Is there anyway of making a battery backup for the Radio?so you dont re program it?

[Starscream88]

Im sick of re-programming my radio every bloody time I take the battery out or unhook it for electrical work,

anyone know of a place that sells some kind of battery back up?
Even if it only lasts an hour or two,

OR

Is there a simple way of making one cheap?

 

[ECU5.0]

ive used exactly what you want....although im not real sure where to get one.....its a little harness that goes in your cigarette lighter with a 9 volt battery attached to it....they work really well, i used to use them at work when i changed a battery. id just check at autozone or pep boys

 

[85_SS_302_Coupe]

run a wire from the memory wire on your stereo to a fuze in your fuze box. Make sure it's at least a 15 fuze, and just tuck the end of the wire in with the fuze. Just make sure you turn off the radio when you turn your car off or it'll drain your battery.

 

[Starscream88]

Dont mean to sound stupid but which ones the memory wire?

also will that work?

If I take the battery out the whole car is without power right?

So what good would it be wired to the fusebox?

 

[conartist]

Part# 20309

http://www.wirthco.com/compact.htm


I don't know much about this model, but i have sold the regular with out the bypass to may people in the past... esp to the hot-rod guys, quick on/off

 

[BADPONYsc]

run a wire from the memory wire on your stereo to a fuze in your fuze box. Make sure it's at least a 15 fuze, and just tuck the end of the wire in with the fuze. Just make sure you turn off the radio when you turn your car off or it'll drain your battery.

The radio would still lose power when the battery was disconnected/removed. The entire fusebox will lose power with no battery connected.
I've never heard of doing this, but if you had a battery with side AND top posts, you could run a new wire from the radio's constant power lead, through the firewall, and connect it with a terminal to the unused + side of the battery. Then when the battery was disconnected at the main + terminal, the radio's terminal would still be connected to the other one. This would only work for disconnecting the battery, but not for removing the battery. The only other alternative I can think of would be to put an extra battery in the trunk, get a battery isolator that splits the alternator's charge to both batteries, and connect the radio/amps/etc to the trunk battery. Then, even if you removed the front battery, the radio would still have power from the rear battery.

I can't believe I just suggested that insane idea.

I always just remember where all the settings for the clock and stuff are, so whenever I cut the power I can just quickly reset it. I also set my crossovers, bass boost, and levels on my amp where I don't use the radio's "loudness" button and the bass and treble settings stay in the middle... where they are when the cd player is first powered up. So all I have to set is the clock.
Hope this helps!

 

[Starscream88]

Thats what I thought,

Anyone confirm this?

 

[Michael Yount]

Guys - electricity is funny stuff - it likes to follow any path that's available to it. So, if you provide a circuit to the memory wire so it stays hot with the battery's main terminal disconnected, that hot source will 'back feed' any other circuits that come in contact with the memory wire. So if the memory wire was fed from a hot fuse in the fuse box, that whole circuit will remain hot and anything else attached to it, unless you also install a diode in the memory wire to block the flow of current limiting it only to the radio. And of course if you have to replace the battery, it won't work. I was gonna suggest a 9volt would probably provide enough juice to save the memory settings, and it sounds from the previous post that someone makes something like that that plugs into the cigarette lighter. The beauty of that approach is that it's a very small battery voltage. The whole purpose of disconnecting the battery is so you don't short something out - and with the small battery/voltage keeping your presets alive, you still won't have to worry about a big short/big current frying things while you're working. I'd look for the 9V battery gizmo described above, or make one - wouldn't be difficult to do.

 

[cardudeusa]

ive used exactly what you want....although im not real sure where to get one.....its a little harness that goes in your cigarette lighter with a 9 volt battery attached to it....they work really well, i used to use them at work when i changed a battery. id just check at autozone or pep boys

I use the same thing when I'm at work changing a battery. Work great as long as the cigarette lighter works.

 

[Sam8950]

You can permanently modify your radio wiring per the attached diagram in order to maintain memory with the vehicle battery removed. Added components and wiring are shown in green. Diode D1 keeps the added battery from feeding back into the rest of the vehicle electrical system. Diode D2 protects the added memory retention battery from the vehicle electrical system. (WARNING! BATTERIES CAN EXPLODE WHEN SUBJECTED TO EXTERNAL POWER SOURCES.)

It is best to modify the radio memory hold wire, if your radio has one. Most aftermarket radios are so equipped. I believe most newer (since mid-1980's ? ) auto factory radios also have a separate memory hold wire. Consult your vehicle's wiring manual or after market radio information to make sure. If you can use the separate memory retention wire, the diodes won't have to handle the full radio power requirements.

IMPORTANT: USE ONLY DOIDES THAT ARE RATED FOR YOUR RADIO'S POWER CONSUMPTION NEEDS. DOIDES MUST BE RATED AT LEAST 15 VOLTS AND THE NECESSARY WATTAGE/AMPERAGE FOR YOUR RADIO REQUIREMENTS. This is especially critical if your radio does not have a memory retention wire and it is necessary to modify the radio main power wire.

If you do not have some electronic experience, it would be best to have someone who does, or an audio shop, make this modification.

WARNING. COMPONENTS THAT ARE THE WRONG RATING, OR WHICH ARE INSTALLED INCORRECTLY (DIODE POLARITY IS CRITICAL) CAN FAIL AND CAUSE A FIRE, DAMAGE TO ELECTRICAL EQUIPMENT AND/OR PERSONAL INJURY.

Scared? Well, you should be.

I would also suggest removing the added battery from the circuit when not needed. Good luck.

Memory Hold Diagram

 

[BlackFox5.0]

I saw the 9v cigarette light thing in JC Whitney before.

 

[Camman]

I am by no means a jenious or anything, but could you not just use a capacitor... the keep alive for the radio can not consume that much electricity, and you would just install a diode in front of the capacitor to stop the electricity from flowing back into the system...

 

[Michael Yount]

Great explanation Sam8950 - well done.

 

[Sam8950]

I am by no means a jenious or anything, but could you not just use a capacitor... the keep alive for the radio can not consume that much electricity, and you would just install a diode in front of the capacitor to stop the electricity from flowing back into the system...

That would work if you don't need to disconnect the car battery for more than a few seconds, or a couple of minutes at the most. Of course, it depends on the size of the capacitor and the power needs of the hold circuitry. That's how a VCR holds its memory during a brief power loss, or when you're moving it quickly from one place in the house to another. Most VCR's have a healthy capaciter in the internal power supply. It may be worth a shot, but if you need to buy a capacitor anyway, the two diodes and a small 12v battery are probably a wash in cost.

 

[Sam8950]

Great explanation Sam8950 - well done.

Thanks. I knew that engineering degree would be good for something someday.

 

[wythors]

A Google search of "radio memory saver" came up with this as the first hit. http://www.sjdiscounttools.com/kas295a.html For $8.22 why screw around with rewiring or reengineering your car?

 

[Sam8950]

. . . why screw around with rewiring or reengineering your car?

Because that's why engineers & other geeks like to play with cars.

 

[Trojan Horse]

Ok Techies, tell me if this will work.

This is a diagram of a radio-preset saver that I believe will work. As you can see by the diagram there should be no way that the system can back feed to the battery pack. The “red” line is the memory wire from your fuse box to your radio. The initials N.C. and N.O. stand for “Normally Closed” and “Normally Open”. They refer to the contacts in the relay. The “Normally Open” contacts are energized when power is flowing normally from the fuse box to the radio. The “Normally Closed” contacts would be energized whenever your vehicle’s battery power is removed from the system.

 

[Sam8950]

This is a diagram of a radio-preset saver that I believe will work. As you can see by the diagram there should be no way that the system can back feed to the battery pack. The “red” line is the memory wire from your fuse box to your radio. The initials N.C. and N.O. stand for “Normally Closed” and “Normally Open”. They refer to the contacts in the relay. The “Normally Open” contacts are energized when power is flowing normally from the fuse box to the radio. The “Normally Closed” contacts would be energized whenever your vehicle’s battery power is removed from the system.

That'll work, IF the relay activation time (actually the de-activation, or release, time in this case) is less than the time it takes the radio internal power residual to bleed off to the point where the memory is lost. A solid state relay would be faster, if the speed is needed.