Battery Dead - Want am I in for?

[chriskav]

I have a 2003 Gen 3 Viper. Roughly, 2 months without starting and battery is dead. I read through some threads, and seeing a mix of things that might go wrong now. Guidance or how to handle, appreciated:

- Assuming I should buy a battery charger, not jump it?
- If I charge it, keep the hood down?
- Seeing that I might need to reset it?
- Also saw it might not stay on?

 

[MoparMap]

I don't think these cars are quite as picky about batteries as some European cars or other more high tech stuff. Probably the easiest thing would just be to pop the truck and charge the battery directly if you can. That would take most of the variables out with the alarm system. Even if it was armed, I have a feeling as soon as you start charging it you would likely be able to disarm it with your keyfob or the key itself if it started going off. That being said, if you charge it from the trunk you wouldn't even have to worry about that I don't think.

And that's not to say that a dead battery can't or won't cause strange issues that can be hard to track down, more just that I don't think the Viper is as sensitive in the sense that I don't think things need a lot of resetting or calibrating or anything like that. You could probably jump it and the alternator should keep it going, but if the battery is way dead that's generally just not very good on the system as the alternator might be trying to push max charge through things. If it's that far gone it might be easier to just buy a new battery for it and start fresh, but I'd think if it was regularly driven before being parked for 2 months that it wouldn't be too bad and you could probably even jump it fine. I know I've done that on mine when it had enough juice to turn the engine over some, but not enough to start it.

 

[chriskav]

I don't think these cars are quite as picky about batteries as some European cars or other more high tech stuff. Probably the easiest thing would just be to pop the truck and charge the battery directly if you can. That would take most of the variables out with the alarm system. Even if it was armed, I have a feeling as soon as you start charging it you would likely be able to disarm it with your keyfob or the key itself if it started going off. That being said, if you charge it from the trunk you wouldn't even have to worry about that I don't think.

And that's not to say that a dead battery can't or won't cause strange issues that can be hard to track down, more just that I don't think the Viper is as sensitive in the sense that I don't think things need a lot of resetting or calibrating or anything like that. You could probably jump it and the alternator should keep it going, but if the battery is way dead that's generally just not very good on the system as the alternator might be trying to push max charge through things. If it's that far gone it might be easier to just buy a new battery for it and start fresh, but I'd think if it was regularly driven before being parked for 2 months that it wouldn't be too bad and you could probably even jump it fine. I know I've done that on mine when it had enough juice to turn the engine over some, but not enough to start it.

Thank you for your help and advice. I followed your advice and hooked up the battery to charger for roughly 8 hours and checked on it every hour. No luck, assuming the battery is dead. What would your be recommendation and if its to get a new battery, what do you recommend. thank you again

 

[Steve-Indy]

Save yourself some grief and get an AGM battery in Group 34 size (top terminal) with a good warranty...such as Interstate MTZ or an Odyssey. Keep car on a battery tender and consider using "hibernation mode" when not on a tender.

 

[chriskav]

Save yourself some grief and get an AGM battery in Group 34 size (top terminal) with a good warranty...such as Interstate MTZ or an Odyssey. Keep car on a battery tender and consider using "hibernation mode" when not on a tender.

Thank you

 

[chriskav]

Thank you

Is 800 cold cranking Amps to much or should I do 700?

 

[MoparMap]

More is generally better, especially since you've got a lot of displacement to turn over. That being said, I've managed to jump my car with one of those portable Li-Ion packs that's only "designed" to jump a large V6 or small V8 okay. Mopar tends to use gear reduction starters for some extra oomph. I can't find the factory battery rating in my service manual to compare though. Long story short, I don't think you can ever really have too much. The starter is only going to pull what it's able to pull, and the cables and everything else should be designed with that in mind.

 

[chriskav]

Thank you, I went to get the interstate MTZ group 34 800, however they did not not have one. Went with next best MTX 740 and was able to get it started. Thank you

Next project is the evap lines, Ive been told by two different places that they will need to cut a hole in the trunk to replace. Any thoughts are appreciated.

 

[MoparMap]

Oof, yeah, the service manual instructions on that one look fun. I would first try to confirm exactly where the problem is though before doing that kind of surgery. I don't think it's actually that hard to do if you had to make the cutout, it's just kind of daunting to cut a big hole in the truck like that.

I know on my car I have pulled the front strut tower bracket in the engine bay several times and there are some evap lines that run on the back/bottom of it. I have forgotten to unclip them several times and they are molded plastic and have broken on me due to all the heat cycling and the stress I put on them when pulling the brace out. If you are getting a fault that would be the first place I'd look just because it's so easy to get to. The evap solenoid is mounted on the front side near the PCM on the inner fender. I'd check the lines there to the intake manifold and confirm they are okay before even thinking about cutting the trunk open.