Reliable Battery Chargers for All Applications

If you are looking for a battery charger that will give you reliable operation over a long period of time, you should choose a MEAN WELL battery charger.

ADM offers a broad range of MEAN WELL battery chargers, and there is a battery charger for almost every application conceivable, whether you need a simple small desk top battery charger, or a rack mount battery charger that can be fully integrated into an automated system.

In this article we look at the range of MEAN WELL battery chargers stocked by ADM and the applications that they are best suited to.

To start with it is worth mentioning at this stage that all of the battery chargers we will be mentioning are available as a 12V Battery Charger and 24V Battery Charger. However, this is not the limit of the range, as other voltages are also available.

Desk Top Battery Chargers

The MEAN WELL GC120 battery charger is ideal if you are looking for a simple desk top battery charger.

It can be used for Lead Acid (flooded, Gel & AGM) batteries. This battery charger can also be modified by MEAN WELL at the factory so that it can charge Lithium-ion batteries. A minimum order quantity does apply for this option, please contact ADM for more details.

It has a universal AC input, so is ideal if you need a battery charger that you can package up with equipment that you wish to export.

These battery chargers are also remarkably energy efficient, with a no load power consumption of <0.5 Watts.

Two Stage Charging Operation

The MEAN WELL GC120 features Two Stage Charging. At the first stage, the battery charger provides the largest current with 13.6VDC of output voltage (for 12V batteries) to charge the batteries. This is indicated by the LED indicator switching to red.

After a period of time (generally a couple of hours, depending on the capacity of batteries), the charging current will decrease gradually. After reaching 10% of its maximum value, the charger will go into the "floating charge" stage. When this happens the LED indicator will switch to green. The relationship between charging current and charging voltage for each stage of operation are shown in the curves below:

Suggested Battery Capacity

The below table sets out the battery capacities suggested by MEAN WELL for each model of the GC120. You may use a larger capacity than that shown, but this will cause the charging time to be longer.

If you have any questions about the suitable charging current for your batteries please refer to your battery supplier, or the manufacturer of the batteries.

MEAN WELL NPB Series Battery Chargers

If you need something with more power than the GC120 desktop charger, then it is worth considering the MEAN WELL NPB series battery chargers.

When it comes to the MEAN WELL NPB series of battery chargers, models can be grouped into two different categories as follows:

Basic Battery Chargers

We will discuss the Smart Battery Chargers a bit later in this article, so for now, we will concentrate on the more basic models. Unlike the MEAN WELL Smart Battery Chargers, the basic battery chargers don’t have a range of charge modes that you can select. Instead, the charge rate is set in the hardware.

These simpler battery chargers are designed to charge batteries that are not loaded. For example, a car battery or a battery in a workshop that is not connected to a load.

At the beginning stage of the charging cycle, your MEAN WELL battery charger provides the largest current with 13.8 Vdc of output voltage (for NPB-360-12*) to charge the batteries. The LED indicator will glow a solid red while this is happening.

*Other models will charge at a different voltage, refer to data sheets for details.

After some time (typically a couple of hours, depending on the capacity of batteries), the charging current will decrease gradually. When the battery charger reaches 10% of its rated output, it will go into the "floating-charge" stage. The LED indicator will glow solid green during this stage.

The NPB-360 models have a built-in cooling fan. This will spin during the beginning stage of the charging cycle, but slow down during the ‘floating charge’ stage.

The relationship between charging current and charging voltage for each stage of operation is shown in the curves below:

The MEAN WELL NPB-120/240/360 are available as a 12V Battery Charger and 24V Battery Charger. 48V models are also available.

Each of the data sheets gives you the suggested battery capacity for each of the models.

MEAN WELL recommends that you select batteries, which fall within the recommended range. Although you can use batteries with a higher capacity, this will extend the charging time.

Best Battery Charger for Caravans

It is not uncommon for batteries in caravans, or boats to be under load when being charged.

If you are charging lead acid batteries under these conditions, then you need to use the MEAN WELL NPB-450-12 battery charger.

The key feature of the NPB-450-12 over the standard NPB-360 is its ability to be able to safely charge batteries that are under load, prolonging their life span.

This makes the NPB-450-12 the best battery charger for use in caravans, motor homes, and any other application where you may want to charge a battery that is under load.

It is suitable for charging lead acid, AGM, Gel type batteries and lithium-ion batteries.

To ensure the reliable operation of the battery charger the following protections have been incorporated into its design:

• Short circuit protection
• Reverse polarity protection
• Over-voltage protection
• Over temperature protection

Smart Battery Chargers

When you need a more ‘heavy duty’ style battery charger, you may wish to consider one of the MEAN WELL NPB Series smart battery chargers.

The MEAN WELL NPB-450 Series up to the NPB-1700 has additional features over other battery chargers in the MEAN WELL range, making them perfect for larger and hence more expensive batteries. Smart chargers have additional settings and options to help prolong battery life. 

The NPB-450/750/1200/1700 will ‘detect’ the voltage of the battery they are connected to and will not start to charge if the battery is connected backwards or is the wrong voltage. This means you won’t accidentally start to charge a 12V battery with a 24V battery charger.

The MEAN WELL NPB-450/750/1200/1700 battery chargers also have three modes of charging, which are selectable by a switch.

The first mode is two-stage charging. In this mode, the battery charger will charge the battery at a constant current until the voltage across the battery reaches the voltage shown below:

At this point, your MEAN WELL battery charger will change to constant voltage mode until the charge current drops to around 10% of the rated output. This ensures a rapid charge without distressing the battery. When the charging current drops to 10%, the battery charger stops charging and the charge light changes to solid green, indicating a fully charged battery.

In the three-stage mode, the MEAN WELL battery charger will go through the same process, but when it has finished charging, it keeps charging in "float" charge mode at 13.8V (or 27.6V or 55.2V) indefinitely or until the power is turned off.

This is the mode to use for house batteries in caravans because it keeps the batteries topped up without overcharging them. If the power is turned off and back on again, the charger starts the cycle again - boost then float.

The MEAN WELL NPB-450/750/1200/1700 smart battery chargers also have a temperature sensor, which can be used to detect heat rise in a battery being charged and limit the charge rate to prevent overheating. Typically, this would be used for batteries in an enclosure that may prevent heat from escaping.\

The MEAN WELL NPB-1700 can charge two banks of batteries. However, it will only charge the second bank if the first bank has finished charging. This is only possible if the charger is used in two stages.

In three-stage mode, the charger continuously charges the battery so it never finishes charging the first battery bank. Therefore it will not switch over and charge a second bank of batteries.

When selecting which battery charger to use, it is important to note that the size of the charger must suit the size of the batteries. The MEAN WELL data sheets list a range of battery sizes that each charger is suitable for.

If you choose a battery charger that is too small for the battery, it will take longer to charge and may never reach full charge. If you choose a charger that is too big, the battery may be forced to a higher voltage than normal and this can cause the charger to stop charging earlier than usual which will mean the battery is not fully charged.

Battery Chargers with CANBus Interface

Some applications, such as mobility scooters require a battery charger that can recognise which model of battery has been installed and automatically switch to the corresponding charging curves.

MEAN WELL has made this possible by giving you the option of having a CANBus interface incorporated into either the NPB450/750/1200/1700 series battery chargers. CANBus is one of the most common interface protocols used on vehicles and mobile equipment.

Through this CANBus interface, you have the ability to set the required charging curve and monitor the charging status of batteries, which gives you an intelligent battery charging system. The parameters you can determine to set the charging curve include pre-charge voltage values, pre-charge current values, state-changing points, constant current values, constant voltage values, floating charge voltage values, charge cut-off, and the timing of all the above charging settings.

MEAN WELL also incorporates a built-in monitoring function that can determine the model number of the battery, capacity, charging status, internal temperature, and protection status. It also monitors the charger's present charging condition, voltage values and current values.

The MEAN WELL CAN Bus NPB-450/750/1200/1700 chargers are ideal for when you want to closely monitor the battery charging status. They enable batteries to be quickly and efficiently fully recharged under safe conditions.

Programmable Battery Chargers

With industrial battery charging applications becoming increasingly technical and highly complex, there is an ever growing need to vary the charge curve as part of an intelligent integrated battery backup system.

Last year MEAN WELL introduced two new programmable battery chargers to their line-up.

The key difference between these new battery chargers is the fact that one model is rack mountable. The below table outlines the key features of both models.

The rack for the RCB-1600 is ordered separately under part # RHP-1U and takes up to 5 battery chargers.

Both models have a built-in active current-sharing feature, meaning that the outputs of the battery chargers can be connected in parallel.

The built-in default 3-stage charging curve, which is shown in the below diagram can be programmed to suit your own particular application, by using the built-in I2C interface (PMBus protocol).

Alternatively, you can choose to select one of the predefined charging curves shown in the below table:

The RCB-1600 has the added advantage of enabling you to simply control the voltage and current output levels by applying an external DC voltage or regular resistance. No special complex additional circuitry is required.

Over the past 30 years MEAN WELL has built a global reputation for highly cost effective reliability. The product data sheets detail the MTBF (meantime between failure data). MEAN WELL adhere to a globally recognised standard to calculate MTBF data, namely MIL-HDBK-217F.

These new programmable battery chargers are backed by a 5 year warranty.

As you can see, the battery chargers offered by ADM can be used in a very wide range of applications. From simple desk top battery charging, right through to battery chargers that can be integrated into automated systems.

If you would like help in determining which battery charger is best suited to your own particular application, then please do not hesitate to contact ADM. A member of our expert team will gladly answer any questions that you may have.

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