diff --git a/README.md b/README.md index 75d8c7a24dfbd9b5b5e8887d779c725a58000226..e291da97b2beca1e4ba81fc092be7b945316253f 100644 --- a/README.md +++ b/README.md @@ -22,9 +22,18 @@ The nRF52832 draws 5mA peak @ 3.3V The Hall Effect Sensor draws xmA @ 3.3V -Assume whole device runs at peak load for 10% of the time +Assume whole device runs at peak load for 5% of the time -

\$\$ P = IV = 5e-3 * 3.3 * 0.1 = 1.65mW \$\$

+P = IV = 5e-3 * 3.3 * 0.05 = 0.825 mW +1 Wh = 1 watt for 1 hour +0.825 mW for 365 days = 7.2 Wh +E [wh] = (Q [mAh] * V [V])/1000 +Q = (1000 * 7.2)/3.3 = 2181 mAh + +The CR2477 is one of the largest coin cell batterys (20mm diameter and 4.7mm thickness) and has a capacity of ~1000 mAh. +An Alkaline AA battery can supply 1.5V with a capacity of 1800–2600 mAh + +(Haven't found a good way to embed maths equations in the README and have them render in the Project page of the repo, there's http://www.sciweavers.org/free-online-latex-equation-editor and http://latex.codecogs.com/ but they require editing the equation through their website.)