, proper care of your battery will slow down the process. 

To properly care for your battery, it’s best to hook it up to a trickle charger once every month for only a few hours.

Once it’s fully charged, unplug it from the charger and give it some time to rest for a couple of weeks.

Battery Maintainer Basics

Below is the general knowledge you should know about the battery maintainer.

What Is a Battery Maintainer?

Battery tenders are similar to battery maintenance and float chargers, providing a constant power supply to the battery terminals.

The only difference is that battery tenders are processor-controlled, meaning they can refrain from charging defective batteries, use easy-to-understand color indicators, and use spark-free technology to enhance safety.

Why Should You Use a Battery Maintainer?

The two main reasons for using a battery tender are as follows.

1. To Prevent Sulfation

It will lose its charge if you’re forced to keep your automotive stored away for some time.

All lead acid batteries self-discharge over time.

As the battery continues self-discharging over time, sulfation builds up within the internal plates resulting in loss of capacity and cranking amps.

Therefore, using a battery tender ensures your battery is constantly charged to prevent sulfation.

2. To Prevent Parasitic Drains

With vehicles becoming more integrated with technology (diagnostics, GPS, and alarm systems), these features draw small amounts of power from the battery when the ignition is off.

If leftover time, this could kill the battery.

Using a battery will always ensure your battery is fully charged to avoid you dealing with the problem of a dead battery.

Can I Use a Battery Maintainer Safely?

With battery maintainers, you have a variety to choose from.

The basic battery tender functions by plugging straight into your typical household socket.

Similar to when the jump starts, you can remove the battery and connect the two terminals.

However, you don’t have to remove the battery if your outlet isn’t too far from the car.

Some battery tenders require you to turn them on, while with others, the battery will automatically start charging when plugged in.

However, the battery doesn’t continue once the battery hits 100% and resumes charging once there is a drop in charge. 

How To Hook Up a Battery Maintainer: Step by Step

  1. Turn off your vehicle and clear the space of any hazards.
  2. Use a wrench to remove the battery’s positive and negative terminal wire connectors.
  3. Plug the battery charger into an outlet and turn it on.
  4. Attach the positive and negative battery clamps to their respective positive and negative battery terminals. Never attach the clamps to the vehicle frame, engine block, or moving engine parts.
  5. Once the charger indicates the battery is fully charged, the battery stops charging and only resumes charging once the charge drops.
  6. Finally, unplug the battery charger and reattach the positive and negative connector wires. 

Here are the steps for Charging the Battery While it is in the Vehicle

  1. Take all the necessary precautions, such as clothing, eye protection, and nearby assistance in emergencies.
  2. Place the charger as far as the cables allow from the battery.
  3. Before turning on the charger or plugging in the AC adapter, ensure the charger’s DC cord and AC cords are not in contact with any moving parts (hood, doors, or fan blades).
  4. Connect the charger clips respective to the battery terminals. For a positive grounded vehicle, connect the black (negative) charger clip to the negative post of the battery and the red (positive) clip to the vehicle engine block away from the battery or vehicle chassis. However, with a negative grounded vehicle connect the red (positive) charger clip to the positive battery terminal and connect the black (negative) charger clip to the vehicle chassis or the engine block away from the battery. Avoid the carburetor or fuel lines.
  5. Once everything is in place you can turn on the charger to begin charging the battery. A battery has to produce more than three volts to start charging. Therefore, if your battery has less than three volts it automatically won’t charge. Also, if a 12V lead acid battery isn’t charging and produces a voltage output lower than 9V it’s likely defective and needs replacing.
  6. Keep an eye on the light indicators for further information regarding the state of the battery. Prolonged red flashing indicates the clips might have been incorrectly placed or the battery is producing lower than three volts. A steady red light indicates the battery is charging. A flashing green light indicates the battery has surpassed 80% charge. A steady green light indicates the battery is fully charged.

Trickle Charger vs. Float Charger (Maintainer)

The key difference between a float charger and a trickle charger is that a float charger stops charging the battery once it hits 100% to prevent overcharging.

Trickle ChargerFloat Charger
Charges the battery to 100%Charges the battery to 100%
Overcharges the battery after it reaches 100%Charging stops once the battery is at 100% and resumes after the battery self discharges and can receive current
Kills a battery if left hooked up for prolonged periodsCan be used indefinitely

A Battery Tender Buying Guide

When selecting the battery tender to buy there are a number of factors to consider.

1. Amperage Selection

Amperage refers to the flow rate of electricity into your battery. Battery tenders have different amperages to choose from.

You can choose to get the automated amperage or set amperage that allows you to choose the amount of amperage to set allowing you to charge your battery faster.

However, if the purpose of your battery is to maintain a battery’s power it’s best to opt for the automatic amperage.

If you’re a beginner it’s best to avoid messing with the settings.

2. Safety Features

When dealing with electricity safety is an important factor.

Therefore you want to choose a battery tender that ensures your safety.

Below are some of the safety features to consider.

  • Quick connect – the best tender comes with a quick connect pigtail that you connect to the battery terminal allowing you easily unplug your battery.
  • Reverse polarity protection – in case you don’t have a pigtail and use clamps instead this feature prevents damage to the battery in case you wrongly attach the clamps to the wrong terminals.
  • Automatic voltage and amperage regulation – it ensures the battery isn’t overcharged to the point of damaging it.
  • Spark-resistant clamps – when directly connecting to the battery terminals, your clamps should hold down the sparks to a dull roar.
  • Short circuit protection

3. Other Factors to Consider

A couple of other factors to consider when buying a battery maintainer include:

  • Lightweight plastic design
  • Visual indicator lights
  • Battery tester onboard
  • Constant charging
  • Charge time
  • Compatibility with your battery
Motorcycle Battery Charger

Caption: Motorcycle Battery Charger


Having discussed the trickle charger and battery tender, you can now make a more informed decision on the charger you want.

If you have any inquiries about battery cables, feel free to contact Cloom Tech.