Power Bank Guide: Understanding Capacity, Safety, and Best Practices
In today’s fast-paced digital world, power banks are vital for ensuring your devices stay charged while you’re on the move.
Our featured blog post for today is inspired by the CAAP’s (Civil Aviation Authority of the Philippines) latest ruling about the increasing awareness on carrying dangerous dry goods on flights. That includes the approved hand-carry powerbanks.
In today’s world, who does not bring a power bank even on a short trip to Cebu in the morning and returns before midnight in Manila?
In this blog post, we’d like to educate our readers that it’s crucial to recognize that not all power banks are equal.
To truly benefit from your portable charger and protect your devices, you must understand their capacity, safety features, and optimal usage practices.
We encourage our readers to make informed choices to maximize your charging experience.
Understanding Power Bank Capacity
Power banks come in various capacities, and understanding how to interpret their values can help you choose the right one for your needs.
What Does mAh Mean?
Power bank capacity is typically measured in milliampere-hours (mAh), which indicates how much charge it can store.
A higher mAh rating means the power bank can charge devices multiple times before needing a recharge itself.
For example, if you have a 10,000mAh power bank, it can theoretically charge:
- A 3,000mAh smartphone is about 2-3 times (accounting for energy loss).
- A tablet with a 7,500mAh battery lasts around once before needing a recharge.
How to Choose the Right Capacity?
When selecting a power bank, consider:
Your device’s battery capacity.
Check the mAh rating of your phone, tablet, or laptop.
How often you need to recharge on the go – If you travel frequently, a high-capacity power bank is ideal.
Size and weight – Higher-capacity power banks tend to be bulkier.
And, here’s the suggested general guide:
- 5,000mAh – Best for emergency charging (1 full smartphone charge).
- 10,000mAh – Suitable for daily use (2-3 smartphone charges).
- 20,000mAh – Ideal for multiple devices or tablets.
- 30,000mAh+ – Designed for power users and travelers.
What in the world is 160WH?
Some power banks list their capacity in watt-hours (Wh) instead of mAh. You can convert Wh to mAh using this formula:
mAh = Voltage(V) Wh×1000
Most power banks operate at 3.7V (lithium-ion battery voltage).
For example, if a power bank has a 160Wh capacity, the conversion to mAh is:
mAh= 3.7 160×1000
mAh=43,243mAh So, a 160Wh power bank has approximately 43,243mAh capacity at 3.7V.
But if the output voltage is 5V (USB output), the effective mAh would be lower:
mAh = 5 160×1000
mAh = 32,000mAh So, depending on whether you measure at the battery level (3.7V) or USB output level (5V), a 160Wh power bank can range from 32,000mAh to 43,243mAh.
Therefore, a 160Wh power bank is a super-duper huge power bank already.
It can already be a portable power station, like the Ecoflow River 2, which is half the size of 160wh.
How Efficient Are Power Banks?
Due to energy loss during conversion, power banks do not provide 100% of their stored energy. Most power banks operate at an efficiency of 70-90%.
This means a 10,000mAh power bank effectively delivers approximately 7,000-9,000mAh to your device.
Best Practices
Best Practices for Power Banks
Following proper usage and maintenance practices ensures your power bank remains efficient, safe, and long-lasting. Below are the best practices to maximize its performance and lifespan.
- Charging Your Power Bank Correctly
✅ Use the Right Charger and Cable
Always use a compatible charger that matches the power bank’s input requirements (e.g., 5V/2A, 9V/2A for fast charging).
Use a high-quality USB-C or micro-USB cable to prevent slow charging and inefficiencies.
✅ Charge Your Power Bank Regularly
If you do not use your power bank frequently, recharge it at least once every 2-3 months to prevent battery degradation.
Avoid completely draining the power bank before recharging, as deep discharges can shorten battery life.
❌ Avoid Overcharging
Most modern power banks have overcharge protection, but it is still advisable to unplug once fully charged.
Leaving it plugged in overnight occasionally is fine, but frequent overcharging may reduce its lifespan. - Proper Usage to Extend Battery Life
✅ Charge Devices Within Recommended Limits
Avoid draining your power bank to 0% frequently. For optimal battery health, try to keep the charge between 20% and 80%.
Please do not use a power bank while charging, as this can cause overheating.
✅ Match the Power Output to Your Device
If your smartphone supports fast charging, ensure your power bank has Quick Charge (QC) or Power Delivery (PD) technology.
Using a lower-wattage power bank for high-power devices (like laptops) may lead to inefficiencies and slower charging speeds.
❌ Do Not Charge Multiple Devices at Once (If Avoidable)
While many power banks support multi-device charging, doing so reduces efficiency and increases heat buildup.
If charging multiple devices is necessary, use a power bank with high output power (e.g., 18W, 30W, or 65W for laptops). - Safety Precautions When Using a Power Bank
✅ Store in a Cool, Dry Place
Keep your power bank away from direct sunlight, heaters, or extreme cold.
Ideal storage temperatures range between 10°C – 35°C (50°F – 95°F).
✅ Use Power Banks with Certified Safety Standards
Look for certifications such as:
✔ CE (Conformité Européenne) – Meets European safety standards.
✔ FCC (Federal Communications Commission) – Approved for US electronic safety.
✔ RoHS (Restriction of Hazardous Substances) – Ensures no harmful chemicals.
✔ UL (Underwriters Laboratories) – Verified safe against fire and electrical hazards.
❌ Avoid Cheap, Unbranded Power Banks
Low-quality power banks may overheat, catch fire, or explode due to poor battery management systems.
Choose reputable brands like Anker, Xiaomi, RAVPower, Baseus, or Samsung for safety assurance.
❌ Do Not Use a Damaged Power Bank
If your power bank is swollen, leaking, or overheating, stop using it immediately.
Dispose of it properly at an electronic waste recycling center to prevent hazards.
- Traveling with a Power Bank
✅ Follow Airline Regulations
Power banks must be carried in carry-on luggage (not checked baggage).
Most airlines restrict power banks over 100Wh (27,000mAh @ 3.7V) without approval.
If you need a 160Wh power bank (43,000mAh @ 3.7V), check with the airline before your flight.
✅ Turn Off the Power Bank When Not in Use
Some power banks have auto shut-off, but if yours does not, manually turn it off when not needed to save power. - When to Replace Your Power Bank
Over time, power banks lose efficiency. Consider replacing your power bank if:
❌ It no longer holds a charge for long.
❌ It gets excessively hot while charging or in use.
❌ It has physical damage (swelling, leaking, or cracked casing).
❌ It takes too long to charge devices, even with proper cables.
