Battery not charging

[wrcsixeight]

How are you taking voltage readings? What you have described make no sense if you are using a Digital Multi Meter and measuring at the battery terminals.

If you are relying on a dash gauge panel voltmeter then okay. I Am not familiar with your vehicle but I could see how a missing ground strap might give the readings you've indicated here.

Have you ever put that battery on a regular charger?

Harbor freight sells a DMM, sometimes on special for $2.99. It is surprisingly accurate and a great help when dealing with electrical issues

 

[tinmanSC]

Originally Posted By: wrcsixeight
How are you taking voltage readings? What you have described make no sense if you are using a Digital Multi Meter and measuring at the battery terminals.

I am measuring with a digital multi meter. I have tested this multi meter this week before I started this work (i had one go bad some years ago that drove me crazy! it took me down the wrong diagnostic path for several days).

Quote:

If you are relying on a dash gauge panel voltmeter then okay. I Am not familiar with your vehicle but I could see how a missing ground strap might give the readings you've indicated here.

The 2000 Lexus GS300 model does not have a voltage indicator on the dash. It just has a battery light that comes on if there is a problem. When I first put in the key and turn it to "on" the car the battery light does come on, but as soon as the car is started it turns off. Pretty standard.
Quote:

Have you ever put that battery on a regular charger?

No, I don't have one.

It has been in the car the entire time I have owned the battery. It has never been out of the car and never been disconnected except for this week when I cleaned the terminals as stated before.


Yeah, it's totally freaky. I don't get it either. I just got back from driving to the store and back. All is well. No problems to report. If I had done this yesterday, i'm sure it would have had a problem. The issue was pretty consistent and now it seems to be gone.

 

[tinmanSC]

Ok, so I have a theory. But i'm not nearly as good as wrcsixeight is with electrical issues, so it may be horse feathers, i donno.

I'm wondering if there isn't enough grounding on the engine for the starter to work correctly. Without this strap (which is, by the way, attached to the bellhousing on the transmission about 2 inches from the starter. It may even share a common bolt) it turns over so slowly, but it's using all the ground it can. When the engine is running it's grounding to the alternator and doesn't have to jump off the engine to get a ground. Does it work this way?

 

[wrcsixeight]

Bizarre readings. You tested the actual battery posts/studs or on the battery clamps? That's the only thing, besides a failed DMM which makes sense. There was a poor connection between battery post and battery cable clamp.

If the actual battery was at 10.5 volts there is no way your short drives brought it up to it's current voltage.

Automotive Alternators are just not that good at fully recharging a fully discharged battery. It takes many hours. there is no way around that fact. Either it was nearly fully charged and your readings were taken on the clamp that had a poor connection, or it is far from fully charged now, and your 12.7 is surface voltage.

The only other possibility I can think of is that the debris that naturally sheds off the batteries plates and collects in the bottom of the cell had built up and temporarily shorted out the cell. Further driving flattened out the debris and eliminated the short within the cell. If this is the case, you will have the same original issue an a couple days or weeks.


The Ground wire you replaced does not explain the numbers you posted.

You should really acquire a 120 volt grid powered battery charger, even if it is a just 5 dollar maintenance charger similar to a battery tender.

 

[wrcsixeight]

I am a believer you cannot have too many grounds. Some might argue that can lead to ground loops and electrical interference. That is a little beyond my knowledge.

I do know that 85% of all automotive issues are caused by bad grounds, and that chasing down other possible culprits is foolhardy until you can eliminate the grounds as an issue

I have added extra grounds between my alternator and engine, alternator and frame, battery(s) and engine.

Before I upgraded the size and amount of grounds I added a bigger (+) wire from alternator to batteries hoping for more charging current, and saw some improvement, but it was not until I put an additional 4 awg cable from alternator (-) stud to the battery that I was able to see over 110 amps out of my 130 amp alternator when my batteries were low and the engine was cool and the alternator still cold.

 

[tinmanSC]

Originally Posted By: wrcsixeight
Bizarre readings. You tested the actual battery posts/studs or on the battery clamps?

I tested both and saw no difference. I mostly tested on the posts, but a few times I did test on the nut that holds the battery clamp tight. There was no different in any of my readings from these two points at any time.

I tend to discount the theory that my DMM is faulty. It has worked flawlessly (to my knowledge) since i purchased it. Before I started this, I tested the voltage on several batteries (AA, AAA, 9v) and on another car battery. All were ok and measured as expected. I also tested the ohms resistance on some rather expensive speaker wire from a manufacturer that posts details specs about it, the DMM reported as expected with increased ohms by distance according to the speaker wire manufacturer's spec. All clear.

Honestly, I don't know what to make of this issue. It seems so strange. I have to admit, i want something else to go wrong to give further diagnostic data... I guess I could disconnect the grounding strap for a few days and see what happens.

 

[brianl703]

Originally Posted By: wrcsixeight


You should really acquire a 120 volt grid powered battery charger, even if it is a just 5 dollar maintenance charger similar to a battery tender.


I use this one:

http://www.allelectronics.com/make-a-store/item/BC-100/12V-1A-CHARGER-FOR-LEAD-ACID-BATTERIES/1.html

I cut off the plug and replaced it with a cigarette lighter plug.

It has a red light that changes to green when the battery is fully charged. If it never changes to green, either the battery's float current is too high (and it's going to fail more sooner than later) or there is excessive parasitic draw.

 

[tinmanSC]

I just went out in the garage and tested the battery and clamps. The battery with the car off and no load shows ~12.9v on the battery AND the clamp AND the wire leading off the clamp. Under load and the engine off it drops to ~12.5-12.7v. With the car on, they all read ~14.1v.

 

[wrcsixeight]

Originally Posted By: brianl703

I cut off the plug and replaced it with a cigarette lighter plug.


There are a few issues with doing it like this, but nothing really major. It is only a 1 amp charger afterall.

The cigarette socket has to be live with the keys out of the ignition for this to work. Obviously you knows yours is live otherwise the lights would not illimunate. I say this for others wanting to do the same thing.

Most vehicles have a very long length of 18 awg wiring leading to the Ciggy socket, through multiple connectors. Simply put, each connector drops the voltage, the longer the wire drops the Voltage and it is too much resistance for a 1 amp charger to really return much into the battery. It could take a week to fully charge a battery which began at 80% when It was plugged in.

It will still work, it would work better if the ciggy plug socket were wired directly to the battery, over some 12 or 14 awg wire.

 

[wrcsixeight]

Well let's rule out your tester and your method, and your current battery voltage readings indicate a healthy, fully charged(or very nearly so) battery, and your charging system is working properly.


If your battery were actually 100%, the regulator would probably limit the voltage to 13.6 or so. That voltage is considered a float voltage and keeps the battery from using water.

Perhaps the missing ground cable did keep the alternator from charging the battery. But your voltage readings IIRC returned to the 12's and 14's before you replaced it, and only cleaned the other grounds and battery cables.

What surprises me the most is your current voltage readings. How far have you driven it since you read 10.5 volts?

What size and brand/ age of battery is it? If It is just a short driving distance, and a big battery, I'm getting a Lexus alternator, cause that is impressive recharging ability.

 

[tinmanSC]

I have driven perhaps 15 miles since replacing the grounding strap. The battery is a NAPA Select, I think that's what it's called. It's their most expensive. Frankly, this battery is amazing. I've had this thing for 2 years it's been through Minnesota winters at -20F (this is why i purchased it), starts like a dream, SOMEONE *cough* not me *cough* has run it dead a few times. Always recharges with no trouble.

 

[wrcsixeight]

It is the orbital select? Look kind of like an Optima six pac style but black? AGM

Or is it rectangular in 2 dimensions and does it have Caps to check and refill the electrolyte? Flooded.

Before you replaced the Ground strap, you said you cleaned the grounds and battery terminals and it was running better after that. Approximately home many miles since that cornerstone?

Also Check the battery Voltage in the morning. Any surface charge should have dissipated by then. Some batteries really hold on to a surface charge, especially if it is cool/ cold out. But it is also a sign that they are still healthy.

It looks like you are in the clear though, Congrats!

 

[tinmanSC]

Originally Posted By: wrcsixeight
It is the orbital select? Look kind of like an Optima six pac style but black? AGM

Or is it rectangular in 2 dimensions and does it have Caps to check and refill the electrolyte? Flooded.

It is perhaps the worlds most unassuming-looking battery. All black rectangle with 2 posts on the top marked + and -. Nothing remarkable. It says NAPA on it and has a small NASCAR logo next to the punch outs for the month/year of purchase. It does not open and is a maintenance free battery.
Quote:

Before you replaced the Ground strap, you said you cleaned the grounds and battery terminals and it was running better after that. Approximately home many miles since that cornerstone?

After I cleaned the battery posts and grounds I did drive it around for perhaps 10 minutes. I then rechecked the voltage while off, under load and engine running. I don't recall the exact number, but the difference was small enough as to be forgettable, perhaps 0.05v. Essentially no change. It did start a little easier, not sure why that is. Perhaps it was just warm.
Quote:

Also Check the battery Voltage in the morning. Any surface charge should have dissipated by then. Some batteries really hold on to a surface charge, especially if it is cool/ cold out. But it is also a sign that they are still healthy.

It looks like you are in the clear though, Congrats!

I will check it in the AM. Thanks.

 

[tinmanSC]

Oops, I lied. It does have 2 caps.

 

[wrcsixeight]

Yeah, that is a regular flooded battery. Napa usually has good parts with their label pasted on. Whoever made that battery for them (Most likely Exide ,Johnson controls, or US battery) built it to a much better standard than they would have for Walmart.

I still have a hard time believing that it is fully charged with your 10.5 volt readings in the early posts. A flooded battery just cannot accept enough amps to charge as quickly as your driving would provide.

You really need a Hydrometer and test the specific gravity, but the cheap ones are generally highly inaccurate and only good to compare cell to cell.

Sometimes when batteries are failing, they will still read high voltage. Think of a new battery like a 5 gallon bucket. When the bucket is full, it reads 12.8 volts. As the battery ages, the bucket gets smaller, but when this bucket is filled, it will still reads 12.8 volts.

Since the bucket is smaller, it also fills quicker. This bucket analogy is not 100 % accurate by any means. Sometimes the bucket has a crack and cannot be filled to the top. 12.4 volts. Sometimes there is a layer of saran wrap over or near the top of the bucket and nothing gets in.

Really, If I lived in Minnesota, with a 2 year old starting battery that has been abused by draining it to 0 several times, with winter coming, I would not leave home without Jumper cables, or a fully charged jumper pack in the trunk. It might last the winter, or it might leave you stranded on the coldest night/ deepest blizzard of the year, when you find yourself underdressed and out of cell phone range.

The best lead acid battery in the world is damaged ( not necessarily destroyed) by draining it to zero. That is fact and not debatable. You have a very well built battery, but it has been abused. You never really own a battery, you rent one.

 

[tinmanSC]

The saga continues. I don't know why this battery exhibits such strange behavior. I went out this morning and started it, and it tuned over very slowly. The voltage read 11.8v at the posts. I guess a new battery is in order after all. wrcsixeight was right all along!

 

[wrcsixeight]

Well you know I had a very hard time believing your battery was fully charged in the time you drove the car, and I've been racking my brain as to how it could have happened, and not really liking any of the possibilities.

Lets say your battery has a very reduced capacity but will still hold 12.7 volts with no load.

It is possible the Lexus has an electrical drain. The stereo memory, computer memory and remote door locks all use some battery power, enough to drain a healthy battery in 5 to 6 weeks. It should not be enough to drain your reduced capacity battery overnight unless there is a more significant electrical drain.

Put your multi meter on DC amps and hook it inline with the battery negative cable to test the parasitic draw. Most DMM's cannot handle more than 10 amps, but that draw would drain a fully charged healthy battery in about 6 hours, and cause a very large spark when removing one of the battery cables.

Sparks and batteries can be dangerous, especially if they are low on water and have been charging recently, so take precautions. Good Ventilation, eye protection, and have a solution of baking soda in water to neutralize acid.

This is why they say when jump starting a car, to hook the last ground wire something grounded other than the battery, so the spark does not occur where there might be hydrogen gas and go BOOM!

You can try just putting your current battery on a charger for a while.(12 hours) It might last you the winter, or just another week.

 

[brianl703]

Originally Posted By: wrcsixeight

Most vehicles have a very long length of 18 awg wiring leading to the Ciggy socket, through multiple connectors. Simply put, each connector drops the voltage, the longer the wire drops the Voltage and it is too much resistance for a 1 amp charger to really return much into the battery.


My Saab 93 uses 2.5mm2 wire to connect to the lighter socket, which is a little larger than 14AWG. This wire is connected directly to the dashboard fuse panel, which in turn is connected to the underhood fuse panel with a 6.0mm2 wire, which is a little larger than 9AWG wire.

I mainly use this charger with my Saab 93.

 

[wrcsixeight]

That was nice of Saab to not cheap out on the Ciggy plug wiring.

I have re wired my 5 Ciggy plugs with 10 awg, directly to the Auxiliary batteries. I now use a different type connectors for most devices, as the spring loaded ciggy plug might be convenient, but a spring leaded contact doesn't really cut it for more than a few amps.

I have a 14.5 volt wall wart that uses the other type of connector and does the same thing as your system. It is only 0.5 amps, and really cannot do much charging, but that's why I have Solar, a 25 amp charger, and an upgraded alternator charging circuit

 

[tinmanSC]

Well ok fine. The saga is over. The battery was the problem. I took it to Advance Auto Parts and they tested the battery. The test result was "Battery Fault." They put it on their charger for a few hours and then retested, the result was the same. I took the battery back to NAPA. (you may be wondering why took the battery to AAP and not NAPA. I did take it to NAPA and they didn't have any testing equipment and no free charging of batteries. They told me to go to AAP. Sigh. Anyway...) They accepted AAP's fault diagnosis and gave me a pro-rated replacement.