4 ms·
> 40w @ 5V = 8A > 8A * 1.5hrs = 12,000mAh This assumes the battery is 5V, but lithium-ion batteries are typically counted as 3.6V. 40W / 3.6V = 11.(1) A 120
by rhn_mk1 4y ago
> 40w @ 5V = 8A
> 8A * 1.5hrs = 12,000mAh
This assumes the battery is 5V, but lithium-ion batteries are typically counted as 3.6V.
40W / 3.6V = 11.(1) A
12000mAh / 11.(1)A = 1.08h
Adjust the rest of the calculations accordingly.
- naikrovek 4y ago3.7v but they charge to 4.2v, but it doesn't matter, because the dynamo is going to produce variable voltages and currents. so it's going to go through a boost-buck converter and that will output 4.2v at whatever current it can.
- rhn_mk1 4y agoThe peak voltage of the battery might be 4.2V, but the average will be around 3.6 nevertheless. The voltage before the energy enters the battery doesn't change the calculation of battery capacity (and its time to discharge) anyway. EDIT: now I noticed that the calculation is about charging, rather than discharging. 4.2V makes better sense in that case.