Currently, I am thinking a Kit of all the needed parts would be ABOUT $150 or so, plus shipping (and tax in CA, I assume).
I MIGHT build some for ABOUT $250 (plus S and T), but I am not sure how my stamina will hold out. The "fussy" part is getting the slot for the Display just right. The wiring is not bad, and some parts are even optional. Required are 12 solder connections, with another 9 optional (on two toggle switches).
BUT, it IS possible to do things wrong, and "blow" some of these parts, the circuit board or the Display, or even your car! Try this ENTIRELY at your OWN RISK.
Maybe somebody in your area will build the SOC-Meter for you.
As we discover more things to display, the SOC-Meter, with upgraded software, will be able to show more than just SOC. Right now, my version 1.05 shows "SOC Percentage" (of 281 raw), and the "Raw SOC".
IMPORTANT NOTE: We do NOT know that this "SOC" number observed on the EV-CAN buss is actually useful for any specific purpose, and it MIGHT not be SOC at all!
Note: The same device, with the addition of an RS232 connection to a PC (RS232-to-USB for most folks), can be used for one-channel CAN-Capture.
See SOC/GID-Meter and CAN-Do Info
2010 Prius, now for sale
2011 LEAF, sold in 2015
2018 Tesla Model 3
2014 Tesla S, Model 3 in 2019
Solar PV: 33 x 225W -> 7 kW max AC
To Sell: X-treme 5000Li EV motorcycle