Myth or Fact: "A 20,000 mAh power bank charges a 5,000 mAh phone 4 times"
MYTH: mAh is at 3.7 V and losses are ~30–40 % → about 2.5 times.
"A 20,000 mAh power bank charges a 5,000 mAh phone 4 times." Myth or fact? 🔋
❌ MYTH! You'll get about 2.5 full charges.
🔥 WHERE IT GOES: the power bank boosts its 3.7 V cells up to 5 V, the cable has resistance, and your phone's charging chip has losses too. Together, about a third of the energy turns into heat.
🧮 THE REAL MATH:
20,000 mAh × 3.7 V = 74 Wh
74 Wh − ⅓ heat ≈ 48 Wh
A 5,000 mAh phone ≈ 19 Wh
48 ÷ 19 ≈ 2.5 charges ✅
📌 Rule of thumb: expect about two-thirds of the number on the box — and check the Wh on the label.
Read the voiceover (transcript)
- Four charges from twenty thousand?
- Myth! For a five thousand milliamp phone, you'll get about two and a half.
- Boosting to five volts, the cable and your phone's charging chip waste about a third as heat.
- So seventy-four watt-hours become about forty-eight. That's two and a half phone charges!
- Expect about two-thirds!
- Next myth: voltage or current? Follow for more!
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