A 2600 mAh power bank usually gives roughly half to one phone charge or 1–2.5 hours at 5 V depending on load and efficiency.
Small packs in the 2,600 mAh range were the pocket chargers that kicked off the power-on-the-go era. If you still own one, you might wonder what it can do today with bigger phones and wearables. This guide gives clear math, practical run-time ranges, and easy rules so you can predict how long a 2,600 mAh unit will keep a device alive.
Quick Math That Explains Runtime
Internal cells in these packs are single lithium-ion units at around 3.7 V nominal. Energy lives in watt-hours (Wh), not just milliamp-hours (mAh). To compare across devices and cables, convert the label to Wh with a simple formula: Wh = (mAh × V) ÷ 1000. That turns 2,600 mAh at 3.7 V into about 9.6 Wh. The output port delivers 5 V, and the boost converter wastes some energy, so the usable energy that reaches your device is lower than the raw 9.6 Wh.
| Step | What It Means | Typical Value |
|---|---|---|
| Cell Energy (Wh) | Convert 3.7 V cell rating to Wh | 2,600 × 3.7 ÷ 1000 ≈ 9.6 Wh |
| Conversion Loss | Boost to 5 V and heat/cable loss | ~25–40% lost (efficiency ~60–75%) |
| Usable Output (Wh) | Energy that actually reaches the device | ~5.8–7.2 Wh |
| Phone Recharge Share | Portion of a modern 4,500–5,000 mAh phone | ~45–70% of a full charge |
| Low-Draw Gadget Time | Earbuds case, small GPS tracker (0.5 W) | ~11–14 hours |
| Medium Draw Time | 5 V, 0.5 A accessories (≈2.5 W) | ~2.3–2.9 hours |
| High Draw Time | 5 V, 1 A loads (≈5 W) | ~1.2–1.4 hours |
2600 mAh Power Bank Runtime — Real-World Cases
The numbers above translate cleanly into daily use. Pick the case that matches your device and load to set expectations before you head out.
Modern Smartphone Top-Up
Many phones ship with 4,500–5,000 mAh internal batteries. Feeding them from a 2,600 mAh pack gives a partial refill in the 45–70% range, shaped by cable quality, converter efficiency, and how much you use the phone while charging. If the screen stays off and you let it sip at 5 V, 1–1.5 A, you’ll land near the higher end. Using GPS or a hotspot during the charge can cut that by a third.
Older Or Compact Phones
Devices with 2,000–3,000 mAh packs (many small handsets and budget models) can reach near-full from empty, or a solid 70–100% top-up. Expect fewer minutes if the phone draws aggressively for gaming or camera use during the session.
Earbuds, Watches, And Trackers
These tiny loads draw fractions of a watt. A 2,600 mAh stick can recharge an earbuds case multiple times or run a GPS tracker overnight with margin. The table shows why: at 0.5 W, ~12–14 hours of output is on the table because the boost converter wastes less under light load and heat stays in check.
USB Accessories And LED Lights
Think clip-on fans, selfie lights, or 5 V LED strips. A 0.5 A device (about 2.5 W) usually runs for around 2.5 hours. A full 1 A load doubles the wattage and roughly halves time, landing near 1.3 hours, give or take.
Why A 2,600 mAh Label Does Not Equal 2,600 mAh At 5 V
The mAh printed on the case refers to the 3.7 V cell inside, not the 5 V USB port. The pack must step voltage up, and every step eats a slice of energy. Real devices also waste a bit in their own charging circuits. It helps to think in Wh end-to-end instead of mAh at the port.
Voltage And Conversion
The cell sits near 3.6–3.7 V for a large part of the discharge. The output needs 5 V. A boost converter bridges that gap and usually returns something between about 60% and 90% efficiency depending on design and load. Cheap sticks land low; premium designs land high.
Heat, Cable, And Device Overhead
Loss shows up as warmth in the pack and cable. Thin or long cables drop voltage and waste power. Phones add their own overhead to manage the battery safely, so the charge you see on-screen is always a bit less than the raw energy you fed in.
How To Estimate Hours For Any 2,600 mAh Pack
Here’s a simple, repeatable process. You only need the device power in watts (W) or its current draw at 5 V.
Step 1: Convert To Watt-Hours
Multiply the label by 3.7 V and divide by 1000. For 2,600 mAh you get ~9.6 Wh.
Step 2: Apply Realistic Efficiency
Use 60–75% for a pocket stick unless the maker quotes a tested number. That gives ~5.8–7.2 Wh at the port.
Step 3: Divide By Device Power
If your gadget draws 2.5 W, divide 5.8–7.2 Wh by 2.5 W to get about 2.3–2.9 hours. At 5 W, expect about 1.2–1.4 hours.
Factors That Move The Needle
Real-world time never lands on one exact number. These are the variables that matter and what to do about each.
Temperature
Cold slows lithium cells; heat ages them and raises losses (discharging at low temperatures). Keep the pack in a jacket pocket in winter and out of direct sun in summer to protect both runtime and long-term health.
Age And Cycle Count
Cells lose capacity with months and charge cycles. A stick that lived in a hot car will deliver less energy than a new one. If your old pack stalls early, that’s the reason.
Charge Rate
Fast output looks handy but boosts losses, especially on tiny packs. A steady 1 A at 5 V usually returns better net watt-hours than pushing 2 A on a 2,600 mAh unit.
Cable Quality
Short, thick cables waste less and help the device stay at a higher voltage under load. If the phone keeps dropping in and out of fast-charge, swap the cable first.
When A Small Stick Still Shines
There’s a reason these compact tubes remain useful. They’re light, easy to pocket, and perfect for a night out, a commute, or a backup in a sling bag. Pair one with a phone at 15–30% and you can finish a day without hunting for a wall plug.
Good Sources For The Numbers
Two rules anchor the math you saw here: 3.6–3.7 V is the typical lithium-ion cell voltage used in these packs, and the energy conversion is Wh = (mAh × V) ÷ 1000. You can check both with reliable references: see the nominal cell voltage and Goal Zero’s note on the mAh → Wh formula.
Ways To Stretch Runtime From A Tiny Pack
Use these habits to squeeze more minutes out of a charge session when you only have a small stick in your pocket.
| Tactic | Why It Helps | Typical Gain |
|---|---|---|
| Charge Screen-Off | Lower device draw during charging | +15–30% time |
| Use A Short, Thick Cable | Less voltage drop and heat | +5–10% |
| Skip 2 A On Tiny Packs | Lower converter losses at modest current | +5–15% |
| Keep It Warm In Winter | Cold reduces available capacity | +10–20% in cold |
| Top Up At 20–40% | Charging is more efficient mid-range | Small but useful gain |
Bottom Line That Helps You Plan
A 2,600 mAh stick holds roughly 9.6 Wh on paper and delivers around two-thirds of that to your device. In practice that means a partial phone refill, a few hours for small 5 V gear, or many cycles for tiny wearables. Use the simple steps in this guide to plug in your own device draw and you’ll forecast time within a tight band before you leave the house.