What Does 10,000 mAh & 100 Wh Mean?
Calculate whether your powerbank is legally allowed on commercial flights, decode battery codes like 18650 and CCA, and understand battery health versus charge percentage.
Is My Powerbank Allowed on the Airplane?
FAA and international airlines cap carry-on batteries at 100 Watt-hours (Wh). Enter your powerbank mAh below:
Under the 100 Wh limit. You can carry this in your cabin carry-on bag with zero restrictions.
Milliampere-Hour (Electric Charge Capacity)
Powerbanks & PhonesA 10,000 mAh powerbank can theoretically deliver 10,000 milliamps (10 Amps) of power for 1 hour, or 1,000 milliamps for 10 hours. However, due to standard 5V voltage step-up conversion and heat loss, effective real-world capacity is approximately 65%–70% of the advertised label (e.g., a 10,000 mAh bank charges a 3,300 mAh iPhone around 2 to 2.2 times).
TSA & FAA Maximum Airplane Carry-on Limit
Powerbanks & PhonesFormula: Wh = (mAh × Voltage) / 1000. Because lithium powerbank internal cells run at 3.7 Volts, a 27,000 mAh bank equals 99.9 Wh — precisely engineered to stay under the 100 Wh global aviation limit! Never pack powerbanks in checked luggage under the plane, as lithium thermal runaway fires cannot be fought in cargo holds.
Cylindrical Lithium Battery Dimensions
Battery ChemistryAn "18650" cell is 18 mm in diameter, 65.0 mm long, and cylindrical (0). A "21700" cell (used in Tesla Model 3/Y and modern high-end flashlights) is 21 mm in diameter and 70.0 mm long, holding up to 50% more energy.
Cold Cranking Amps (Car Batteries)
Car & Heavy BatteriesEngine oil becomes thick like honey in freezing winter temperatures. High CCA (e.g. 700+ CCA) guarantees your starter motor has sufficient explosive electrical torque to crank over a frozen engine block.
Lithium Iron Phosphate (LFP Chemistry)
Battery ChemistryStandard Lithium-ion (NMC) degrades after 500 charges and can burn fiercely if punctured. LiFePO4 replaces cobalt with iron phosphate: it lasts over 10 years of daily charging, tolerates 100% daily full charge without damage, and cannot catch fire even when spiked with a nail.
Maximum Capacity vs Current Charge Level
Powerbanks & PhonesOn iPhone and Android, "100% Charge" means your battery is full for today. "82% Battery Health" means chemical degradation has reduced your battery's maximum gas tank: when full, it holds only 82% of the energy it held on day one.
Ampere-Hour (Car & Marine Deep Cycle)
Car & Heavy BatteriesCommon on RV campers, solar storage, and European car batteries. A 70Ah battery supplies 3.5 Amps of continuous current for 20 hours at 12 Volts.