Upgrading battery warning light on 2013 predent.

[phil1944]

I want to upgrade the amber warning light on my 2013 precedent to a meter type indicator to get real time battery status. The amber light only comes on when batteries are low. I would think that the real time switch would have to have a constant flow of power to get reading. How does the new meter hook up to the factory wiring? Also, I need it to work behind the ignition switch. Thanks.