2010 Hyundai accent battery not charging fully?

[Vikas]

A typical vehicle electrical system can be approximated as constant supply voltage. The current decreases as you increase the resistance. For cranking the starter, huge current is needed. That circuit has to have very low resistance like in mill ohms range. So if you have corrosion or bad cable, you have got big problems.

The current needed to keep computer memory and radio etc alive is very small, in mill amp range. So the effective resistance of that circuit is huge. The resistance added by corrosion is insignificant here.

I am not a good teacher either and I am sure somebody else would explain it better.

 

[Vikas]

Originally Posted By: Michael_P
Then based off of this, we can rule out the battery cable. If I were Rand, I would not even test it.
You had a valid point in your original reply. He should indeed check the battery cable and if it is bad, it could hamper charging.

 

[circuitsmith]

Make sure all systems are "asleep" and parasitic drain has fallen to its minimum before measuring battery rest voltage.
Battery voltage sag with load is not linear; and a small drain can drop the bat voltage more than you'd expect.

 

[wrcsixeight]

It takes time to fully charge a battery, no matter how powerful the charging source might be.

Getting a healthy battery from 80% charged to 100% charged takes about 4 hours, when the charging source holds voltages in the mid 14's at 77F. Lesser voltages greatly increase the amount of time required to reach 100%.

When a battery is not regularly returned to 100% charged, it will then require much much longer to reach this true 100%, and no Automatic charging source is going to hold absorption voltages in the mid 14's for long enough to actually achieve a true 100% state of charge, no matter how flowery and persuasive their documentation/ marketing is.

Auto makers really do not care about battery longevity, and battery longevity is determined by how close to 100% charged the battery gets to live.

The anal retentive Bitoger seeking maximum battery life should use external charging sources to get the battery to 100% charged, instead of expecting the alternator and vehicle's voltage regulator to do the job.

As no matter how much the general public loves to think the alternator is some magical instant battery recharger that makes free power, the fact it is does a poor job at returning a depleted battery to a true 100% full, and the battery is not happy other than when it is indeed fully charged.

You can try and charge your current battery to full via a plug in charging source, but the battery's capacity is compromised, it can only hold some fraction of what it could when new.

This cannot be restored. Once heavily sulfated it either stays sulfated, or the sulfates get knocked from the plates collecting on the bottom of the battery opening up surface area for the chemical reaction to tke place, but the with capacity loss with plate material shedded.

In my opinion, Pulse desulfation chargers are ineffective on a sulfated battery. If they worked the guys who deeply cycle batteries on boats would praise them. They do not. Only here on Bitog are they thought to be effective, and only by those that own them, who can't actually test remaining capacity and quantify any improvement there of afterwards.

A forced overcharge at 15.5 to 16 volts( called an equalization charge) is the best way to restore battery capacity back to its maximum remaining potential, but this remaining potential is likely well below the original 'when new' capacity.

And getting the battery to 15.5v+ and holding it there for the required time requires special equipment, and a human to monitor the process to stop the charging if the battery gets too hot. 120F is the maximum, and once battery temp starts rising at these high voltages, it can rise exponentially quickly and things can get ugly.

And there is no guarantee an EQ charge is going to be effective. Most often it is too little, way too late, but the person doing the EQ then has a better idea of how to keep their next battery happier for longer life.

But perhaps not. It is easier to point fingers.

 

[Quattro Pete]

Originally Posted By: wrcsixeight
The anal retentive Bitoger seeking maximum battery life should use external charging sources to get the battery to 100% charged, instead of expecting the alternator and vehicle's voltage regulator to do the job.

Having to do that after every drive, every day, is going to get old pretty quick, even for an anal retentive BITOGer. How much more life (on top of the normal 6 years) is it going to add to my battery, maybe 2 extra years? I think I'll pass.

 

[901Memphis]

Originally Posted By: Quattro Pete
Originally Posted By: wrcsixeight
The anal retentive Bitoger seeking maximum battery life should use external charging sources to get the battery to 100% charged, instead of expecting the alternator and vehicle's voltage regulator to do the job.

Having to do that after every drive, every day, is going to get old pretty quick, even for an anal retentive BITOGer. How much more life (on top of the normal 6 years) is it going to add to my battery, maybe 2 extra years? I think I'll pass.



If you have a garage it doesn't have to be every day, even once a week or month wouldn't be bad if I had an outlet close to where I Park.

 

[Quattro Pete]

Originally Posted By: 901Memphis
Originally Posted By: Quattro Pete
Originally Posted By: wrcsixeight
The anal retentive Bitoger seeking maximum battery life should use external charging sources to get the battery to 100% charged, instead of expecting the alternator and vehicle's voltage regulator to do the job.

Having to do that after every drive, every day, is going to get old pretty quick, even for an anal retentive BITOGer. How much more life (on top of the normal 6 years) is it going to add to my battery, maybe 2 extra years? I think I'll pass.



If you have a garage it doesn't have to be every day, even once a week or month wouldn't be bad if I had an outlet close to where I Park.

If you only do it once a month, then your battery will be undercharged majority of the month anyway.

 

[barryh]

As I said in my earlier post it's impossible that a modern car will leave you with a 100% charged battery so I do a charge once per week to 14.6 volts. The car is generally only used for 2 days and then sits for 5 days so a full charge at the beginning of it's rest period does the job. Yes it's a PITA that it needs to be done but if you get organized with a shelf mounted charger and long leads it only takes seconds to hook up the charger.

The other 5 days I use my 1979 simple motorcycle with zero current draw when resting. The bike does fully charge the battery which holds it's 13.05 rested voltage until it's next use and never needs a top up charge. Modern cars are hardly progress.

 

[gizzsdad]

Originally Posted By: Quattro Pete
Originally Posted By: wrcsixeight
The anal retentive Bitoger seeking maximum battery life should use external charging sources to get the battery to 100% charged, instead of expecting the alternator and vehicle's voltage regulator to do the job.

Having to do that after every drive, every day, is going to get old pretty quick, even for an anal retentive BITOGer. How much more life (on top of the normal 6 years) is it going to add to my battery, maybe 2 extra years? I think I'll pass.


Normal has been four years for us for as long as I can remember. I try to top off mine overnight every two or three weeks in winter, and after every car wash during which I have the doors open (lighting all the dome lights and ground effects lights) for long periods of time while drying out around/under the doors, whisk brooming the bad spots and cleaning dash, windows, etc.

This got me to 5 1/2 years+ on my last car with no worries, especially knowing that the charger is checking the condition of the battery before charging. Wife's truck is coming up on 6 years, and with her short tripping, she had never been past 4 years - ever.

I also add a dribble of distilled water to keep cells topped off about once a year.

 

[Rand]

I am not plugging the car in every day. its not practical. Car is outside with hood towards road.

I have charged it overnight a few times. Its always back down to
Seems like half the people replying in this thread are giving generic answers and not even reading what I have previously done.

 

[Vikas]

deleted

 

[circuitsmith]

I drive 2-3 times per week, 30-60 minutes per trip.
Every 3 months I charge the battery on a variable DC supply set to 14.5V for ~12 hours, then equalize for an hour at 15.5V.
My OEM battery was going strong when I replaced it at 9 years old.
Just didn't feel comfortable going through a 10th winter.

 

[Quattro Pete]

Originally Posted By: Quattro Pete
Originally Posted By: Rand
I am having an odd sort of issue with this 2010 Accent.

After it sits overnight the battery shows about 12.35v.

I have charged it a few times and it seems like within a day its back down again.

My 530i is just like that. If I let the car's alternator charge the battery, after I shut down, battery voltage shows about 12.4V.

I just noticed wife's Q5 is the same way. Starting to think that's how it's supposed to be.

 

[Jetronic]

Originally Posted By: Rand
Ok so in 2009(2010 model year) they switched to smart alternator system.



Previous to posting this thread..I googled for about 15min and couldn't find anything about it being a "smart alternator"



look at the a&lternator: there's the fat 12v charge cabel going there. then there's the the field coil agitator which is a small gauge only. you could on old cars get a tach signal from there aswell but anymore wires, esp on a modern car, and you're likely looking at a smart alternator.

Does the ground conection on the battery have a battery condition sensor on it?


Easiest way to check for bad connections is with the engine running.

Put one end of the multimeter on the ground terminal of the battery, and use the other one on the alternator body, the engine block, the gearbox and the body. Any volatge reading higher than 0V* means a poor connection, and by taking all these readings you can find the bad part quickly.

You can do the same with the positive side, but there's fewer measurements: positive terminal on the battery and positive on the alternator.

*The higher the amperage draw, the higher the voltage loss will be. By measuring resistance you will not find the fault as the amperage draw is minuscule.