![Sparked Innovations Dual Battery Voltmeter Monitor 12VDC for Main and AUX Battery - Audio APEX store Sparked Innovations Dual Battery Voltmeter Monitor 12VDC for Main and AUX Battery - Audio APEX store](https://cdn11.bigcommerce.com/s-k1hgnxa/images/stencil/1280x1280/products/792/7945/Dual-Voltmeter-illuminated-disassembled-angle-5-COLORS-Sparked-Innovations-1__20407.1676560034.jpg?c=2)
Sparked Innovations Dual Battery Voltmeter Monitor 12VDC for Main and AUX Battery - Audio APEX store
![Is this a good how to, on adding a second battery? I see some people don't use the relay and some do. Also how do I determine a good second battery to Is this a good how to, on adding a second battery? I see some people don't use the relay and some do. Also how do I determine a good second battery to](https://external-preview.redd.it/2M389S7B3gIhgHt3qixP13bQqSC9sL96N3lvnKPa2t4.jpg?format=pjpg&auto=webp&s=7b9e7fe22818224a348c6fba20f160099ceeec28)
Is this a good how to, on adding a second battery? I see some people don't use the relay and some do. Also how do I determine a good second battery to
![Dual Battery Setups! Let's see them! Multiple Batteries Thread! | Dual battery setup, Car audio installation, Car audio systems Dual Battery Setups! Let's see them! Multiple Batteries Thread! | Dual battery setup, Car audio installation, Car audio systems](https://i.pinimg.com/originals/52/b8/a4/52b8a4e9bf0914d7497b41550a652f81.jpg)
Dual Battery Setups! Let's see them! Multiple Batteries Thread! | Dual battery setup, Car audio installation, Car audio systems
![How to install a dual battery system in a vehicle? National Luna and Deltec Energy Solutions look through this… | Dual battery setup, Car battery, Car audio battery How to install a dual battery system in a vehicle? National Luna and Deltec Energy Solutions look through this… | Dual battery setup, Car battery, Car audio battery](https://i.pinimg.com/originals/6c/5e/92/6c5e9252c8c18c1a52ab20aebec21350.jpg)
How to install a dual battery system in a vehicle? National Luna and Deltec Energy Solutions look through this… | Dual battery setup, Car battery, Car audio battery
![Amazon.com: Dual Battery Isolator Kit 12 Volt 140 Amp Voltage Sensitive Relay Complete VSR Double Battery Automatic Charger : Automotive Amazon.com: Dual Battery Isolator Kit 12 Volt 140 Amp Voltage Sensitive Relay Complete VSR Double Battery Automatic Charger : Automotive](https://m.media-amazon.com/images/I/71b8XPgQ7ML.jpg)