If you want to prevent your phone from running out of battery, a good option is to use an external battery. There are many different external batteriesAnd with some of them, it's even possible to charge a laptop battery. However, is it possible to charge your laptop battery with just any external battery?
Can you charge your laptop battery with your mobile phone's external battery?
Charging your laptop battery with an external battery is not impossible. However, only with some external batteries It is possible to charge the laptop battery. Keep in mind that currently, it is only possible to charge the laptop battery if it has a USB Type-C for chargingThis is the case with MacBooks, for example. However, for other laptops, it's not possible to charge the battery using an external battery. This is mainly because the voltage required to charge a laptop battery is around 19V, and external batteries typically operate at around 5V. It's possible to buy an adapter to convert the external battery's voltage to 19V, but the battery's capacity will be depleted very quickly, making it not really useful.
However, if you have a laptop with a port USB Type-CDon't think that buying a 19V compatible external battery is really useful, because it isn't. When charging a laptop battery at 19V, the power consumption will be very high, and a battery that could usually charge a smartphone two or three times will only be useful for charging a small percentage of a laptop's battery. So, in general, it won't be worthwhile to buy one of these batteries that are also compatible for charging a laptop battery.
Furthermore, these batteries are usually expensive, and that price difference It's better to spend it on buy an external battery for our highest quality smartphone.
What do you really need to charge a laptop with a power bank?
Today there are power banks capable of delivering High power via USB-C Power Delivery (PD), sufficient for many laptops. For it to work, check: specific models with high-power USB-C output.
- Laptop compatibility: It must support USB-C charging with PD. Simply having USB-C is not enough; it must accept power through that port. Check that your laptop supports USB-C charging with PD
- Watts required: Check the power rating of the original charger (for example, 45W, 60W, 65W, or 100W). The power bank must to equal or exceed that figure.
- Suitable wire: use a USB-C cable with E-Marker certified for high power levels (especially from 60W).
- Laptops with a round (DC) connector: You will need a power bank with 19V regulated DC output or PD-to-DC adapter Specifically, consider the efficiency and maximum power of the system.
Basic mobile power banks deliver 5 V / 2 A or fast charging geared towards smartphones (QC/PPS) which are not always suitable for laptops. Without a high-voltage/high-amperage PD or without a suitable DC output, It will not load.
Actual capacity, efficiency and times: mAh vs Wh
Capacity is published in mAhBut what's useful for comparing with your laptop are the... Wh (watt-hours). The relationship is: Wh = V Ă— AhIf your power bank is 20.000 mAh (20 Ah) at a nominal 3,7 V, its theoretical energy is around 74 WhDue to conversion and heat losses, the usable capacity is usually around 60-70% of the theoretical.
To estimate the loading time For the power bank: Time (h) = Battery capacity (Ah) Ă· Charging current (A). And for the laptop, think about powerIf your laptop requires 60W and your power bank delivers a stable 60W, the charging speed will be similar to the original charger; with 45W, charging will be slower or will only be maintained if the equipment is used very demandingly.
- Multiple ports: when loading several devices At the same time, the power is shared; there is usually a faster main port. Evaluate bases with multiple ports
- Use while charging: If you work with heavy apps, some of the energy is consumed in real time, reducing the net battery charge.
Charging speed and standards: PD, PPS and Quick Charge
For laptops, prioritize USB-C PD with profiles of 15 V/3 A, 20 V/3 A or 20 V/5 A (up to 100 W). Some models support PPS (adjustable tension) which improves efficiency. Fast charging standards PPS optimizes power delivery. QC is useful for mobile devices, but It does not replace PD on laptops.
- Fast Input: a power bank with a 2A input or USB-C with PD faster recharge If you use a compatible charger. Charging with a 1A charger will take a long time.
- Avoid PC USB port To refill the power bank: the current is low and the charging time is longer.
Best practices for taking care of your power bank
- Healthy margins: try to keep it between 25% and 80% whenever possible; it's okay if you occasionally go outside that range.
- Storage: If you don't use it, check it and recharge it every 2–3 months to avoid deep discharges.
- Lifecycles: the usual is between 300 and 1.000 cycles, depending on quality and use.
- Quality cables and chargers: Using low-quality accessories can reduce life battery or cause charging failures.
If you're going to buy, consider actual capacity, speed of entry y outputnumber of ports, size/weight and extras such as screen or a flashlight. The price difference compared to basic options makes sense if you really need it. more power o quick entries.
Useful alternative: reverse charging from your mobile phone
Many Androids allow reverse charge: with a USB-C to USB-C cable or wirelessly if the phone supports it. It's ideal for accessories (headphones, watch) or another mobileRemember that it is less efficient wirelessly and it is best not to do it when the mobile phone is below the 20-30%.
Travel by plane with your external battery
Power banks should go in hand luggageMost airlines allow up to 100 Wh No paperwork required. To find out the Wh: convert mAh to Ah and apply Wh = V Ă— AhIf your battery is close to or exceeds 100 Wh, check the company's terms and conditions.
Charging a laptop with a mobile phone's external battery is feasible if you meet two key requirements: The laptop accepts USB-C PD or compatible DC outputand the power bank can deliver the necessary powerBatteries designed for mobile phones often fall short; if your goal is a portable device, invest in a model with high-power PD, a suitable cable, and, if you travel, capacity within the permitted Wh limit.
