Cameras, remote controls, watches, toys, flashlights, recorders… a simple look around the house brings us back to the reality that there are many devices that require batteries to work, an advantage over batteries because we can easily replace them but also with the inconvenience of having to buy them periodically. Halfway between one thing and another are rechargeable batteries , more expensive than traditional ones – especially if we take into account that a charger is required – but more sustainable thanks to their longer lifespan.
And it is that having them ready to be used means simply inserting them into the charger and connecting to the power. Now, does it matter one charger than another? What should we take into account when buying a battery charger? Here is a series of buying tips.
Table of Contents
What to take into account when buying a rechargeable battery charger?
A recommended option from a compatibility and cost point of view is to buy a charger and batteries at the same time . However, it does not have to be the case. The type of battery charger that best suits your needs will depend on how many batteries you have to charge, how often and how quickly you need them. Depending on these parameters, the investment will vary considerably.
A look at the battery: chemical components
From an initial investment point of view, rechargeable batteries are more expensive than disposable ones , but being reusable they are more environmentally sustainable and last longer.
Rechargeable batteries are made with chemical elements such as Nickel – Cadmium (NiCd), Lithium – Cadmium (LiCd), Nickel-Metal Hydride (NiMH), Lithium ions (Li-ion) and finally lithium ion polymer.
Taking into account the memory effect of Ni-Cd batteries – which reduce their useful life when charged when they are not completely empty – and how polluting cadmium is, the first two types of batteries have given way to those that are only lithium or NiMH, which also have no memory effect , so their charging cycles are higher. In our selection of featured models you will only find compatible chargers for batteries of this type.
batteries
Battery size and quantity
In the market we can find chargers that range from 2 units to 8 capacity, although the vast majority are 4. In any case, more important than the number is knowing if the charger is capable of individually charging each slot – or what it is the same, that you can charge only one battery even if the device has capacity for 4 – or if you have to do it in pairs.
Battery chargers are generally compatible with AA and AAA type batteries, as is the case with the models listed below. If you need to charge special 9V batteries or devices such as tablets and mobile phones, there are also models with a USB port for this purpose .
smart chargers
The chargers that best monitor the state of battery life are smart chargers – also known as delta-V -, which monitor the voltage of each battery and stop charging when the charge is complete. In this way, heating, overloading or the batteries not reaching 100% of their capacity are avoided.
There are other types of chargers that, without being considered intelligent, keep the batteries always charged since they foresee that they discharge naturally when they are not used, estimating how much energy they have lost and replenishing it with small charges. However, they do so as a guide, without taking into account the age or condition of the battery. This method doesn’t prevent overloading, but it does at least ensure that they’re in an optimal state when you want to use them.
The most basic charging option provides constant power until you unplug it. In this case, you run the risk of removing them without fully charging them, reducing the autonomy of the device to which you embed them. On the contrary, if the loads of more reduce their useful life and they overheat. These types of chargers are the cheapest but the useful life of the rechargeable batteries will be much shorter.
charge indicators
While the simplest chargers have a light to indicate whether the batteries are full or not, the most advanced ones have digital screens to show the state of charge and other parameters such as the estimated time. Straddling each other is a chromatic indicator that signals the progress of the load by changing colour.
upload speed
The faster a battery charger charges, the more expensive it is . Foresighted users often anticipate their charging needs and leave batteries charging overnight, so a trickle charger would be more than enough. Also, some chargers that are designed to be left on overnight and turn off after that period of time.
However, there are chargers capable of completing a charge cycle in just a couple of hours and there are even chargers on the market capable of 100% charging a set of batteries in 15 minutes, according to the manufacturer.
However, the capacity of the battery – which is measured in mAh like mobile phone batteries – must also be taken into account: those with more capacity will obviously require more charging time, but will also provide greater autonomy. These batteries with higher amperage are especially indicated for devices that consume a lot of electricity, such as flashes.
Security
The most complete battery chargers include protections against electrical accidents that protect the integrity of the charger itself and the batteries , prolonging their useful life. Safety features include timers, temperature control, overvoltage and short circuit protection, reverse polarity – if we put the batteries upside down -, among others.
Featured Models
Hama Eco – Battery charger
Hama
The best : price, simplicity, allows you to charge AA/AAA batteries.
The worst : no electrical protection, no smart charging, slow charging, no end of charge indicator.
The Hama Eco charger is one of the most basic models on the market, in fact, probably the most interesting thing is its price : 5.73 euros on Amazon.
However, it allows charging up to 4 AA or AAA batteries at the same time, although in pairs. It is made of plastic without too many details except for an LED light to indicate that the charge is taking place properly, but it does not indicate when it has finished. Considering the intensity it provides, you will have to leave your batteries charging overnight .
HAMA ECHO
battery type
AA/ AAA NiMH batteries
Number of batteries
4
upload speed
Charge current in AA: 450 mA / Charge current in AAA: 200 mA
Screen?
Nope
Smart charging?
Nope
Protection
Nope
Hama 00087089 – Charger for 4 Batteries (AA/AAA, LED), Color Black
Today out of stock on Amazon
Amazon Basics
The best : with a USB port, overload protection, simplicity, allows you to charge AA/AAA batteries, price.
The worst : no smart charging or screen.
Very similar in design to the previous model is the Amazon Basics charger, which also has an LED light to indicate charging by pairs of batteries, although this one does inform both of the correct charge and the end of it. This charger is much faster, achieving charging speeds of less than 4 hours and stopping the flow of current when charging is finished.
A very interesting feature is the USB port on the side , which, although quite slow, allows you to charge a mobile or tablet at the same time.
AMAZON BASICS CHARGER
battery type
AA/ AAA NiMH batteries
Number of batteries
4 + USB port
upload speed
AA :1800-2000 mAh for 3-3.5 hours, 2100-2300 mAh for 3.5-4 hours, 2300-2500 mAh for 4-4.5 hours. Type AAA 700-800 mAh from 2 to 2.5 hours and 900-1200 mAh from 3 to 3.5 hours. USB port 0.5 Amps.
Screen?
Nope
Smart charging?
Nope
Protection
Protection against wrong polarity charging and overload
Amazon Basics Ni-MH AA and AAA Battery Charger with USB Port
Amazon Basics Ni-MH AA and AAA Battery Charger with USB Port
Today on Amazon for €11.85
Panasonic Eneloop Smart Fast Charger
Eneloop
The best : individualized loading, simple, intuitive control.
The worst : no screen, price.
Although its basic Panasonic BQ-CC51E charger is one of the most popular on the market, this Panasonic Eneloop model is fast and smart, being able to charge a couple of batteries in an hour and a half .
It has a color strip that reports the degree of charge of the batteries in an intuitive and individualized way that, although it does not provide quantitative information on the state of charge, it does give a quick idea. It is possible to charge the batteries one at a time and not in pairs as in basic models.
PANASONIC ENELOOP SMART FAST CHARGER
battery type
AA/ AAA NiMH batteries
Number of batteries
4
upload speed
2 batteries: 1.5 hours / 4 batteries: 3 hours.
