A 5,000 mAh power bank usually delivers ~2,600–3,100 mAh at 5V, enough for about 0.6–1 full phone charge, depending on your device and settings.
If you bought a compact 5,000 mAh pack and want to know how far it goes, here’s the straight answer with math, real-world loss factors, and simple rules you can use in seconds. You’ll see what that capacity means in watt-hours, how much of it you can actually use, and how many charges or hours of runtime you can expect for common devices.
How Long A 5,000 mAh Power Bank Lasts: Real Numbers
Manufacturers rate most power banks in milliamp-hours (mAh) at the battery’s internal cell voltage, which is around 3.6–3.7 volts for lithium-ion. To compare across devices and estimate runtime, convert to watt-hours (Wh) using the standard formula: Wh = (mAh × V) ÷ 1000. That turns 5,000 mAh at 3.7V into about 18.5 Wh of stored energy. In practice, you won’t get all of that at the USB output because the pack has to boost voltage and manage heat.
Industry guidance and brand support pages point to typical usable output in the 60–70% range once conversion and heat loss are accounted for. That means a pocket-size 5,000 mAh pack often yields 11–13 Wh you can actually push into a phone at 5V. Brands also explain why the “rated capacity at 5V” shown on some boxes is lower than the cell capacity — it reflects those conversion steps. For deeper background on the math and voltage ratings, see Battery University’s voltage explainer and Anker’s note on usable capacity.
Quick Outcomes For A 5,000 mAh Pack
Use this as a fast yardstick. Values are realistic, not lab-perfect.
| Scenario | Usable Output (Typical) | What You Get |
|---|---|---|
| Charging phones with ~3,000 mAh batteries | ~2,600–3,100 mAh @ 5V (≈11–13 Wh) | ~0.9–1.1 full charge (screen mostly off) |
| Charging phones with ~4,000 mAh batteries | ~2,600–3,100 mAh @ 5V | ~0.6–0.8 of a full charge |
| Charging earbuds, watches, fitness bands | ~2,600–3,100 mAh @ 5V | Multiple recharges (tiny batteries) |
| Direct device runtime at ~5 watts draw | ~11–13 Wh | ~2.2–2.6 hours of power |
| Direct device runtime at ~10 watts draw | ~11–13 Wh | ~1.1–1.3 hours of power |
Why The Usable Capacity Is Smaller Than The Label
Two steps reduce what reaches your phone:
- Voltage boost from ~3.7V to 5V (or higher for USB-C PD). The boost circuit consumes energy. Many brands estimate total pack-to-phone efficiency in the 60–70% range for small packs. Anker’s support docs describe this as normal behavior across brands.
- Heat and cable losses. Higher current raises heat in both the pack and cable. Thin or long cables waste more energy, trimming what arrives at the device.
Some makers list a “rated capacity” at 5V that’s already lower than the internal cell figure. Xiaomi’s documentation for larger packs shows this clearly — the 3.7V cell capacity converts to a smaller 5V rated capacity once conversion is factored in.
mAh To Wh: The Simple Conversion You’ll Use Often
When you want hours of device use, watt-hours make life easier. Here’s the one-line rule: Wh = (mAh × V) ÷ 1000. For the common 3.7V figure inside lithium-ion power banks, a 5,000 mAh pack stores roughly 18.5 Wh. If a gadget draws 5 watts on average, divide 18.5 Wh by 5 W for a lab-perfect 3.7 hours. Then trim for real-world loss and you’re in the 2.2–2.6 hour band.
If your charger and phone negotiate USB-C Power Delivery at higher voltages, that affects charging speed, not the stored energy. USB-IF’s spec allows a wide range of power levels (from phone-friendly profiles to laptop-grade). The energy in the pack stays the same; faster flow just means the charge finishes sooner. For an official overview, see USB-IF’s USB Power Delivery page.
How Many Phone Charges Can A 5,000 mAh Pack Provide?
Use this shortcut without a calculator:
- Step 1: Think of a 5,000 mAh pack as roughly 3,700 mAh at 5V before losses (that’s 3.7V/5V scaling).
- Step 2: Apply a real-world efficiency factor of ~0.7–0.85 depending on quality, heat, and cable. Small, slim packs tend to sit nearer the lower end.
That puts the usable 5V output in the neighborhood of ~2,600–3,100 mAh. Compare that to your phone’s battery size:
- Phones around 3,000 mAh: about a full charge if the screen stays off while charging.
- Phones around 4,000 mAh: ~60–80% of a charge.
- Phones around 5,000 mAh: ~50–60% of a charge.
Charging while using the phone drops these numbers since the device burns power and fills at the same time.
Runtime Estimates For Tablets, Cams, And Accessories
Tablets pull more power and drain a small pack quickly. Cameras and action cams often sip power, so the same pack goes further. Wireless earbuds and watches charge many times because their batteries are tiny. The principle is the same: divide usable watt-hours by the device’s average watts, then adjust for real-world loss during charging.
Speed Myths: Faster Charging Doesn’t Create More Energy
USB-C PD can push higher voltage and current to speed up charging, but the stored energy in the pack is fixed. A fast pipe fills the tank sooner; it doesn’t make the tank bigger. If your phone supports higher power levels, you’ll finish earlier, but you won’t squeeze extra watt-hours from the same 5,000 mAh pack.
When PD Helps With Small Packs
Shorter charge time can be handy when you’re hopping between outlets. Just pair a pack and cable that both support your phone’s best profile and keep cable length reasonable. USB-IF lists PD up to very high power levels for larger devices; your phone will negotiate only what it needs.
Charging Time And Runtime Cheatsheet
These are ballpark figures for a 5,000 mAh pack under common power levels. Your phone will throttle near full and adjust based on temperature, so expect a spread.
| Power Level | What It Means | Time Impact With 5,000 mAh Pack |
|---|---|---|
| 5V/2A (≈10W) | Standard USB-A | Phone refill ~1–2 hours for smaller batteries; pack empties in ~1.1–1.3 hours of continuous 10W output |
| 9V/2A (≈18W PD) | Common fast-charge profile | Faster top-ups for mid-range phones; same total energy delivered, just quicker |
| 15V/3A (≈45W PD) | Tablet/ultrabook territory | Small pack drains quickly at high draw; not suited for long laptop sessions |
Real-World Factors That Change Your Result
Cable Quality And Length
High-resistance cables waste power and slow charging. Use short, well-made cables rated for the power level you plan to draw. Frayed connectors or cheap leads can knock a surprising chunk off usable output.
Battery Health And Temperature
Cold weather dulls both the pack and device. Hot conditions trigger thermal limits. Either way, the phone changes how fast it will accept power and where it stops, which shifts your “charges per pack.”
Screen-On Charging
Gaming, GPS, and video streaming keep the device drawing several watts while it charges. The pack is fighting to fill the phone while the phone drains itself, which shortens the number of full charges you’ll see.
Worked Examples You Can Copy
Estimate Full Charges For A 4,000 mAh Phone
Usable from the pack: ~2,600–3,100 mAh at 5V. Divide by 4,000 mAh → around 0.65–0.78 of a charge if the screen stays off. If you keep the phone active during the session, expect numbers closer to the lower end.
Estimate Hours Of Power For A Streaming Stick Or Camera
Assume a 5W draw. Usable energy: ~11–13 Wh. Runtime: 11–13 Wh ÷ 5W → ~2.2–2.6 hours. If the device draws 3W, you’re closer to ~3.7–4.3 hours.
How To Pick A Better 5,000 mAh Pack
Look For A Clear Rated Capacity At 5V
Some boxes print two numbers: cell capacity at ~3.7V and rated output at 5V. The second figure is the practical one. For reference, Xiaomi’s specs on larger packs show rated capacity near 65% of cell capacity once conversion is considered, which lines up with typical real-world results.
Mind The Output Specs And Protocols
If your phone supports USB-C PD or similar fast-charge standards, match the pack’s output to the highest profile your phone accepts. Faster sessions mean less time tethered, even though the energy budget doesn’t change. The official USB-IF overview lists the supported power levels and how negotiation works between charger and device.
Prefer Quality Cells And Controllers
Small packs vary widely in efficiency. Better cells and safer controllers waste less energy as heat and hold up better over cycles. Check user reviews for efficiency notes and real charge counts, not just peak wattage claims.
FAQ-Style Clarity Without The FAQ Block
Does Wireless Charging Change The Math?
Yes — it adds more loss. Coil alignment and heat trim the usable output further, so expect fewer charges than with a cable. For small packs, wired wins on efficiency.
Can A Tiny Pack Run A Laptop?
It can trigger a PD handshake, but the energy reserve is small. A laptop can sip for a short burst, then the pack is empty. Use the pack for phones and accessories instead.
Is A 5,000 mAh Pack Enough For A Weekend Day Trip?
For light phone use with one wired top-up, yes. For heavy camera and maps usage, pick a 10,000 mAh class pack to avoid dipping back to the wall.
Sources And Methods (Brief)
Conversions use the standard Wh = (mAh × V) ÷ 1000 at a 3.7V nominal cell voltage as covered by Battery University. Typical pack-to-device efficiency and the concept of lower 5V “rated capacity” are documented in brand support materials such as Anker’s rated-capacity note and Xiaomi’s FAQ showing 3.7V cell capacity vs. 5V rated output. For charging speed context and official capability ranges, see USB-IF’s USB Power Delivery page.
Bottom Line Numbers You Can Trust
Think of a compact 5,000 mAh pack as ~11–13 Wh of usable energy for phones and small gadgets. That usually translates to ~2,600–3,100 mAh at 5V delivered after conversion losses, or about one full phone charge for smaller batteries and ~60–80% for larger ones. If you need more headroom, step up one size. If you want speed, match your phone’s fast-charge protocol and keep a short, decent cable in your bag.