You will need to know a few things to get it right when choosing a good battery charger but get the basics right and you are on your way to having a battery charger that you can rely on. If you choose to dismiss these basics, it may prove disastrous for you and the charger you pick might cause harm to the batteries, your property, yourself and perhaps your family.
Battery Charger Basics
What do you look for in a good battery charger? What does it take for it to be the right charger for your batteries? Once we get through these basics, you will get a better understanding of battery chargers and the options available for you to make the right choice.
Charge Methods - state of the art chargers in the market today are very smart, they use a combination of charging methods to efficiently and safely charge those batteries. Let’s take a look at the three charging methods used in these smart chargers.
- Constant Current Charging or CC Charging - in this method an application of a constant current puts juice back into the battery. It is far from perfect since it needs to be closely monitored to prevent overcharging which frequently happens and also the batteries almost never get a full charge because of that fine line between overcharge and a full charge - to keep the batteries safe from ruin they are often taken out before they are full.
- Constant Voltage Charging or CV Charging - this method builds up the voltage of the battery with a constant stream of DC voltage that is applied to the battery. The battery voltage and the charger voltage do not change and adjust. Thus, the chance of a heavily drained battery to get a large jolt of voltage is common and this results in damage to the battery and shortens the life of said battery.
- Trickle Current or TC Charging - this method is used as an initial charging method so that the battery is not hit with a large amount of current. The battery is fed a small amount of current so that damage can be prevented.
Smart battery chargers use these three charging methods to quickly and safely put back the charge for your batteries. An initial TC charge is fed and after a while the CV charge kicks in and the CV charge comes into play and applies a constant voltage with a diminishing current when the battery is almost fully charged and this fills up the tank to full without any damage.
Charger Specifications - The right charger for the right battery, right? But, it is not as straightforward as this. One must consider battery compatibility, charging current, cut-off or termination voltage and cut-off current.
- Battery Compatibility - there are many types of rechargeable batteries; Lithium-ion (Liion), Lithium-ion-phosphate or lithium-phosphate (LiFePO4), Nickel-metal-hydride (NiMH), Nickel-cadmium (NiCd), Lithium-ion-cobalt or lithium-cobalt (LiCoO2), Lithium-ion-manganese or lithium-manganese (LiMn2O4) and the old Lead Acid. Each of these have different chemistries that may or may not be compatible depending on the charger.
- Charging Current - the current delivered may be different for a variety of chargers and there are also ones that are capable of multiple charging currents. Smaller capacity batteries usually require less current to prevent them from getting damaged and high capacity batteries need copious amounts of current to fill them up to make the charging faster.
- Cut-off or Termination Voltage - this is the level set on the charger at which it stops charging. The cut-off voltage specified for a typical professional-level charger is set at a range of +/- 0.05V.
- Cut-off Current - this is the level of current set on the charger at which it stops feeding current at the CV charging stage. More than protection for the batteries getting overcharged, it also plays a part in its efficiency.
- Charger Performance - most important of these revolve around two aspects and those two are safety and convenience.
- Safety - there are four things to look for when it comes to this performance aspect:
- Heat dissipation - protects the charger unit from damage caused by heat during charging.
- Fireproofing and heat-resistance - high quality chargers use fireproof not fire resistant materials.
- Reverse polarity and short circuit protection - avoid accidents and damage for you and the batteries, even when you insert the batteries wrong.
- AC-DC power adaptor - low and safe DC voltage for the charger.
- Convenience - of course why have it the hard way when you can have it easy.
- Intelligent charging features
- Independent charging channels
- USB output function
- Clearly visible and easily understood indicators
- Charger with Advanced Technology - cutting edge features that very few in the market have that is just icing on the cake for a charger.
- 0V Activation - safely charge over-discharged batteries by applying an extremely low starting charge current.
- Soft Start - applies a slowly rising charge current as a way to protect from jolts of large current and prevent damage.
- Memory Effect Deep-discharge - memory effect is also called battery effect, lazy battery effect or battery memory which causes batteries like nickel cadmium and nickel-metal hydride rechargeable batteries to hold less charge as a result of repeated recharging while only partially discharged. The charger sets up a battery for some deep-discharge cycles as a way of reconditioning them back to their original capacity.
- Automatic Stop Charging - the charger detects that the battery is full so it stops charging.
- Automatic Restart Charging - some charger units can also restart the charging process again when it has detected that the battery in the charging bay has dropped from a full charge and gets it back to full.
Having discussed the various aspects pertaining to what makes a good battery charger; you are now better equipped to make that choice. It is not clear cut and it will require some careful thinking on your part to pick the best one and the right one for you. At least now you have the knowledge to filter the numerous chargers in the market and select the right one or right ones for you.
If you have any further questions, feel free to contact us.