Changing Battery

I am still using the original battery in my 07. I know the end is near so I want to change it in my driveway instead of getting towed etc. I'm interested in retaining the computer's memory so my plan is to connect jumper cables from my car's positive and ground to the trucks positive and ground then remove the truck's battery and replace it with the new battery, remove the cables and put the tools away. Will this work and be safe? When I was twelve years old I had a car battery explode right in front of me so I know first hand how dangerous they can be. I'm trying to do this on the cheap but would pay for a special tool if this method is too risky.

 

Make a double ended jumper to connect your 2 vehicles together via the 12v accessory outlet, turn the car to the accessory setting and the truck to "ON" but not started. make sure all interior lights in the truck are turned off. Remove the 12v lead on the truck battery and insulate it (wrap some plastic around it and tape it up. Remove the ground connection, replace the battery. Ensure the new battery is fully charged, todays alternators normally are not heavy enough to charge a near dead battery, it's not just the current but the duration of the charge that can fry an alternator). Reconnect the ground then the 12v lead. Removed the inter-vehicle jumper, turn off both vehicles and your done.

 

Thanks for the reply. Sounds like a safer alternative. Have you done it this way? Just want to make sure cause I'd rather lose the memory than fry something expensive on one or both vehicles.

 

Just get one of those 9v battery connections that plugs into the cigarette lighter. They only cost a couple bucks.

 

How about the Acc position?

 

Why not just leave the engine running?

 

There is no benefit in doing it this way, just change the battery with the vehicle off.

 

OP
Unless your computer has Death Star schematics in memory, it's easier and safer to just swap batteries, and computer will relearn pattern. It's not like it's storing there year worth of data.
It's couple trips only.

 

Lots of thinking, 'steps' and risk if it flubs.

For no value.

Just swap the battery, truck off.

Ground off first, Pos off second. Pos on first, ground on last.

Prevents any arcing, which is much more risk to the systems than loss of voltage.

Even if our ECUs are 'learners' (are they?), it will relearn very quickly.

 

Because the battery is an integral part of the electrical system, and ECUs don't like it when it's gone. You risk taking it out.

The old 'pull the cable to check the alternator output' (at no risk) ended when ECUs started appearing, even on the early ones.

So that's been what? Almost 30 years?

 

I've never had any issues.

 

I think he's worried about losing all his presets on apps and radio and such. That would be my concern as well. All the destinations already saved in the Nav system... not to mention having to relearn the garage door opener (if so equipped).

Having all that info disappear would be a pain in the ass. I could give two shits about the ECU learning how I drive.

 

Understood. Didn't say it would blow up every time. Just that there is a high risk. One slip and draw a high amp arc and...........

Kinda like 5 empty chambers of a 6 shooter with one round pose a low risk.

 

I disconnected the battery cables on my 2014 Tacoma to put those fuzzy red and green things on the terminals. The radio remembered its presets without any kind of help.

 

Good to know...

 

I do have more electronics in the truck that I would prefer to keep powered up while changing the battery. I focused on the ECU but as pointed out it will readjust in a few drives. Though it does seem like computers in general are more likely to die or get messed up when they lose power suddenly. May not be a concern with automotive applications but avoiding it would avoid the chance of a problem. At least that was my thinking. So has anyone plugged the truck into another vehicle through the power outlet and can confirm it's safe to do so?

 

Thanks for the link DoorDing. The last bullet point sounds very promising. "If either or both of the vehicles do not have "hot at all times" cigarette receptacles, plug the Y-cables into the jumper harness, then attach the positive battery clip to the alternator positive terminal and the negative clip to an engine ground on either or both vehicles. So my plan is to put together a cable with alligator clips on both ends and a fuse on the positive side. Keeping the connections away from the battery sounds like a much safer approach. I'll report back after the success/failure.

 

Depends on how long the battery is disconnected.

 

Then your damn lucky.

 

20% is a lot more than I like!