Wireless Battery Management System? I'm looking for a device to transmit the voltage of each individual battery?

I'm converting my 68 VW Bug to an EV. I'm using twelve Trojan 1275 12v batteries for a total system voltage of 144 volts. I'm looking for a wireless device that can transmit the voltage of each battery to an onboard laptop. I would of course use 12 of them so I can manage each battery. I'll then write an app to display an integrated volt meter on the laptop. I'm designing the Bug to have plenty of get-up and go but the trade off of course is lower range. I want to be able to monitor my usage to eek out the greatest possible range while monitoring my overall usage. In addition by monitoring each battery I can isolate and identify poorly performing batteries. I saw such a device advertised on the homepage of Instructables a couple of months ago. I wasn't thinking ahead and didn't take sufficient note of what I saw.