Monday, March 27, 2023

Laptop batteries – device and possible problems


Independence from the mains is one of the main advantages of laptops compared to desktop PCs. But batteries have a limited resource, and during use, various malfunctions can occur that greatly limit the autonomy of the device.

In fact, the battery is a consumable item that must be replaced periodically. Even careful handling and compliance with the operating rules will not protect against this, although this approach significantly extends the battery life.

What are laptop batteries
Batteries for laptops are divided into categories according to the following criteria:

laptop model . The reason for the division lies in the design of the housing and the output of the contacts. Manufacturers often use the same battery in several laptop models, so one battery can be compatible with several devices at once.
Battery type . The power supply characteristics and operating conditions depend on this. Compatibility and interchangeability are not provided.
Number of batteries . The standard is 6–8 units, but the actual range is 3–12 items.
capacity . This characteristic shows how long the laptop can work on a single charge.
Voltage . Notebook manufacturers give their recommendations on this matter, which are strongly not recommended to deviate from. The exact value or range can be found in the laptop passport or on the sticker of the original battery.
Not all laptop models come with removable power supplies, which causes some difficulty for a user who wants to replace the battery. The battery life is 2-3 years, but a branded battery with high-quality cells can work 2 times longer, although the decrease in autonomy will be noticeable.

Speaking about the operating time on a single charge, we can also recall the existence of batteries with increased capacity. The durability of the power supply directly depends on the quality of the elements and assembly.

Element types
There are 4 types of batteries:

Today, the most popular type of battery is Li-on . The battery provides laptop autonomy within a few hours, but the supported temperature range is much less.

Li-polymer is a further development of li-on technology. It does not use a liquid electrolyte, which allows to reduce the size of the battery, but the main difference is the high energy return. Li-polymer is rarely used in standard laptops, at least not yet.

memory effect
The memory effect is a state in which the batteries “remember” the given amount of energy as 100%. The property is typical for nickel power supplies. This is one of the reasons why the battery had to be discharged “to zero” before charging, otherwise a new battery in a couple of months may have a capacity several times less than the declared one.

It is believed that lithium batteries do not have a memory effect, although in recent years this statement has been repeatedly challenged.

Battery internals
A laptop battery has a fairly simple structure and consists of three main elements:

connected batteries,

This example demonstrates a standard Li-on battery, consisting of 6 cells connected in pairs in a serial chain, and a controller responsible for their correct operation.

The image below shows what a Li-polymer battery looks like.

Battery recovery using software
Battery failures are of software or hardware origin.

Software tools are used to eliminate controller errors, diagnose and prevent malfunctions. To do this, there are many third-party utilities, including AIDA64 , BatteryCare , BatteryBar , BatteryMon , BatteryInfoView and many others. In addition, many laptop manufacturers provide proprietary utilities for monitoring battery status and diagnosing problems.

Please note that in order to perform diagnostics and calibration, you must change the power plan in Windows. Otherwise, the operating system will not allow you to perform the procedure correctly by putting the laptop into hibernation. To disable the option, you need to open the selected Power plan, go to ” Change advanced power settings “, and in the proposed list find the ” Battery ” tab.

To diagnose a controller error, you can use the command line in Windows by typing the powercfg energy command . After 60 seconds, a link with the location of the testing report file will appear in the window.

In the report, we are interested in the items ” Estimated capacity ” and ” Last full charge “. Parameter mismatch means the need for calibration . For these purposes, it is recommended to use automatic calibration in the proposed utilities. The battery calibration function is also present in some BIOS versions, from where it can be carried out without starting the OS.

For manual calibration, you need to fully charge the battery, then turn off the PSU. Use the laptop until it is turned off, and immediately connect the charger. The longer a discharged battery is left uncharged, the more likely it is to malfunction.

Sometimes a manual BIOS reset helps. To do this, you need to disconnect the laptop from the network, remove the battery, and hold the power button for 20 seconds. After that, connect the power, and in the settings do a factory reset in the BIOS. Then turn off the laptop, insert the battery and turn on the device.

DIY laptop battery repair
If the problem could not be solved by software, then the reason lies in the malfunction of the batteries or the controller.

The first difficulty will be the disassembly of the battery. First you need to unscrew all the screws: some of them can be hidden under the stickers. Often, manufacturers solder the case, which makes it difficult to open it. In this case, you will need a thin sharp knife or a hot blade. The cuts must be made very carefully so as not to damage the wiring, the controller, or the batteries themselves.

You need to start by inspecting the controller. There should be no visible traces of burnt components on it. You also need to ring the fuse (resistor).

To check the performance of the elements you will need a voltmeter . Pairs of working elements will show 3-4 V, non-working ones – usually 0. With a deep discharge, but serviceable elements, the value is usually 2.7 V or less. If the cause of the malfunction is in a deep discharge, then you can charge directly without a controller using an external iMAX B6 charger or analogues in balancing mode. In this case, you do not have to disassemble the circuit: just unsolder any of the controller contacts. In this case, you need to be very careful and monitor the absence of overheating.

A common occurrence is when several elements become unusable, although the rest could still work. As a rule, “banks” deteriorate in pairs due to pairing in the scheme. In this case, one element takes over the entire load for the non-working “partner”, because of which it starts to overheat and also quickly becomes unusable. Typically 15-30 charge/discharge cycles. The possibility of a closure cannot be ruled out either.

Li-on batteries use standard 18650 cells, so many users are enthusiastic about the possibility of replacing failed batteries with new ones on their own. There is one problem here: when replacing elements, you need to reflash the controller, so it is better to entrust repacking to competent craftsmen.

Very often, craftsmen buy up failed laptop batteries for further use of batteries in various home-made devices. For example, as a power bank, a power source for flashlights. Sometimes they even manage to revive a faulty “jar”. What is the danger? If the problematic elements are actively exploited or feed a sufficiently powerful device, then there is a possibility of their overheating, followed by a fire or explosion.

Notebook battery problems, possible causes and solutions
The following is a list of common laptop battery problems, as well as possible solutions to the problem.

Laptop drains fast
Possible reasons:

controller error,
natural degradation of the battery,
power supply failure.

Manifestation : the charge level drops rapidly, the battery life is reduced to several minutes, the laptop shows a full charge for a long time, and then quickly discharges. In rare cases, the charge level loops at a certain point both when charging and when discharging.


Run diagnostic utilities.
Carry out calibration.
Take the battery to the SC for diagnostics and repacking.
Replace with a new battery.
The need for repair and replacement can be indicated by significant heating of the case, swelling of the elements, which can be seen even in the case.

Laptop not charging
Possible reasons:

charger failure,
physical damage to the socket or plug,
controller malfunction,
deep discharge,
violation of storage conditions,
critical damage to the batteries.
Fade in: Battery level stays at 0, battery indicator may be missing or displayed as a cross. PSU, socket or battery gets very hot.


Make sure the socket is working.
Check the cable of the connected PSU.
Check the condition of the socket and plug.
Try another compatible charger if available.
Take the battery and PSU for diagnostics.

AC adapter Delta+ ETL-3122000
The culprit in this situation is often an external PSU, cable, plug or connector. In other words, such a problem is not always caused by battery malfunctions. To verify this, just disconnect the battery, connect the power and turn on the laptop. If everything works, then the problem is in the battery.

The battery case gets very hot

increased load;
high internal resistance;
problems with the cooling system;
bad layout of laptop components.
Manifestation : the battery began to heat up evenly or unevenly, swollen elements can be observed even through the plastic case.


Check the temperature of the processor and other components.
Check the quality of the cooling system. If necessary, replace the thermal paste, clean the air channels and check the operation of the fan.
It is possible to charge the battery cells on an external charger to check their temperature outside the case, but this is a labor intensive task.
Send for diagnostics to the SC.
Replace battery.

Heating up the battery during operation or charging is a natural process, but if the battery case becomes really hot, then this is a reason to sound the alarm.

Overheating can be the cause or effect of battery failure. Close proximity to the processor, hard drive, and other hot components can cause the battery case to heat up. Sometimes this is a manufacturer’s defect, but more often – problems with the cooling system. High temperatures are bad for the battery: they accelerate wear and tear and can damage the battery shell. Swollen “banks” require an early replacement – such elements cannot be used and charged.

Laptop stand Trust GXT 278 black 2 299 *
The battery will not fully charge

controller failure;
natural degradation of elements;
utilities work.
Manifestation : the laptop regularly charges to a certain level and then does not gain charge; the percentage of maximum charge may vary slightly between cycles or steadily decrease; heating of the battery case when the limit is reached.

Solution options:

Software diagnostics.
Disable power management related software.
Battery Replacement.
Various utilities for diagnostics and power management have already been mentioned. Some of them implement the function of limiting the maximum charge, which will be discussed in more detail in the next paragraph. Before you start repairing or replacing the battery, you need to exclude the influence of these programs.

How to extend laptop battery life
In fact, creating conditions for maximum battery life is not so difficult. First you need to study the operating rules in the laptop passport and on the sticker of the battery itself. In addition, you need to take into account the specifics of the type of batteries.

This is especially important for laptops with non-removable batteries, because their maintainability is much lower. As a temporary alternative to a failed built-in battery, you can use a powerful power bank. Of course, this option should be considered as a temporary solution.

List of recommendations for the prevention of laptop battery failures.

Avoid body shocks, overheating of the surface and careless handling of the connected PSU plug. The laptop must be placed on a flat hard surface. Putting a laptop on a bed, blanket or knees is strongly discouraged – this will block the ventilation holes, which will lead to an increase in temperature under the case.
If the laptop will not work for 10 or more days, then the battery should be charged to 60-80%, and put it in a dark, cool place.
The optimum operating temperature for the battery is +20°C. The operating range includes temperatures 0… +40 °C (lithium). If the battery gets hotter, wear will accelerate, there is a possibility of fire, explosion, damage to the shell and leakage of electrolyte.
Perform calibration 2-4 times a month.
Avoid completely discharging the battery to 0% except when calibrating.
Monitor the state of the battery using the previously mentioned software.
For lithium batteries, not only a full discharge is harmful, but also a constant full charge, although the controller eliminates such a phenomenon as overcharging. It is recommended to periodically discharge the battery to 10-15% and then connect the charger. Do not store the battery fully charged.
When running on battery power, it is better to avoid running “heavy” programs and games.
To prolong battery life, I often advise not to use it by disconnecting it from the laptop. The device is intended to operate directly from the network. In practice, this is inconvenient.

In such cases, you need to remember that the battery is a consumable item, and its replacement is a matter of time. Careful handling and compliance with the rules of operation will help to preserve the working life longer, providing a comfortable working environment for a laptop.

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