Battery Capacity Converter
Convert between mAh, Ah, Wh, and Joules with runtime estimates
Conversions (at 3.7V)
mAh
5.00K
Ah
5
Wh
18.5
kWh
0.02
Joules
66.60K
Runtime Estimates
Based on 18.5 Wh capacity:
smartphone6.2 hrs
tablet3.7 hrs
laptop37 min
led bulb1.9 hrs
usb fan7.4 hrs
power bank charge3.7 hrs
Battery Equivalents
186501.67 batteries
217001 batteries
aa nimh2 batteries
aaa nimh5 batteries
cr123a3.33 batteries
car battery0.04 batteries
Common Voltages
Common Batteries
Understanding Battery Capacity
mAh (milliamp-hours): How long a battery can supply 1mA. Does not account for voltage.
Wh (watt-hours): True energy capacity. Wh = mAh x V / 1000. Use this to compare different batteries.
C-rate: Charge/discharge rate relative to capacity. 1C for 5 Ah battery = 5A current.
Power bank tip: A "20,000 mAh" power bank at 3.7V is 74Wh. At 5V USB output, it's effectively 14,800mAh due to conversion losses.