simple state of charge meter

[dcb]

was looking at simple analog meters for the scooter project and saw this, thought it was kinda cool.
Simple EV Charge Control

Dual movement meter, compares pack voltage to current, if where the lines cross is green then you are ok. Yellow, head towards a charging place. Below 20% is red, cell reversal risk.

[Daox]

Pretty neat.

[Old Tele man]

...hams and power meters use similar "dual / crossing" meters; hams for SWR and PWR, power meters for AMPS and VOLTS, and simultaneously to show WATTS.

...might be a "source" of usable parts?