Can I Just Change the Battery?

I learnt sumthin, lol.

I would have guessed a resistor or even a zener diode would work better but a "regular" diode does actually reduce voltage. I tried to find out what a rechargeable 9V battery is recharged at but I couldn't find an exact answer. For an example, a 12V car battery is recharged typically between 13.2 and 14.7 volts. With a diode protecting the 9V battety the 12V should be dropped to around 11.2V I believe. Thank you.

It could come in really handy on aftermarket stereos and alarms that have to be programmed a ton to work satisfactorily. I'm thinking a cigarette lighter/power port with the opposing male end plugged in, a diode in line, and a 9V battery could save a lot of reprogramming headaches with some aftermarket equipment. Everytime I disconnect my trucks battery I "look forward to" rereading a ~100 page manual for the stereo and a ~20 page manual for the alarm just to get it back to what I had before the battery disconnect.

 

So what I've read is, you gotta be so fast that the cable doesnt even recognize that it's been disconnected. Theres special training classes for it

 

They call me Superman, I'm here to rescue you, I'll change your battery so fast the vehicle won't know it's been done, ECU's and presets don't mean jack to me, I've got the degree... lmao.

 

Yes you will lose your radio presets, your trip 1/2 counts and perhaps the ECU learning. So record your radio and trip meters before disconnecting the old battery. The ECU learning will come back in time.
I don't know about the start & immediately stall, but it would not surprise me if this is normal with a disconnect & new battery.

 

The diode would be installed the other way, dropping the 9v battery voltage a bit. The CPU (and other electronics) would have to work with a lower voltage than the 12v battery because it is not unusual for the voltage to drop significantly during starting, so the approximately 9v supply is adequate to maintain the memories. In theory, anyway. I haven't tried it.

 

Power supplied to the cigarette lighter socket or the power port is not going to do it, since they're not live when the key is turned off. I've had my battery disconnected so many times doing electrical work that I don't even worry about it.

Some vehicles are very picky about disconnecting the battery. Windows need to be recalibrated, radio needs the antitheft code put in, etc. Tacoma's are not a problem.

Edit: I just realized that the OP of this post is another one of those MFers that posts a question, immediately logs out and never returns.

 

hmmm, same as my wife

 

"Why the fuck are the batteries taken out of the remote?"

 

Son of a b... why didn't I think of that? I know better too.

It's still Friday!