Power Supply Help

[DanielJacinto]

Hi. I made a boombox that runs a car head unit powering 2 component speakers and one subwoofer through the use of direct sub out. it runs for about 4 hrs on max volume off the 12v 9ah SLA Battery and can run forever if i connect my car battery charger to the battery terminals and use it like a power supply. I recently purchased a 12v 20a power supply and am having difficulty in figuring out how i can connect the power supply internally in parallel with the battery without damaging the battery.

 

[TLS Guy]

Hi. I made a boombox that runs a car head unit powering 2 component speakers and one subwoofer through the use of direct sub out. it runs for about 4 hrs on max volume off the 12v 9ah SLA Battery and can run forever if i connect my car battery charger to the battery terminals and use it like a power supply. I recently purchased a 12v 20a power supply and am having difficulty in figuring out how i can connect the power supply internally in parallel with the battery without damaging the battery.

First of all a 12 volt power supply will not charge the battery, as there is no driving voltage as the battery is 12 volts. It takes 14 volts to charge a 12 volt battery. However the device has to be regulated in order to not over charge and damage the battery.

I would use a low powered regulated charger like this.

 

[tyhjaarpa]

First of all a 12 volt power supply will not charge the battery, as there is no driving voltage as the battery is 12 volts. It takes 14 volts to charge a 12 volt battery. However the device has to be regulated in order to not over charge and damage the battery.

I would use a low powered regulated charger like this.

I think he wants to connect this power supply as alternative power option to battery so he could use either the battery or power supply.