[kevintomb]

Have a 2015 Sonata SE, base engine. Old battery about 7-8 years old. Was having issues, with it going low on cold mornings. Jump start would always make it start though.

Wife went to walmart got new exact same battery, had them install it. Wife drove it home, and next morning, dead. The dash lights up, and interior lights work, but when put to start no starter cranking at all, and dash lights go out totally.

Jump starting does nothing either now.

Battery was brand new and reads 12.8 volts. I checked the terminals, cleaned them to make sure and retightened and still same result??

 

[Big Buford!]

Sounds like you have done everything necessary to exonerate the battery....must be another cause....
Check starter and associated relay(s)....

 

[CumminsFan]

WALMART is your problem. How do you know that the WALMART Employee reattached everything correctly? What is the battery voltage when you are trying to start the car and when the engine is running?

 

[kevintomb]

WALMART is your problem. How do you know that the WALMART Employee reattached everything correctly? What is the battery voltage when you are trying to start the car and when the engine is running?

I rechecked connections, they seemed okay.
Engine will not start, but did once right after my wife started it at walmart and came home.

I will check when trying TO start here soon.
In fact even trying to jump start it with my known good other car did nothing.

 

[oragex]

Your battery appears really discharged so it won't start unless it charges a little bit. keep the other car running and with cables connected for at least 15 minutes, to recharge your battery to a minimum level. And I guess you want to measure for parasitic current drain

 

[kevintomb]

Your battery appears really discharged so it won't start unless it charges a little bit. keep the other car running and with cables connected for at least 15 minutes, to recharge your battery to a minimum level. And I guess you want to measure for parasitic current drain

Sadly my other car is at work with wife...so no way to do that right now

 

[peachferrari]

Your battery appears really discharged so it won't start unless it charges a little bit. keep the other car running and with cables connected for at least 15 minutes, to recharge your battery to a minimum level. And I guess you want to measure for parasitic current drain

Not if it's measuring 12.8 volts, that would be fully charged.

Sounds more like a bad connection between the battery and starter or battery and ground--which would explain why jump-starting doesn't help.

 

[oragex]

Battery 'was' 12.8v the day of the purchase, after sitting overnight. Worth checking the voltage. Starter cable may be the other thing indeed

 

[kevintomb]

Battery 'was' 12.8v the day of the purchase, after sitting overnight. Worth checking the voltage. Starter cable may be the other thing indeed

Day of purchase was last nite. and Today it measures same voltage, Actually it was 12.7 typo!
It started and ran last nite rite after they installed it.

Tried a few more things, now reads 12.45 about and when trying to start it reads about 12.18, but all lights and heater fan stop and shut off.

 

[cj133]

Are the connections to the battery clean and tight?
After you try starting do they feel warm? Can you wiggle or move them by hand?


Dirty or loose connections cause resistance and resistance causes voltage drop from current. The more current you pull the more drop, and heat you'll get.
That's the very first thing I'd be looking at. Making sure the connections are good and tight, can't be moved by hand, and that the wires are secure to the connectors and not all nasty, corroded and hanging on by 1 strand.

 

[oragex]

Look at the Positive connector, there is a 180amp fuse in a plastic piece. see if it's blown. Push harder on the brakes pedal when turning the key. If you have Start button, push with the fob against the button. Wiggle the starter cables too

 

[kevintomb]

Are the connections to the battery clean and tight?
After you try starting do they feel warm? Can you wiggle or move them by hand?


Dirty or loose connections cause resistance and resistance causes voltage drop from current. The more current you pull the more drop, and heat you'll get.
That's the very first thing I'd be looking at. Making sure the connections are good and tight, can't be moved by hand, and that the wires are secure to the connectors and not all nasty, corroded and hanging on by 1 strand.

Terminals look near perfect, nothing visually wrong at all. I cleaned terminals and rehooked them back up.
It is really acting odd, lights and dash lights come on, but when locking with fob, tail lights are not flashing now.

Almost now wondering if some type of logic issue, but nothing was wrong literally last nite.....no idea.

Took this new battery back to exchange for another new battery, just in case something is wrong with it to rule it out at least.....not sure what else to check now

 

[kevintomb]

Look at the Positive connector, there is a 180amp fuse in a plastic piece. see if it's blown. Push harder on the brakes pedal when turning the key. If you have Start button, push with the fob against the button. Wiggle the starter cables too

Fuse looks/tests good

 

[cj133]

Terminals look near perfect, nothing visually wrong at all. I cleaned terminals and rehooked them back up.
It is really acting odd, lights and dash lights come on, but when locking with fob, tail lights are not flashing now.

Almost now wondering if some type of logic issue, but nothing was wrong literally last nite.....no idea.

Took this new battery back to exchange for another new battery, just in case something is wrong with it to rule it out at least.....not sure what else to check now

Does yours have the little yellow or whatever color it is "travel disconnect" located in the interior fuse block? It's really a plastic thing that holds two fuses that they pull to transport the car etc. Mine was loose and causing issues. I highly doubt it's your issue but it's easy to check.

 

[kevintomb]

Wife tried to return battery but they tested the new one and said it was perfect.

Put back in car, and tried, and of course nothing. I did notice headlights seem fine, until you try to start engine then they go totally dark.

 

[cj133]

Wife tried to return battery but they tested the new one and said it was perfect.

Put back in car, and tried, and of course nothing. I did notice headlights seem fine, until you try to start engine then they go totally dark.

That sure sounds like a bad battery.

I wouldn't trust anyone... At this point I'd go buy another new battery from a parts store and put it in. Then after it works go fight with the other place

 

[peachferrari]

What exactly does it do when you try to start it? I'm wondering if you blew some other fuse like for the ignition or something.

 

[tacthecat]

Does yours have the little yellow or whatever color it is "travel disconnect" located in the interior fuse block? It's really a plastic thing that holds two fuses that they pull to transport the car etc. Mine was loose and causing issues. I highly doubt it's your issue but it's easy to check.

Taillights not flashing is likely the brakelights - that circuit must be working to start most cars having an automatic transmission. Could be fuse, brake pedal switch,... (btw most newer vehicles turn off dash and lights when starting.)

 

[ts27330]

Have a 2015 Sonata SE, base engine. Old battery about 7-8 years old. Was having issues, with it going low on cold mornings. Jump start would always make it start though.

Wife went to walmart got new exact same battery, had them install it. Wife drove it home, and next morning, dead. The dash lights up, and interior lights work, but when put to start no starter cranking at all, and dash lights go out totally.

Jump starting does nothing either now.

Battery was brand new and reads 12.8 volts. I checked the terminals, cleaned them to make sure and retightened and still same result??

Does anything work (lights, etc), if no could be a fuse.
Also, new battery could be bad. Take it back and replace.

 

[flemmons]

Turn on headlights, blow the horn and see if headlights dim or go out. If they do, battery is bad or one of the connections is bad. Measure on the cable clamp while attempting to start. Voltage should be exactly the same as that measured on the battery terminal itself. Also, check the other end of the ground cable where it bolts to the body. It is a short cable and may have been dislodged when the battery was changed.