Hard Wiring Garage Door Opener (12v)

[NoxiousFumes]

Hello all, first post. I figured it best to ask before I start soldering onto things which aren't cheaply replaced. My old garage door opener has always had problems at the point where the internal battery connects to the "posts" if you will. After several disassembles and wedging various washers and other pieces of metal in there I've decided it's time for a permanent fix.

I'm likely just going to throw the internals into some generic "project box" as I'm tired of looking at the garage door opener housing which I've smashed against various surfaces numerous times trying to get the door open. Regardless, upon last disassembly I noticed this thing takes a Duracell MN21/23 (12V). By the way I've tried replacing the battery before, it's not the issue but the battery leads.

I've hardwired several radar detectors into several vehicles in the past, with in-lines fuses, without any issue so I don't see why this should be much different.

Is there any reason I can't "borrow" 12V from say the dome light and hardwire my garage door opener to the car battery? 12V is 12V, and, correct me if I'm wrong, if the car's battery is providing more amperage than needed this isn't an issue as the door opener will only use what it needs.

What's the consensus on this? I'd like to know if you all think I'll fry this thing before I begin re/assembly. It drives me absolutely insane having to hold the "garage open" button while smashing the opener against every surface in my car trying to get it's battery to connect. I've broken the thing more than a few times.

Any input or better ideas are appreciated.

I'll include some pics of the opener in question and the mods I've previously done, which while short lived, did increase functionality most of the time albeit temporarily.

The opener in question. Certain parts of the case have been reinforced with super glue after bashing the entire thing on the emergency brake several times.

Foam used to ensure button was being pressed as well as assist in battery connection.

The battery terminals appear dirty - don't let this deceive you. I've cleaned them several times and used various items - from washers to pieces of Coke can to ensure a strong connection.

My plan:

So can somebody tell me will this or will this not work?

Thanks.

Edit: Mods feel free to move this to the appropriate forum if it's not already there, but please don't delete.

 

[BobK]

It looks to me like the battery contacts are somewhat corroded. Try using some sandpaper on them until they are shiny at the point of contact to the battery.

That said. You problem might not be the battery at all, but the switch. Have you tried operating it with the case open and pressing your fingers against the battery contacts? Does the switch then operate it consistantly? If not, I would suspect the switch.

Connecting the battery terminals to the car battery would probably be okay, but when a car is running it is actually putting out more like 14V which might be too high for the transmitter.

Bob

 

[duke37]

I gather that you are in the USA.
The transmitter can run on 12V from any source, however, car electrics are not just 12V. They have large variations due to switching large inductances. The spikes could well kill the transmitter.
I suggest that you buy or make a battery holder to get good contacts. Make sure the polarity is correct.

 

[NoxiousFumes]

I've cleaned the contacts before but eventually they got corroded-looking again. I'll check the switch and try fabricating something for the battery to sit in and connect to and post the results back here.

Thanks for the input, I'll let you know how it turns out.

 

[Resqueline]

Those switches may become oxidised inside. Check resistance with ohm-meter when pushing (no battery). Also check solder points (for coming loose).