Nothing is more annoying when you don't have a charger on hand or something to plug in your laptop to recharge its battery! Well, you no longer have to worry about such an incident happening: the External Battery will revolutionize your daily life!
Contrary to what is commonly accepted, the External Battery is not only used to charge your mobile phone, tablet... but also your laptop. So it’s time for you to get one! The question is how to make the best choice for your laptop?
Please note that for an external PC battery model to be suitable for your laptop, it must meet a series of rules:
- A compatible connector
- The same operating voltage (V)
- Power supplied must be equal to or greater (W)
Through this guide, you will learn how to identify the External Battery that is best suited to your laptop.
The characteristics of your laptop charger
In order to find the perfect external battery for your laptop, you must first know the characteristics of the latter.
Let's take the specifications of this portable charger as an example:
In the output, we find:
- Voltage: 19V
- Current: 4.74A
- Power: 19V x 4.74A = 90W
This means that this charger operates at a voltage of 19V (volts) and delivers a maximum current of 4.74A (amps), as well as a maximum power of 90W.
Finding out the specifications of your laptop will help you avoid damaging it. Indeed, if you connect it to a charger (or an external battery) with a higher voltage, this could cause collateral damage .
The prerequisites for adapting an external battery to your PC
To be able to replace your charger with an external battery, you should take into consideration the following characteristics:
Charging port:
There are three different ways to power your laptop via an External Battery, depending on the output port:
External battery with DC port:
When using this type of battery, please check that the external battery connector is compatible with a port on your laptop. Typically, a set of adapters is included with this type of External Battery.
However, it is rather difficult to find a suitable model for your laptop. Not to mention the fact that these batteries are bulky and require a wall outlet to be recharged.
External battery with AC port:
With external batteries including a 220V AC port, you can say goodbye to incompatibility problems! Thanks to them, you can directly connect your laptop charger. Pretty simple, right?
However, this battery is not perfect either. There are some drawbacks such as large dimensions, an additional AC charger, and the worst is that some of the power from the External Battery is lost when using the device's charger as a "middleman".
External battery with USB-C PD port:
USB Type C represents the future of connectivity! You can charge any device using a universal USB C charger, without having to search for compatible connectors.
Equipped with the brand new PD (Power Delivery) technology, it can also power high-power devices (Fast Charge).
If you have a latest generation laptop, an External Battery with PD is what you need!
Otherwise, you will need to use a special adapter or cable that has a USB-C (External Battery) connector on one end and an INPUT DC (laptop) connector on the other.
This is why you must be extremely careful when purchasing the cable, so as not to damage your PC.
Let's imagine we have a 20V charging laptop, it will only be able to start charging after being connected to a 20V PD cable.
If the cable is less than 20V, the computer will not charge, and if it exceeds 20V, the computer will be irreversibly damaged.
Output voltage (V)
If you have an External Battery with a DC or USB-C PD output, don't forget to check that its output port has the same voltage as your laptop's charger, to avoid any problems.
The output voltage is usually listed in the Power Bank specifications as “DC Output” or “USB-C Output”.
What happens if my laptop charges at 19.5V*?
In reality, any electronic device must withstand a voltage of + or -10% of its nominal voltage. This means that if your laptop charges at 19.5V, it supports a maximum voltage of 21.45V (19.5V + 1.95V), and therefore a 20V external battery could charge there. be connected.
In addition to this, it is necessary to take into account the voltage drop that occurs in the cable connecting the External Battery to the laptop, which varies between 0.15 V and 0.2 V for each meter of length (depending on the resistance of the cable itself).
Suppose the output voltage of the Power Bank is 20V, then the laptop would get a voltage of 19.8V (20V-0.2V).
We also find models having one or more DC output ports with a fixed voltage or a single multivoltage DC port, the voltage of which can be selected to the charging voltage of our laptop (by pressing the "power" button).
On the other hand, if you use an External Battery with AC output, it is not obligatory to check the voltage, since the charger used will be that of your Laptop, the latter automatically transforms the 220V voltage into the computer's charging voltage. .
Power supplied (W):
The last criterion to take into account is the maximum power that the output port of the External Battery is capable of providing:
We know that a computer needs maximum power when starting up. That said, it is recommended to use an external battery that can provide the same power as the charger or more.
But this time, in the following section, we will see some situations in which it is possible to use a lower power model:
Guide to choosing your external battery:
First of all, we will see what should be checked depending on the type of external battery chosen to recharge our laptop:
Battery Type
External battery with DC port
- Check the voltage (V) and power (W) of the computer charger.
- Find an External Battery with a DC output port, having the same voltage (V) and equal or higher power (W). You may face certain problems:
- You may not find a model with the same tension.
- You may also not find a model with the same power, or not want to spend a lot of money.
- Verify that the External Battery has a cable and/or connector compatible with the computer's charging port.
External battery with AC port
- Check the power supply (W) of the computer charger.
- Use an AC external battery of equal or greater power (W) than that of the charger. Here too, you may still not find a model with the same power, or you may not want to waste your money.
External battery with USB-C PD port
- Check the voltage (V) and power (W) of the computer charger.
- Find an External Battery with a USB Type-C output port, having a Power Delivery (PD) of the same voltage (V) and power (W) equal or higher. Possible problems:
- Can't find a model with the same voltage.
- Not finding a model with the same power, or not wanting to waste your money.
How much power does an external battery need to charge a laptop?
Depending on the laptop model, your charger will be designed to provide a maximum power of 45W, 65W, 90W, 130W…
However, you may not find an external battery with a power equal to or greater than that of your charger, or you simply want to save a little money. In this case, you can purchase a less powerful external battery, but subject to certain conditions:
Battery Removal
Removing the laptop battery:
When the battery is removed from the laptop, the power of the External Battery required by the PC becomes lower than that provided by its charger, since the energy intended to recharge its battery is no longer necessary.
Keep in mind that the power required to start a computer is always higher than the average working power, due to the peak current produced.
A tip that will help you avoid peak startup current would be to activate sleep mode when the computer tells you that its battery is low. Then, you must connect and then extract the external battery from the laptop. If you now deactivate sleep mode, you will already be able to take advantage of the power of the External Battery without having to experience this power peak at startup.
If you follow these conditions of use, you will be able to use an External Battery with a lower power than that of your charger, provided that it provides at least 70% of the power of your charger. In other words, if your charger is 65W, the power of the External Battery must be at least 45W.
Charging PC off
Charging the battery with the laptop turned off:
An alternative would be to keep the laptop powered off while recharging it.
This means that you will only need the power required to recharge the laptop battery, this power being the same as the previous condition (45W) (at least 70% of the power of your laptop charger ).
Recharge while on
Charging the laptop and using it at the same time:
If you are not satisfied with the options mentioned above, you can also use a weaker external battery before the computer battery completely discharges (generally less charging power is required from 50% battery) .
So, when you connect the External Battery while the computer battery is still not exhausted, you avoid excessive power at the starting peak.
You definitely need to know your laptop's starting peak, as well as how much power it needs to recharge its battery (while it's still half charged).
After reading these 3 tabs, we recommend that if possible you use an External Battery of the same power or higher power than that of the laptop charger, while respecting the conditions of use.
How many hours can I use a laptop with an External Battery?
Are you already thinking about buying an external battery for your laptop? Well, first of all, ask yourself the following questions:
- What tasks will you typically use your laptop for with an external battery? Surfing the internet, office automation, playing games, watching Netflix...? You will need to determine the average consumption of your computer.
- For your chosen task type, how many hours does your laptop last on a 100% charged battery?
- What type of external PC battery will you use? With a DC, AC or USB-C power supply port?
Calculating the average consumption of a laptop
Do not panic ! You don't necessarily need to have high knowledge or specialized devices to know what your PC consumes when you use it daily, you can find out by taking a closer look:
- The energy stored in your laptop battery.
- The estimated duration of tasks you typically perform with your laptop.
You will find in the battery specifications an indication of the energy stored in the laptop battery, measured in watt hours (Wh). Otherwise, you can calculate it by multiplying the voltage (V) by the capacity (mAh) of the battery (image on the left 15 V x 2950mAh): 44Wh
Remember that a laptop battery wears out as you use it: its capacity gradually decreases over time. That said, it is very likely that the energy stored in the battery is less than that indicated in its specifications, especially if your computer is several years old and you have never renewed the battery.
If you want to know the health of your laptop's battery, know that there are a large number of applications on Windows 10, designed specifically for this.
Once you have determined the power of your laptop's battery, all you need to do is divide it by the time (in hours) your laptop lasts when fully charged (100%):
Average consumption (W) = battery energy (Wh) / usage time (h)
In our theoretical case, the battery of an Acer laptop is 44Wh and its charging time in daily tasks is usually 3.5 hours. So the average consumption of our laptop will be:
Acer average consumption = 44 Wh / 3.5 h = 12.8 W (watts)
In addition
It is obvious that the consumption of our laptop, as well as the life of its battery, vary depending on the tasks carried out at that time. For example, surfing the net is nothing compared to playing a game that uses both the CPU and GPU of our PC to run at maximum!
Computer autonomy with an external battery:
Now that you have chosen your External Battery, it is time to calculate approximately the theoretical time during which you will use your computer for a certain usual activity, whether watching series, office automation, surfing the internet, playing online... and also depending on the charging mode: battery removed, computer turned off or using it at the same time:
Calculate the average consumption of a laptop
- Check the average duration (in hours) of the laptop with the battery fully charged, based on the type of activity usually performed.
- Check the laptop battery power (Wh).
- Apply the formula: Average consumption (W) = battery energy (Wh) / usage time (h)
Calculate the useful energy of the External Battery
- Check the energy (Wh) of the External Battery.
- Calculate the energy to use the computer and/or to recharge its battery, depending on the type of external battery:
- DC or USB-C PD external battery: Useful energy = External battery energy x 0.7225
- AC external battery: Useful energy = External battery energy x 0.6141
Calculate laptop battery life
- Laptop battery removed:
- Duration of use (h) = useful energy (Wh) / average consumption (W)
- Recharge the battery with the laptop turned off:
- Number of charges = useful energy (Wh) / PC battery energy (Wh)
