Battery powered memory mod for a car stereo ? ? ?

[curlyjo]

Hi. Does anybody know if there is a simple mod that can keep the memory powered in a car stereo? I drive truck and have a cool slip seat box with a CB and a Kenwood stereo in it. The Kenwood memory is lost whenever the power is disconnected. Can I buy a 9v or AA battery holder from Radio Shack or somewhere? Wire it in and be able to keep the presets every time I take it out. Will it work? Has anyone done this before? Thanks Curly. Four Nine Zero. So. CA.

 

[Grinder74]

Their is a device(battery) available at part stores that plugs into the cigarette lighter

 

[Watergate]

Modern car stereos draw the bulk of their current off of the memory wire, the battery lead. They use the switched lead as nothing more than a signal to turn the radio on. I would think however that the memory alone would draw a minute amount of amps.

The problem you will face is switching between the trucks power supply and the backup battery without loosing your memory.

8 AA batteries would give you the 12 volts needed. I'm sure rat shack has a carrier for 8 AAs. You would have to figure something out to switch it over from the truck to the batteries. Considering the plug in to the cigarette lighter device that's commercially available, you ought to be able to power the memory for a long time with 8 AA batteries.

Now is where the electronic gurus come in with a capacitor on the battery lead that will hold the charge long enough to switch over to the AAs

 

[Lil'Yeshua]

Mine has a separate memory wire. You could wire it as a separate circuit. A nine volt battery might not have the capacity to keep the memory for long. C or D cell batteries could be the deal to do. You might could wire it so that when you plug the box into vehicle power,the vehicle's power could power the memory. Add some diodes at critical points to keep from blowing up the batteries on the memory pack,diodes to keep current from flowing from the batteries positive terminal to the vehicle's power wire for the radio. Remember that electron flow goes from the negative to positive. It I'm wrong then feel free to correct me on this.

 

[curlyjo]

Thanks for the input. My slip seat box is powered by a lighter plug. Also have a extension so I can run it to the CB pwr Post in a big truck. Presets work as long as the box is plugged into a pwr source. 73"s