Battery dead, How to charge the battery?

[digmyGenesis]

CAR: 2015 Genesis Sedan 3.8 Technology AWD Canada

Do I really need to remove the battery before I can charge it? This seems crazy. The manual is not very clear.



I want to charge the battery from the + and - connector under the front hood. But the manual says:

NEVER attempt to recharge
the battery when the vehicle’s
battery cables are connected
to the battery.

What am I missing? I guess I need to disconnect the battery to be able to charge it. ?

 

[kn5owa]

Seems crazy to me too

The alternator charges the battery with the cables connected every time it spins.

I would ignore the manual - the terminals under the hood are there for a reason.

 

[digmyGenesis]

Has anyone successfully charged the batter using the front hood connector? I need to know. I hate to ignore the manual. They are in bold letters

 

[Mark_888]

Has anyone successfully charged the batter using the front hood connector? I need to know. I hate to ignore the manual. They are in bold letters

I charged the battery on a 2009 Genesis using the front hood connectors without any problem. The warning they give is probably required by their lawyers, since a lot of people get injured each year from exploding batteries (the gas emitted from a battery can ignite).

If you are really concerned, as a precaution you can open your trunk lid and lift up the trunk floor cover, so the battery is exposed to fresh air while it is charged, or at the very least when you first attach the charger (even if attached to the front connectors). This will allow any gases to dissipate just in case a spark is caused by connecting the batter charger.

I would make sure to not overcharge the battery, so I personally would not charge it over-night, etc, unless you had a good trickle charger that had sufficient electronics to stop charging when the battery is fully charged. I charged my battery for a couple of hours, and then just drove it from that point on. It may have not been fully charged at that point, but better to undercharge than overcharge.

 

[dougmcp]

For safety you should charge the battery from the jumper posts under the hood they are directly connected to the battery. I use this point to attach my battery maintainer when I leave the car sit for more than a few weeks. Depending on what kind of charger settings you have they may be something like a 15 amp fast charge and a 2 amp trickle charge. You could charge for a couple of hours on fast charge or overnight on trickle and either way you will be ready to go when you need it. You do not need to open the trunk or let anything breathe that's overkill. The battery is likely an AGM battery that is semi sealed and also vented to the outside through the trunk floor.

 

[pmckechnie]

You probably can get away with charging the battery from the front.
I would want to know a few things before I would recommend it.
For instance, why is the battery dead? Is the battery really dead or is there a problem elsewhere in the car?
Is the charger being used accurate? Will it always maintain the charging voltage at 15V or lower? If it goes to high
it can damage some or all the computers in the car.
Are all the vent hoses connected correctly at the battery? Hydrogen gas is generated when the battery is being charged. Hydrogen gas is explosive.
while driving the flow thru ventilation air keeps the trunk ventilated.

If it were my car, I would unhook the neg cable and then the pos cable (in that order). Connect the charger to the battery and charge the battery. Make sure you turn the charger off before you disconnect it. Remember the hydrogen gas?Let the battery cool for a few minuets and check the voltage. It should be at least 12.5V or more.

Reconnect the battery cables, pos first and then the neg. Start the car and check the battery voltage at the battery with the engine running and make sure the voltage is 13.8 to 14.5 volts. If the voltage is close to that then you know your alternator is working.

If the battery goes dead again let me know and I will see if I can help.

 

[kn5owa]

You probably can get away with charging the battery from the front.
I would want to know a few things before I would recommend it.
For instance, why is the battery dead? Is the battery really dead or is there a problem elsewhere in the car?
Is the charger being used accurate? Will it always maintain the charging voltage at 15V or lower? If it goes to high
it can damage some or all the computers in the car.
Are all the vent hoses connected correctly at the battery? Hydrogen gas is generated when the battery is being charged. Hydrogen gas is explosive.
while driving the flow thru ventilation air keeps the trunk ventilated.

If it were my car, I would unhook the neg cable and then the pos cable (in that order). Connect the charger to the battery and charge the battery. Make sure you turn the charger off before you disconnect it. Remember the hydrogen gas?Let the battery cool for a few minuets and check the voltage. It should be at least 12.5V or more.

Reconnect the battery cables, pos first and then the neg. Start the car and check the battery voltage at the battery with the engine running and make sure the voltage is 13.8 to 14.5 volts. If the voltage is close to that then you know your alternator is working.

If the battery goes dead again let me know and I will see if I can help.

your post is well meaning - but so full of misinformation and worthless safety advice, it is laughable.

"See if I can help?" Ok.

So, for example, hydrogen gas is "explosive". Forget it - no problem. That advice goes back to the fifties when batteries were vented and very gassy.

Fooling around with the cables ?? A bit silly.

Just charge the dam thing with a smart charger and be happy.

And use the front connectors (under the hood).

And the manual? Written by lawyers.

Forget that too.

 

[digmyGenesis]

I checked with a meter. The battery is at 3 V. Not sure what happened. I parked the car as usual in the garage. Only thing I can think of is that I bought a new Anker USB charger for my phone and it was connected. I drove the car yesterday and it was fine.

I am using a NOCO 3500 smart charger. It has been 1.5 hour I have been charging. It is still st 25%. I do have the platinum plus warranty and I can toe the car for free to dealer. I am hoping to drive it there. Moving it will be little hard from the garage.

Hopefully it will charge. Still not sure what caused it. May be the trunk wasn't closed properly and some people on this forum said that could be an issue. The trunk light was on. But I doubt that.

 

[Mark_888]

I checked with a meter. The battery is at 3 V. Not sure what happened. I parked the car as usual in the garage. Only thing I can think of is that I bought a new Anker USB charger for my phone and it was connected. I drove the car yesterday and it was fine.

I am using a NOCO 3500 smart charger. It has been 1.5 hour I have been charging. It is still st 25%. I do have the platinum plus warranty and I can toe the car for free to dealer. I am hoping to drive it there. Moving it will be little hard from the garage.

Hopefully it will charge. Still not sure what caused it. May be the trunk wasn't closed properly and some people on this forum said that could be an issue. The trunk light was on. But I doubt that.

Generally batteries are not included in a car manufacturer or extended warranty. My battery drained when I left my rear trunk slightly open for 2 days.

 

[dougmcp]

The NOCO 3500 is only a 3.5 amp charger so it will likely take all night to get the battery to the point where it will start the car.
It is really a trickle charger that can be used as a maintainer but not really designed to quickly charge any battery.
Your battery is about 750 amp/hr and at 3.5 amps per hour it will take considerable time to bring it up to full charge.
Also any battery that has sagged to 3 volts has been severely compromised and even if you get it charged it's life expectancy will be drastically reduced.

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[Midnightsun]

In such a sophisticated car, I cannot believe the entire system does not shut down after X time to avoid draining the battery. If the battery is down to 3v it is most likely toast. Call roadside assistance, they will get her boosted and going or in the worst case towed so it can be delivered to your dealer where I am sure they will set you up with a new battery.

 

[MikeyTG]

Hyundai roadside assistance will come and get your car started. Mine took two jumper packs to get it going - one hooked to the front posts and one hooked to the battery. Make sure they are prepared for that, they might not be familiar with Genesis. Once it is started let it run or take it for a long drive and let the car charge itself.

 

[pmckechnie]

I guess some don't agree with what I say. That is the way the world works. So I will say this once. Then you can choose who to believe.

My last 28 years of work was the owner of a small family auto electric auto shop. We specialized in automobile electrical systems. Every thing
from the battery to the computer systems. I had the opportunity to see what can happen if safety measures were not followed. I have seen the
results of batterys exploding (not pretty). I have seen what can happens if the voltage goes too high for some reason. One because of a bad charger.
The car was 2 years old and was totaled. And so many other things that could be dangerous that I couldn't list them all.
Yes, many things in the manual are put in by the lawyers. If they weren't dangerous the wouldn't bother.
I didn't get my statements from the manual, I got them from experience.
You be the judge.

Just please be careful.

- - - Updated - - -

The NOCO 3500 should be a good charger to use, but as dougmcp said, it will take a long time to charge a dead battery (3 volts is considered dead.)
If whatever caused the battery to discharge is still present (some light on somewhere maybe), the NOCO 3500 may not be able to get the battery charged.
I can't comment on the usb charger, but I can mention that the usb ports stay live when the car is off. Anything plugged into them will stay on.
You can try an overnight or all day charge and see what happens. If the car still will not start you could try a jump connected to the front of the car.

 

[RyanB]

Cant answer your question on charging a battery from the front post but I can say that I tried to jump a friends car with mine using the front post and it wouldn't work. We tried for a good 20 minutes and his car would crank once if at all every try. Then I moved the cables to the rear battery and his car started on the first try. So it seemed to me that some sort of voltage regulation is going on in the front. I myself would disconnect the rear battery cables and hook the charger up to the battery directly with out it connected to the car or remove the battery completely for added peace of mind. Our batteries are AGM style which is made to eliminate Hydrogen gas explosion risk but over charging and overheating is always possible is would assume.

 

[Mark_888]

Cant answer your question on charging a battery from the front post but I can say that I tried to jump a friends car with mine using the front post and it wouldn't work. We tried for a good 20 minutes and his car would crank once if at all every try. Then I moved the cables to the rear battery and his car started on the first try. So it seemed to me that some sort of voltage regulation is going on in the front. I myself would disconnect the rear battery cables and hook the charger up to the battery directly with out it connected to the car or remove the battery completely for added peace of mind. Our batteries are AGM style which is made to eliminate Hydrogen gas explosion risk but over charging and overheating is always possible is would assume.

Although one may not be able to always jump a car using the front connectors, I had no problem charging my battery using the front connectors.

 

[digmyGenesis]

Thanks everyone for all your help. It did work. In the morning after 13 hours the car was back to life. But i didn't want to screw things up. First thing I did put the car on ON position (not start) so I can neautral the car. I was preparing for toeing. I couldn't find a way to disengage or turn off the electronic parking brake. Did I miss something. The car has to be on to turn it off?

They had to drag it. The rear tire was dragging.
It wasn't that bad. They put it on the flat bed truck. Had to drag the length of the car. We sprayed some oil on the floor to make the dragging less. That worked well. I must have missed something. There must be a way to turn off EBS when there is no battery.

In the morning I tried to boost it. It cranked but didn't work. I didn't try many times. Only once. Not sure what is going on. I will post it later.

I used a tiny DC meter. It showed 2.5 volt. Last night. May be I need a proper volt meter for car battery.

 

[Seejay]

The NOCO 3500 is only a 3.5 amp charger so it will likely take all night to get the battery to the point where it will start the car.
It is really a trickle charger that can be used as a maintainer but not really designed to quickly charge any battery.
Your battery is about 750 amp/hr and at 3.5 amps per hour it will take considerable time to bring it up to full charge.
Also any battery that has sagged to 3 volts has been severely compromised and even if you get it charged it's life expectancy will be drastically reduced.

Concur. Interior/trim LED lighting cannot take down a 750 Ah battery to 3V in so short a time. Overnight means something else entirely. It is possible that it is being triggered by open doors or trunk lids.

 

[dougmcp]

Likely a dead cell in the battery and you will end up with a new one while the service department declares all is well.

 

[glennk]

Does anyone know if Costco carries the H8-AGM (V6 Engine) or H9-AGM (V8 Engine) batteries? I know they use Interstate Battery.

 

[circuitest1]

Our 3.8 ultimate is my wife's car. It seems that every time she has an important appointment the car cannot be started due to a dead battery. This has happened six times in less than 1 1/2 years. in the past i usually drove the car to the dealership myself, but the last time i gave up and called Hyundai customer service to have the car towed to the dealership. The car was in our garage and the tow truck operator could not release the electronic parking brake. It seems that the parking brake cannot be released when the battery is dead. Luckily, I had purchased a portable jump starter. The tow truck driver connected it directly to the battery and then seems to have put the car in neutral (not quite sure of what he did), released the parking brake and pushed the car out of the garage. By the way, in the past i have been using the connection points under the engine hood to recharge the AGM battery without disconnecting anything. it takes close to 20 hours for a complete charge. Hopefully all is well that ends well, customer service finally agreed to have the battery changed at no charge. If that does not fix the problem finding a wiring short will be much more difficult.