How Much To Charge The Battery Of A 12 Volt Screwdriver
Rechargeable batteries and batteries Features and requirements for charging lithium-ion and lithium polymer batteries and batteries. Features of protection boards in batteries and controllers in batteries. How to charge the batteries quickly and to a full charge.
How to charge lithium batteries
Lithium batteries are a galvanic pair in which lithium salts serve as the cathode. Whether it’s a lithium-ion, lithium-polymer dry cell or a hybrid battery, the charger fits everyone. Products can be in the form of a cylinder, or a hermetically sealed soft package, the charging method for them is general, corresponding to the characteristics of an electrochemical reaction. How to charge a Li-ion battery?
How to charge a screwdriver lithium battery
A lithium battery screwdriver is almost always an upgrade. While Ni-Cd cells had the same charging requirements, now they are the opposite. First of all, you need to purchase or assemble a charger, specifically for the power-hungry lithium batteries of a screwdriver with a form factor 18650. The charging scheme is used in two stages CC / CV.
Charging the lithium battery of a screwdriver is optimal when 20-50% of the capacity remains. One stick on the indicator. The more often you charge, the more stable the voltage at the terminals and the longer the life of the energy source. The more even the voltage at the terminals, the more cycles the lithium battery of the screwdriver will withstand.
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If there are 2 batteries in the screwdriver, remove one, charge to 50-60% and keep in reserve. But always charge the second one at the end of work, even by 10%. The best temperature for charging is 15-25 0 С. At minus the battery of the screwdriver will not charge, but it can work up to 10 0.
How to charge the lithium battery of a screwdriver with a charger depends on the battery collection scheme. In any case, the voltage on the charger should be equal to that declared for the device, and the current strength should be 0.5 C at the first stage. On the second, the terminal voltage is stable, and the current falls, until the end of the process.
How to charge a 12 volt lithium battery
Each lithium battery is a sealed product of a cylindrical, prismatic shape, for Li-pol in a soft package. All of them have a voltage of 3.6-4.2 V and a different capacitance, measured in mA / h. If you collect 3 cans in series, you get a battery with a voltage at the terminals of 10.8. 12.6 V. The capacity during sequential charging is measured by the weakest lithium battery in the bundle.
You need to know how to properly charge a 12 volt lithium 18650 or Pol battery. To return the container to the device, you must use a charger with a controller. It is important to have in the PCM assembly for each can, protection against under- and overcharging. Another scheme of unprotected lithium-ion batteries is the installation of a PCB. A control board, preferably with balancers, for uniform charging of the cans.
On the charger, you must set the voltage under which the battery operates, 12.6 V. On the dashboard, the number of cans and the charging current are set at 0.2-0.5 C.
How to charge, we suggest looking at the charging method for 2, 3 lithium 18650 batteries connected in series. A budget charger is used.
Charging options for lithium-ion lithium polymer batteries:
- Charger purchased with the device.
- Use the USB connector from electronic equipment. Computer. Here you can get a current of 0.5 A, charging will take a long time.
- From the cigarette lighter by purchasing an adapter with a set of ports. Choose the one that matches the 12V battery.
- Universal charger “frog” with a dock for installing a gadget. How to charge? There is a charge indication panel.
Experts advise using a standard charger to charge lithium batteries, the rest. Only in force majeure. However, you need to know how to charge a lithium battery without a standard charger.
How much to charge a lithium battery
Battery charging time is determined by the process of restoring capacity. Distinguish between full and partial charges.
Capacity is measured in ampere-hours. This means, if you apply a charge numerically equal to the capacity, then in an hour the required voltage will be created at the terminals, and the energy reserve will be 70-80%. If the capacitance is measured in C units, 1C-2C current should be applied during fast charging. Fast charging time is about an hour.
For a complete charging cycle of batteries from several cells connected in series, 2 stages are used. Cc / CV. The SS stage lasts until a voltage equal to the operating voltage appears on the terminals, in volts. The second stage: at a stable voltage, a current is supplied to the jar, but with an increase in capacity, it tends to zero. Charging time takes about 3 hours, regardless of capacity.
Main types of screwdriver batteries
Screwdriver batteries: lithium Li-Ion, nickel-cadmium Ni-Cd, nickel-metal hydride Ni-MH.
Manufacturers of screwdrivers use different batteries in the production of their units, which have their own characteristics of operation and, accordingly, charging. In order for the screwdriver to work without failures for a long time, it is very important to carefully read the instructions that come with it. It should be noted that different screwdrivers differ in many parameters, including price, quality and power, therefore all screwdrivers are divided into semi-professional and professional. Accordingly, the batteries that are installed by the manufacturer also differ in price, quality and, most importantly, in charge capacity.
In professional models, which are more expensive, as a rule, batteries with a larger capacity are installed, so they can work without recharging for a much longer period of time. Most professional builders have a spare, pre-charged battery for uninterrupted work, but if the screwdriver is designed to perform simple housework, it is not necessary to have a second battery, although in some cases an additional screwdriver battery is included with the unit. There are 3 main types of batteries that are most often used in screwdrivers:
- Nickel metal hydride.
Screwdriver battery connection diagram.
The most widely used today are nickel-cadmium batteries for screwdrivers. This type is distinguished by its rather compact size, relatively low cost and large charge capacity. The main drawback of these batteries is the same “memory effect”, but with proper use and recharging, batteries of this type can be recharged more than 1000 times, although it should be noted that even with proper use, the charge capacity will gradually decrease until it reaches a minimum. Among other things, it should be noted that such a battery contains highly toxic substances, so their production is significantly harmful to the environment, which has become the reason for their ban in many countries.
Nickel-metal hydride batteries are in second place in terms of frequency of use. Batteries of this type belong to a new generation, as they are completely safe for the environment. This type has a lot of advantages, the main of which is the absence of a “memory effect”. However, it is worth noting that they have a high self-charging current, and these batteries should be stored exclusively in a charged form, and if the screwdriver is not used for a month, it is necessary to discharge the device and recharge it again.
Lithium-ion batteries are a relatively new product in the market for these products. They do not have a “memory effect”, therefore, they do not require adherence to recharge cycles to restore the charge capacity. It takes very little time to fully recharge these batteries, and their capacity is quite high. However, these batteries also have disadvantages, including reduced performance in cold weather and a rather high cost.
How IS IT CORRECT AND HOW MUCH TO CHARGE THE SCREWDRIVER BATTERY?
Screwdrivers have long been invariably popular not only among professional builders, but also among ordinary people, because these units are indispensable when you need to screw something or, conversely, untwist it. The versatility of screwdrivers is the main reason for the popularity of these units, both in everyday life and in large construction, but all users of these units have a lot of difficulties when it comes to recharging the batteries with which most screwdriver models are equipped.
Diagram of the structure of the screwdriver.
The thing is that with incorrect charging, the so-called “memory effect” appears, that is, under certain conditions, the charge capacity may decrease, and in the future the unit will be discharged less completely. As a rule, this effect occurs when a person tries to recharge an incompletely discharged screwdriver battery. Proper charging of screwdriver batteries has a lot of subtleties, so it is very important to consider all aspects of this matter so that the screwdriver retains its functionality and performance for a long time.
Features of charging screwdriver batteries
Charger circuit for a screwdriver.
A very important point is the first charging of the screwdriver, since it depends on it whether the full charge capacity will be activated. Each type of battery has its own characteristics of primary charging. The biggest challenge is charging nickel-cadmium options. Their first recharging should be three times so that the entire charge capacity is filled. Thus, after the purchase, the unit must be fully charged, then turned on and left to work until it is completely discharged, then you need to put it back on to recharge and discharge again, and so on 3 times.
For the first time, the nickel-metal hydride version should be completely discharged immediately, because, as a rule, when you buy such a battery has a small charge, after that you need to leave it to fully charge. Recharge this type of battery only after it has been completely discharged. The full charge-discharge cycle should be considered the first 4-5 times, after which you can additionally recharge the batteries, even if they are not completely discharged.
Table of characteristics of screwdrivers.
Lithium-ion batteries are more modern, so there are no special requirements for recharging them, since their capacity does not decrease in any case.
During the first and subsequent recharging, it must be borne in mind that the most optimal recharging effect can be achieved only if this process takes place at a temperature of 10 to 30 ° C. Among other things, it should be noted that when charging, some types of batteries may begin to heat up, which can have an extremely negative effect on the entire battery. Do not allow the entire battery to overheat above 50 ° C. It is best to store the battery separately from the screwdriver after work, although this is not necessary.
What voltage and current is harmless to charge a car battery
We decided to write this article when we came across one of the “service centers” for charging the battery. The chargers were. Diode bridge transformers. Even more disappointing were the advice on the Internet: “unscrew the cans before charging”, “find a charger supplying voltage 16 V-16.5 V”, “get good gas emission”, “charge for a long time with low currents.”
We recommend unscrewing the plugs in the battery before charging (if any) to owners of Chinese or grandfather’s chargers. Such storage devices are assembled according to the scheme “transformer plus diode bridge”. Voltage can be given by any, albeit 20V. Boiling when charging the electrolyte will be such that the case will rupture.
Do not charge batteries brought from frost, let them warm up indoors for several hours. Also, batteries that are too hot cannot be charged. Charging is most efficient and safer at room temperature.
It is practically useless to charge a battery discharged below 8 Volts, most likely one of the cells in it is short-circuited or polarized. A conventional charger will not be able to fully charge a strongly unbalanced battery: the voltage at the current leads will not exceed 12.5-12.6 Volts. Such batteries can only be cured (fully charged) by specialists. It is necessary to charge the lagging weak banks separately with a voltage of 2.4 Volts with a current of 0.1 of the capacity of the entire battery in a pulsed mode.
Important ! The operating voltages of a modern battery, below which CANNOT be discharged 10.8 V and above which CANNOT be raised when charging 14.4 V.
The 15-16 volt voltage that most cheap Chinese chargers are charged with is a strong boil that destroys the smears on the electrodes with bubbles. The resulting sludge does not fall to the bottom, but remains on the plates, retained by separator envelopes. The electrolyte’s access to the active mass of the electrodes is partially blocked. Capacitance and cold start current drop.
In old battery designs, boiling during charging did not bring such consequences. The sludge fell to the bottom. In the place assigned to it.
At a charging voltage of 16V, if you do not unscrew the can caps and do not let the gases escape, the battery will simply swell or crack its case. At normal charging voltage, the cover does not need to be unscrewed. Some batteries simply do not have them.
Important! A defective battery can be detected during charging. A battery that has lost its performance is not capable of accepting charge currents above 1-2 Amperes. The sign of a battery that has died from strong sulfation is as follows: even at low charging currents, the voltage immediately rises to a maximum of 14.4v. The battery voltage (12.7-13 V) gives the impression that it is fully charged. Inadequacy is indicated by a test with a load plug or a car starter. The voltage at the terminals instantly drops, the engine does not start. This sulfation is most likely already irreversible and the battery should be disposed of.
Important! Do not apply when charging a current above 1/10 of its capacity, too small currents below 1/20 are also useless. For standard 60 Ah batteries, normal charge currents are from 3A to 6A (7-9 Amperes when charging in “current supply-pause”). In the battery, the charge current triggers chemical reactions. The reactions depend on the amount of active mass on the plates and its thickness, the area of the electrodes, the temperature range, and the undesirable process of water electrolysis. A weak current will not charge the entire volume of the electrode spread, but only its topmost layer. Then the voltage rises to 14V and above, signaling the end of the charge. Water electrolysis starts. It is impossible to continue charging such a battery with a low current, since the electrodes will passivate. The plates will lose the ability to accept normal charge currents at all. If the charge currents are too strong, unwanted chemical reactions will appear in the battery, which, in addition, will proceed too violently and destructively. If the charge current is too high for a particular battery, then due to the action “excess current” abundant release of hydrogen and oxygen from the electrolyte begins. Boiling, gurgling in cans. Bubbles destroy the smear layer, and free oxygen oxidizes the lead in the plus plates, turning them into a soft lead oxide that is easily destroyed by vibration “spongy lead”. In a working battery, when the current is cut off, boiling should stop immediately.
It is also harmful to store the battery at a constant low float current. If you charge an already charged battery. The positive plates will oxidize and “boil away” water from the electrolyte. The result will be a battery with corrosive electrodes, weakened bridges and a high self-discharge rate.
The battery charging process must be monitored visually, making sure that the electrolyte does not “boiled”, which usually happens at voltages above 14.4v; and using a multimeter, measuring the voltage and charge current. Cheap antimony batteries are always boiling. There will also be bubbles when charging a sulfated battery. A weak charger (1-2 Amperes of current) will not charge even a 60Ah battery. It will certainly raise the NRC of the battery to 12.7v, but it will add a lot of health problems to the battery. In the case of more powerful chargers, the problem arises “excess current” and a rapidly increasing voltage leading to battery-destructive electrolysis of water. Charge the battery optimally, even “grandfather’s” Charger plugged into the socket through the timer in the trickle charge mode: after a short-term supply of current (10-30 sec), turn off the charger for a while (10 sec), then turn it on and off again. Thus, most of the rules are followed when charging the battery. The charge goes with a strong current, the voltage does not rise prematurely, at the moment the charger is turned off the battery “assimilates” the charge received by chemical processes, the voltage does not rise too quickly, the process “boiling” no water occurs. Charging can be connected via an electronic timer on-off of the socket, or charge through a homemade multivibrator “blinker”. The simplest blinker is made from a turn relay. The schemes are available on the Internet. The on and off times are adjusted empirically based on the characteristics of the charger and battery.
It is best to charge the battery with a modern smart charger that has a “brain”. Cpu. Such a charger is capable of picking up currents and charge voltages and can control them.