What is the Voltage and Amperage Rating for Roadmaster Parking Light Diode

Updated 12/15/2014 | Published 12/13/2014

Question:

Hi Im Looking For A Diode to keep the flow in my battery backup circuit for a car stereo one way. I was wondering if this would be able to handle lets say a small 12v 15ah scooter battery powering the memory save on a car stereo. so the amperage would most likely be around 300-500mha at still 12volts while powering only the memory save on the stereo Stereo Off. And A charger would be charging the battery at about 12v 2amps While Stereo Is On BUT it will also have a 40amp 12v ac to dc transformer powering the stereo when its on, and a battery tenderizer when stereo is on to charge battery So it will be a circuit like in the picture. Sorry Its Not to Scale or with correct symbols. Wondering If This Would Work/ Is the circuit Even Feasible like the picture?Your Thoughts? Any Help Is Greatly Appreciated.

asked by: Nick

Helpful Expert Reply:

The diode # RM-690 can handle up to 120 volts at 24 amps so it should work just fine for your needs provided nothing else exceeds 120 volts at 24 amps.

Regarding your picture, most battery chargers or batteries on vehicles say not to ground the charger to the battery being charged so you will want to change that to a chassis ground.

The AC/DC transformer would have to have the proper output voltage and amperage so as not to blow the fuse associated with the stereo.

There needs to be a switching mechanism somewhere. Basically if you had the charger and transformer providing power at the same time it could damage the stereo. Otherwise you would have to unplug one or the other. So you would need some type of transfer switch, similar to what is found on motor homes when they plug into shore power at a camp site.

expert reply by: Michael H