Car Batteries

What Are The Different Types Of Battery Chargers?

Mike Cross
Updated Jan 21, 2021
What Are The Different Types Of Charging

When it comes to charging something, mainly a battery, there are a variety of type/method that can be used. Each type has its positives and negatives. In this article, we will discuss the common basic types of battery chargers.

Read on to learn the different charging types that are possible as well as what sets them apart. We will give details so you understand what is going on with each type and also when or why you might want to use a particular type.

What Are The Different Types Of Charging
What Are The Different Types Of Charging?

Types Of Charging

Before going into deep detail, we will list out the nine basic charging types. Each one has a purpose, and if you want to learn about a particular one, then you can jump straight to it. The main charging types are:

  • Constant Voltage
  • Constant Current
  • Taper Current
  • Pulse Charge
  • Burp Charging
  • IUI Charging
  • Trickle Charge
  • Float Charge
  • Random Charge

Constant Voltage

The first type of charging a battery we will look at is a constant voltage. A constant voltage does what the name implies and provides a constant voltage to the battery.

These types of chargers are generally cheap and simple. In the simplest form, a constant voltage charger can be a DC (direct current) power supply with a step-down transformer that rectifies the power.

You can use this type of charger for both lead-acid cells as well as lithium-ion cells. However, the lithium-ion charger is normally a bit more advanced for the safety of you and the battery. The reason why these are good is that they are cost-effective, but there are better options.

Constant Current

The next type of charging is a constant current. This is similar to constant voltage because it keeps one aspect of the charging constant, but this time it is the current or flow of electricity thru the battery at the constant.

The way it does this is that it changes the voltage, so the current coming out is always equal. When the battery gets fully charged it is able to stop charging.

Most of the time this type of charging is used for nickel-metal hybrid cells and nickel-cadmium batteries. The reason this type of charger is good is that it stops charging when the battery is full, but other types can also do this and work better for certain types of batteries.

Taper Current

The next type of charging is taper current. This type can damage batteries very easily. You can get away with it with some SLA batteries, but it is a good idea to keep an eye on the charging of your battery.

This is because the taper current does not provide a constant voltage. It is a crude type that sends in a voltage that causes the current to diminish as the cell voltage builds up.

The voltage going into the battery is unregulated. This charging should not be used except for the last resort because there are better and safer options.

Pulse Charge

The next type is a very good type to help extend your battery life, and that is pulse charging. As the name suggests, the energy goes into the battery in pulses.

The current goes in as a pulse, and you can set how long of pulse period you want. Normally it is around 1 second. Then, you have 20 milliseconds to 30 milliseconds of rest between pulses.

This resting period allows the battery to stabilize. By stabilizing it means that the battery is able to equalize the reaction across most of the electrodes before the next charge pulse comes in.

By being allowed to stabilize it allows the chemical reaction to keep pace with the incoming charge. This prevents unwanted chemical reactions at the electrode surface such as gas being formed.

It also prevents the formation of crystals and passivation. This type is good for any battery.

Burp Charging

The next type of charging is burp charging which expands on pulse charging. It is just like pulse charging, but with an added step. Before the next pulse goes in, with burp charging it sends a discharge pulse in.

This depolarizes the cells and helps to eliminate any gas bubbles that have built up. The releasing of the gas bubbles is known as burping. Other names for this type of charging are reflex or negative pulse charging.

This type of charging is supposed to extend battery life more and allow for faster charging, but there is no conclusive evidence of this. The only evidence is that burp charging can’t hurt a battery, so it doesn’t hurt to try it if you are a fan of pulse charging.

IUI Charging

The next kind of charging is a newer type for lead-acid batteries, and that is IUI charging. This type is not for all lead-acid batteries, so you want to make sure yours is compatible.

IUI charging is done in stages, and the first stage is bulk charging where it is charged at a constant rate until it reaches a preset point where gases start to form.

When it reaches this point the charger switches into a middle phase that provides a constant voltage and the current drawn by the battery will slowly drop until it reaches a particular point and the current drops at a diminishing rate.

Once it reaches this second preset point the battery switches back to a constant current mode and charges the battery to a higher preset point until it reaches that and then the charger shuts off completely.

This final charge helps stabilize the battery and makes sure that the cells are equally charged ensuring longer battery life.

Trickle Charge

The next type, trickle charging, is designed for battery maintenance. This type is not for bringing a battery back from being dead but is instead designed to keep a battery that is not in use charged.

With trickle charging a small current is applied to the battery at the rate that the battery is discharging. This keeps it charged and ready to go and helps keep chemicals from building up on the inside of the battery hurting its life.

Some charges automatically switch to a trickle charge mode when a battery is fully charged. You can’t use this charging on all batteries though. You shouldn’t use it on NiMH or lithium because they are easily overcharged.

best battery tender
A battery tender

Float Charge

The next type is similar to trickle charge in that it does not overcharge the battery. Float charging is mainly used on lead-acid batteries, and it holds the voltage of the battery at a point that is below the maximum charge.

It is for emergencies mainly and is good for battery backup. The way it works is the battery and load are permanently connected in parallel across the DC charging source.

Random Charge

The last type is a random charge. This is when a random charge is applied to something. This is because the power is coming from a source that can’t be controlled completely.

For example, the alternator works based on how fast the engine is going, so it provides a different charge at different times. Another instance is solar power where the sun is at different levels at different times.

The random charge is pretty common but generally isn’t used for charging batteries in most cases.


So, now you know all the basic types for charging a battery. You know the nine common battery charging types and how they work.

You also now know the benefits and negatives of each one. Whenever you need to charge a battery, you should be able to pick out the best battery charging type for your needs.

Mike Cross
Life is too short to drive with stock audio

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