Charged Drill Battery Replacement
Information on Cordless Drill Batteries
Cordless drills contain battery groups with various chemistries. These batteries lose performance over time and will never reach their original capacity again. The thing to do for cordless drills is to renew the batteries when the battery life ends. Battery regeneration of cordless drills is done using special battery centering machines. These battery groups are usually connected in series and adapt to the operating voltage of the drill. In some drills, parallel groups can be added to series groups. The reason for this is to increase the working time of the drill. Cordless drill battery repair is not a simple process. It is necessary to have knowledge about the chemistry and properties of batteries.
Cordless Drill Battery Types
Motors in cordless drills draw high current. Therefore, not all types of batteries are used in the drill. Generally used battery types are Ni-Cd (nickel cadmium) and Li-ion (lithium ion) batteries. These batteries have features that distinguish them from each other. Let's examine them now;
Ni-Cd Rechargeable Drill Batteries
These drill batteries are considered old-fashioned. Although it is an old battery chemistry, they allow to draw current up to 3 times (3C) or even more than its capacity. Thanks to this feature, it is used in tools that require high power such as cordless vacuums and cordless drills. These types of batteries have less self-discharge than Ni-MH (nickel metal hydride) batteries.
One of the biggest problems of Ni-Cd batteries is that they are toxic. This has serious effects on the environment. They have low energy density and take up a lot of space, both heavy and bulky. Another problem with these batteries is that they have a memory effect. Charging these types of batteries before they are completely discharged or removing them before they are fully charged reduces the battery capacity. If we summarize briefly and list the features of these batteries; They are economical, they can give high current, their self-discharge rate is low, their energy density is low, they contain toxic substances, their volume is large and heavy, their capacity is low, and they have a memory effect.
In order for Ni-Cd drill batteries to have a longer life; When not in use, it should be completely discharged and put away, should not be charged before the battery is completely depleted, should not be used without being fully charged, and should be kept for a long time since it is charged for the first time (for once).
Li-ion Cordless Drill Batteries
It is a much more technological type of battery than other battery types. These batteries, which have high energy densities, take up little volume, are light and can hold a lot of capacity. They were too costly when they first came out, but with the advancement of technology and the acceleration of mass production, they have fallen into affordable prices. With the decrease in prices, they have started to be among the frequently used batteries. Among the types of lithium-ion batteries, some of them are advantageous in terms of capacity and some of them are advantageous in terms of giving high current. Cells that can give high current should be preferred for rechargeable drill batteries. Otherwise, the batteries may expire in a short time and may overheat.
As for the disadvantages of lithium batteries, they are dangerous in the first place. If it is not charged within the appropriate voltage range, shocked, over-discharged, and short-circuited, burning and explosions may occur. It can also consume its life in a short time. In order to prevent these situations, it should be used with the BMS circuit. BMS circuits suitable for battery packs may differ. BMS (Battery Management System) stands for Battery Management System. It is the card that performs inspections and measurements during the charging and consumption of the battery.
If we summarize briefly and list the features of these batteries; They are economical compared to other battery types, they can give high current, they do not self-discharge, they are small and light, their capacity is high, there is no memory effect, they can be charged - discharged whenever desired, they should be used with BMS circuit, they can be flammable and explosive and their assembly should be done by people who know their job. The chemistry of both Ni-Cd and Li-ion batteries is suitable for cordless drills, but Li-ion batteries are much more preferred because they have no memory effect and can deliver higher current. Cordless drill battery conversion is also a process that can be done.
In order for Li-ion drill batteries to have a longer life; When not in use, they should be stored at room temperature at 30% full, the batteries should be charged before they are fully discharged and charged after each use, they should not be allowed to be completely discharged, they should be rested for a certain period of time after each charge and discharge (15-20 minutes is sufficient), the batteries should be charged 20% of their own capacity. It should be charged with a current of ' and should be removed from the charge when it is 90% full during charging.
Replacing the cordless drill battery is not a difficult task when it is done by experts. In a distressing situation, a fire may occur, physical (burning, etc.) damage may occur to the person and your drill may become unusable. The batteries must be properly connected to each other during the battery regeneration process. Pure nickel conductors that can carry high current should be used for the connections of the batteries. Otherwise, the conductors may overheat and cause a fire. Conductive wires must be welded to the batteries with a spot machine. One of the most common mistakes is to assemble the batteries by soldering wires or cables directly onto the batteries. This causes the batteries to reach high temperatures and the life of the batteries will decrease, lose their properties and then cause a fire or explosion. Especially not using BMS in lithium ion batteries is one of the biggest mistakes. In this case, the batteries may be overcharged or discharged and may cause fire or explosion.
For rechargeable drills, which are devices with high current draw, batteries that can give high current should be preferred. Non-high current batteries are not suitable for cordless drills, including Li-ion batteries. In addition, it is very important that the BMS circuit to be used is high current. Preferred batteries should have low internal resistance. It is not correct to use batteries other than Ni-Cd and Li-ion for cordless drills.