Choosing the right battery is one of the most important things to do to exploit the potential of your power tool, but finding your way among the products offered by the market can sometimes be difficult for a less experienced public who consequently risks buying a battery that does not meet their expectations: discover with our advice how easy it is to find the perfect battery for each power tool.
Rechargeable batteries are essentially batteries whose electrical charge can be restored through the application of a specific and adequate electrical energy.
In fact, the fundamental characteristics of a battery are its capacity, expressed in Amperes per hour or Ah, and the voltage at the terminals, expressed in Volts or with the abbreviation V.
Usually each battery has in its name or model the type of voltage and capacity; it is advisable to always pay attention to these parameters when choosing the battery to which you entrust your power tool and when choosing the charger for charging it.
They exist on the market different typologies of batteries that differ not only in voltage And electrical capacity, but above all for chemical composition And size.
Among the most commonly sold secondary batteries for power tools are lithium-ion batteries, nickel-metal hydride or NiMH batteries, and nickel-cadmium or Ni-Cd batteries. But what is the difference?
Lithium batteries can be manufactured in different sizes and shapes, thanks to theextreme versatility of Lithium ions. This feature makes these batteries an efficient charging tool and an effective workspace optimizer. The Lithium battery is very light of equivalent batteries manufactured with other components. This is due to thehigh charge density of lithium ions and the fact that lithium requires fewer intermediates for storage, thus leaving more room for charging.
The accumulators Lithium-ion charging they do not present any memory effect and show a low self-discharge rate, which is approximately 5% on a monthly basis. This self-discharge rate is mainly due to the internal consumption of the voltage monitoring circuit.
Among the disadvantages of lithium ion batteries is the presence of degradation even when not in use. A lithium battery should never be discharged below a certain voltage so as to avoid irreversible damage.
It is therefore important to check that lithium batteries are equipped with a special circuit that turns the battery off if it drops below the predefined threshold. Another problem related to lithium ion batteries is due to overheating. If these are left near sources of excessive heat or poorly ventilated, there is a risk of their overheating and a consequent leakage of dangerous liquid. As a rule, a good lithium current accumulator requires the presence of various safety systems such as a thermal switch that prevents overheating in the event of overload, and a safety tab with a relief valve to control the internal pressure.
The Nickel-metal hydride or Ni-MH battery has two or three times the capacity of the homologue (same size) to Ni-Cd and a less significant memory effect.
The most common applications for this type of battery include consumer electronics such as digital cameras but also hybrid products such as new generation cars.
They very often replace Nickel-Cadmium batteries if the power tool requires a higher power supply current.
Ni-Cd batteries use the metals nickel and cadmium as chemical reactants. Nickel is the cathode while Cadmium is the anode.
The advantages of Nickel-Cadmium batteries include: less need for care and ease of damage, The longer lifespan, calculated in charge-discharge cycles, no damage due to not charging for a long time, shorter charging time.
All these advantages, however, mean that nickel-cadmium batteries are relatively expensive compared to lead-acid ones.
Ni-Cd batteries have a self-discharge rate of around 5% on a monthly basis.
Most of them have a thermal isolation system that allows them to stop charging if the temperature is too high. Sometimes this causes the battery to stop charging if it is charged immediately after use.
These batteries contain cadmium which is a heavy and toxic metal and therefore requires great care in its disposal. This is one of the factors that most affects the price of these batteries, which often includes a percentage dedicated to environmental protection.
This battery was created to meet the increasingly frequent requests from end users, requests that require greater autonomy, without allowing changes to weight or dimensions.
The development of this battery has responded satisfactorily to market demands, a battery that has maintained identical dimensions and weights to the previous 3.0 Ah and 4.0 Ah versions. Today we can talk about product development and evolution, we can see first-hand what the path taken by Makita to always be at the end user's side.
The charging system is still one of the main features that differentiates Makita from all others; the new 5.0 Ah battery has a total charging time of just 45', the result of huge investments in research and development.
The technology Makita It actively controls the temperature of the current and the voltage of the individual cells that make up the battery, thus guaranteeing a charging cycle of 22 minutes for the 3.0 Ah version, 36 minutes for the 4.0 Ah version and only 45 minutes for the 5.0 Ah version.
There are two main issues to take into consideration if you also want your battery to last a long time: storage temperature and charge and the safety in use of the product.
Unlike nickel-metal hydride or nickel-cadmium batteries, lithium-ion batteries require a very frequent charge-discharge cycle, in fact we recommend that you never completely discharge them or store them discharged.
If a Li-ion battery is charged it should be used immediately, while for their storage most manufacturers recommend a charge percentage of around 50% and cold temperatures, such as those of a home refrigerator.
As far as safety is concerned, it is always important to keep in mind that batteries can be easily damaged, both by high temperatures and by being dropped. Never ever to short-circuit the battery, as this practice could lead to fire or dangerous leaks for both the user and the environment.
Never open the external battery container, as it very often contains battery safety devices which, if tampered with, could interrupt the battery's operation.