Replaced my truck's battery a few weeks ago with a Wal Mart Ever Maxx battery (might have been my first mistake!). I don't drive this truck a lot and it sometimes sits for a week at a time. I went to start it last week and it wouldn't start. I checked the voltage and only had 11.4 volts. So I charged the battery overnight at 2 amps and put it back in the truck. Voltage was reading 12.71 volts fully charged. I checked the volts over the next few days and it was gradually dropping. All the way down to 12.06 volts today. When I unhooked the battery cables this morning the voltage jumped to 12.12 and then seemed to have held steady there for a few hours. I have no mods (stereo, fog lights, etc) on the truck so there is nothing "on" that should drain the battery that I know of. The digital clock is always on but I think that has been like that since I owned the truck (7 years). It's a 98 Chevy K1500 x-cab 4X4. I pulled the battery and am charging it again. Guess I should just take it back but wondered if something could be draining it on the truck? I'd be curious to see if the battery loses voltage just sitting on the bench in the garage after I unhook the charger.
Truck Battery Issue
- Thread starter wolfehunter
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Those are usually pretty good batteries. I did have a similar issue with the EverStart battery in my Buick running down when we left it for a week, but that was due to my ScanGaugeII being plugged into the OBDII port the whole time.
I bet there's a parasitic drain somewhere that's causing it to drop off.
I bet there's a parasitic drain somewhere that's causing it to drop off.
JHZR2
Staff member
If you charged it up and then didnt put it back in the truck, rather just let it sit out, how much would it use?
The question is if there is high internal losses/resistance, or if there is a big draw on the truck.
Id put an ammeter inline with the positive cable and see wht the draw is. Report that back.
The question is if there is high internal losses/resistance, or if there is a big draw on the truck.
Id put an ammeter inline with the positive cable and see wht the draw is. Report that back.
Most new vehicles will pull the battery down because of phantom loads such as the ecu. I had one vehicle drive me crazy trying to find what was pulling the battery down. It ended up being the starter.It haad a short in it but still worked.
Wal Mart Eever Max Batteries get high ratings.
Does not sound like any problems with the battery.
Does not sound like any problems with the battery.
Originally Posted By: wolfehunter
Voltage was reading 12.71 volts fully charged. I checked the volts over the next few days and it was gradually dropping. All the way down to 12.06 volts today. When I unhooked the battery cables this morning the voltage jumped to 12.12 and then seemed to have held steady there for a few hours.
It is parasitic drain in the truck, as mentioned above put an ammeter inline with the positive cable and see what the current draw is and report back.
Voltage was reading 12.71 volts fully charged. I checked the volts over the next few days and it was gradually dropping. All the way down to 12.06 volts today. When I unhooked the battery cables this morning the voltage jumped to 12.12 and then seemed to have held steady there for a few hours.
It is parasitic drain in the truck, as mentioned above put an ammeter inline with the positive cable and see what the current draw is and report back.
How many years does a battery typically survive in this truck?
Here's my point. If the battery that you just removed was under the hood for several YEARS, but this new one barely holds a charge for several DAYS... then ask yourself.
1) Did anything change with the truck? Any modifications lately (new alternator), or any new accessories (new trailer brake controller, new stereo?)
2) If nothing changed with the truck other than the battery, and the last battery survived under the hood for several years, then the new battery is suspect.
My Silverado chewed through three Exide batteries in less than two years. One lasted less than 100 days. I tested and checked for draw over and over again. It wasn't the truck, it was the batteries.
Here's my point. If the battery that you just removed was under the hood for several YEARS, but this new one barely holds a charge for several DAYS... then ask yourself.
1) Did anything change with the truck? Any modifications lately (new alternator), or any new accessories (new trailer brake controller, new stereo?)
2) If nothing changed with the truck other than the battery, and the last battery survived under the hood for several years, then the new battery is suspect.
My Silverado chewed through three Exide batteries in less than two years. One lasted less than 100 days. I tested and checked for draw over and over again. It wasn't the truck, it was the batteries.
Keep in mind that if you charge the battery with an AC charger out of the vehicle, you need to wait 24 hours to measure the voltage. There is a "false charge voltage". So charge it, wait 24 hours, check voltage, wait another 24 hours and recheck, should be same voltage, or extremely close.
I had a Walmart MAXX battery and it lasted just under 3 years. I got a new one for free. They were going to test it, but when it needed to be jumped to drive from parking lot to service bay, they realized it was NG.
Now is justification to buy a carbon pile tester from HF. Its really the only way to really load test a battery. Expect the tester to smell hot after the test. Its dealing with a lot of juice.
I had a Walmart MAXX battery and it lasted just under 3 years. I got a new one for free. They were going to test it, but when it needed to be jumped to drive from parking lot to service bay, they realized it was NG.
Now is justification to buy a carbon pile tester from HF. Its really the only way to really load test a battery. Expect the tester to smell hot after the test. Its dealing with a lot of juice.
The previous battery (Action) lasted over 6 years. No modifications at all to the vehicle except I had the original alternator rebuilt. I think that is what contributed to the Action battery losing its life. I can't complain as I got over 6 years out of that battery.
I assume the digital clock that stays on all the time could be a "parasitic draw" couldn't it? I wouldn't think it would be enough to drain the battery down .7 volts over 5 days though would it?
Could someone walk me through putting the ammeter inline with the + cable? I'd like to learn something.
I assume the digital clock that stays on all the time could be a "parasitic draw" couldn't it? I wouldn't think it would be enough to drain the battery down .7 volts over 5 days though would it?
Could someone walk me through putting the ammeter inline with the + cable? I'd like to learn something.
Originally Posted By: wolfehunter
The previous battery (Action) lasted over 6 years. No modifications at all to the vehicle except I had the original alternator rebuilt. I think that is what contributed to the Action battery losing its life. I can't complain as I got over 6 years out of that battery.
I assume the digital clock that stays on all the time could be a "parasitic draw" couldn't it? I wouldn't think it would be enough to drain the battery down .7 volts over 5 days though would it?
Could someone walk me through putting the ammeter inline with the + cable? I'd like to learn something.
If you can get a DC clamp-on ammeter that would be easier, as you just clamp it around the + or - cable. I have an AC one, unsure about the DC ones. If not the ammeter will have 2 connections. Remove the + or - from the battery and clip it to one of the connections and clip the battery to the other. Some DMMs can do this also. Remember this setup is to check very light loads. Even your headlights would be to big a current draw. You can pull fuses to check. If you connect it backwards do not worry it will work either way. If its an analog one, then 0 amps will be center scale.
You mention a rebuilt alternator. Is it possible someone did the alternator wrong, swapped the sense and excite wires? Could be inside the alternator or how its wired outside. If those wires are swapped the alternator will work fine and charge, but will drain the battery when the engine is off.
The previous battery (Action) lasted over 6 years. No modifications at all to the vehicle except I had the original alternator rebuilt. I think that is what contributed to the Action battery losing its life. I can't complain as I got over 6 years out of that battery.
I assume the digital clock that stays on all the time could be a "parasitic draw" couldn't it? I wouldn't think it would be enough to drain the battery down .7 volts over 5 days though would it?
Could someone walk me through putting the ammeter inline with the + cable? I'd like to learn something.
If you can get a DC clamp-on ammeter that would be easier, as you just clamp it around the + or - cable. I have an AC one, unsure about the DC ones. If not the ammeter will have 2 connections. Remove the + or - from the battery and clip it to one of the connections and clip the battery to the other. Some DMMs can do this also. Remember this setup is to check very light loads. Even your headlights would be to big a current draw. You can pull fuses to check. If you connect it backwards do not worry it will work either way. If its an analog one, then 0 amps will be center scale.
You mention a rebuilt alternator. Is it possible someone did the alternator wrong, swapped the sense and excite wires? Could be inside the alternator or how its wired outside. If those wires are swapped the alternator will work fine and charge, but will drain the battery when the engine is off.
The alternator was rebuilt professionally at reputable shop but I suppose everyone does make mistakes on occasion. Maybe someone can tell me how to test that as well with an ammeter.
I have a Craftsman digital ammeter with the probe type ends....they do not clip on.
I want to make sure I'm doing this correctly so here is where I'm at. I pulled the battery out this morning and charged it for a few hours at 2 amps again. It was 12.06 volts this morning and 12.85 when I disconnected it 3 hours ago. Before I put it back in the truck it was reading 12.55 volts. I understand the "false reading" someone mentioned in an earlier post so I will check it after 24 hours expires. I hooked up the - battery cable and left the + one unhooked. I turned the ammeter to VDC (volts) and touched the one probe to the + post on the battery and the other probe to + battery cable. I got a reading of -12.55 volts. I then reversed the probes and got the 12.55 volts so it does read both ways as Don mentioned.
Am I doing the test correctly so far? Does this mean I have nothing draining the battery? Do I pull fuses and continue to check the ammeter? Should I turn something on (interior lights or something) and check the ammeter? What is my next step or am I already messing this test up? I apologize for not being the sharpest tool in the shed. Thanks for all the help thus far.
Scott
I have a Craftsman digital ammeter with the probe type ends....they do not clip on.
I want to make sure I'm doing this correctly so here is where I'm at. I pulled the battery out this morning and charged it for a few hours at 2 amps again. It was 12.06 volts this morning and 12.85 when I disconnected it 3 hours ago. Before I put it back in the truck it was reading 12.55 volts. I understand the "false reading" someone mentioned in an earlier post so I will check it after 24 hours expires. I hooked up the - battery cable and left the + one unhooked. I turned the ammeter to VDC (volts) and touched the one probe to the + post on the battery and the other probe to + battery cable. I got a reading of -12.55 volts. I then reversed the probes and got the 12.55 volts so it does read both ways as Don mentioned.
Am I doing the test correctly so far? Does this mean I have nothing draining the battery? Do I pull fuses and continue to check the ammeter? Should I turn something on (interior lights or something) and check the ammeter? What is my next step or am I already messing this test up? I apologize for not being the sharpest tool in the shed. Thanks for all the help thus far.
Scott
2 amps will take at least four days to charge. You're seeing a "surface charge".
Before messing around too much I'd take it to walmart for a free test; in my experience their testing equipment is very fair and will flunk a marginal battery.
Their yellow batteries are not usually duds, but you might have gotten one from when Exide made them. Those are doorstop worthy.
I found this chart but have to disagree with it; I feel 12.2 volts is about 25% charged.
Before messing around too much I'd take it to walmart for a free test; in my experience their testing equipment is very fair and will flunk a marginal battery.
Their yellow batteries are not usually duds, but you might have gotten one from when Exide made them. Those are doorstop worthy.
I found this chart but have to disagree with it; I feel 12.2 volts is about 25% charged.
To check for parasitic drain, you need to have your meter set on amps (milliamps), NOT volts. It should be below a certain number with the key off and EVERYTHING off (trunk lights, etc.). Some cars will have a higher draw, then go into sleep mode.
Google "diagnose battery parasitic drain" for instructions and average milliamp drain expected for modules (computers, clock, etc..).
They will also tell how to pull fuses while the amp reading is taken to diagnose which circuit is draining.
Google "diagnose battery parasitic drain" for instructions and average milliamp drain expected for modules (computers, clock, etc..).
They will also tell how to pull fuses while the amp reading is taken to diagnose which circuit is draining.
youtube also has many tutorials on auto diagnosis and repairs. It has saved me several times when working with something odd....i.e., someone elses light bulb replacement.
With the ammeter set on milliamps I get a reading of 2.22 on "auto" which I am assuming is minimal amperage draw. That should convert to .00222 amps. After googling as suggested I found that under .035 amps is normal. I'm charging the battery for a few days on 10 amp and will go from there. If it drains down again I'm taking it to Wal Mart and letting them test it. Thanks again for all the help.
the "false charge" is known as a "surface charge".
A fully charged car battery (valve regulated lead-acid VRLA) is 12.65 volts at 70F or 80F ambient temperature. If it's colder then 100% state of charge will be slightly lower like around 12.62 or 12.60 volts. When you're down around 12.50 to 12.40 volts the battery is near 50% state of charge.
If possible charge the battery overnight or for 6-8 hours at 2amp setting but not higher than 2amp. Then let the battery sit not connected to anything for 8-12 hours to get rid of the surface charge. What you can do is put the battery on charge in the evening then take it off first thing in the morning before leaving the house, then measure the voltage on it that evening which should be > 10 hours later. You are measuring "open-circuit voltage" on the battery, which means voltage across the positive + and negative - terminals with them not connected to anything. You should see around 12.65 volts on a digital multimeter. All batteries self discharge over time, so to know whether you have a bad battery is you have to let it sit a day or two then remeasure open circuit voltage and see how much it dropped. Over a week it should not drop more than around 0.02 volts, as long as the ambient temperature did not change much, you should still be over 12.60 volts. if open circuit voltage dropped significantly then that's a good indication the battery is bad.
A fully charged car battery (valve regulated lead-acid VRLA) is 12.65 volts at 70F or 80F ambient temperature. If it's colder then 100% state of charge will be slightly lower like around 12.62 or 12.60 volts. When you're down around 12.50 to 12.40 volts the battery is near 50% state of charge.
If possible charge the battery overnight or for 6-8 hours at 2amp setting but not higher than 2amp. Then let the battery sit not connected to anything for 8-12 hours to get rid of the surface charge. What you can do is put the battery on charge in the evening then take it off first thing in the morning before leaving the house, then measure the voltage on it that evening which should be > 10 hours later. You are measuring "open-circuit voltage" on the battery, which means voltage across the positive + and negative - terminals with them not connected to anything. You should see around 12.65 volts on a digital multimeter. All batteries self discharge over time, so to know whether you have a bad battery is you have to let it sit a day or two then remeasure open circuit voltage and see how much it dropped. Over a week it should not drop more than around 0.02 volts, as long as the ambient temperature did not change much, you should still be over 12.60 volts. if open circuit voltage dropped significantly then that's a good indication the battery is bad.
for checking for parasitic drain when the truck is off, have the battery fully charged and whether it has a surface charge (it just got done being charged) or not does not matter.
have your digital multimeter with the positive lead connected to the amp hole on the meter and set it to milliamp scale. This is usually fused in the multimeter to around 400 milliamps. Because of this, you'll need a jumper wire that will connect from battery + post to the trucks red battery cable that goes to the battery. You need to make this connection first without using the multimeter because when you make the connection and you'll notice a small arc when you do, this is a high current spike of a few amps because the engine computer, body control module, alarm system, and stereo system are first being powered up. After a few seconds the current draw from the battery will drop down to less than 100 milliamps, which you can measure with your multimeter,,, if you make the connection with the multimeter first you'll blow the fuse in it when the meter is on the milliamp scale. So if you can grab a foot long piece of wire 18-14 gauge in size, and use alligator clips which can be gotten from radio shack for $2.
#1 alligator clip to truck battery positive cable making sure it never touches metal,
#2 other aligator clip to battery +, will get small arc and truck will have battery power.
#3 wait 10 seconds for current to settle before hooking up multimeter
#4 connect red lead from multimeter to battery +
#5 connect black lead from multimeter to truck red cable where alligator clip currently is
#6 disconnect jumper wire with alligator clips so all current is going through multimeter, you should see less than 10 milliamps. I measure 8mA on my LS1 in my 02 camaro. if you have over 50mA then you have a draw, which can be various things most notably the stereo, body control module, and alternator if it has a bad voltage regulator.
have your digital multimeter with the positive lead connected to the amp hole on the meter and set it to milliamp scale. This is usually fused in the multimeter to around 400 milliamps. Because of this, you'll need a jumper wire that will connect from battery + post to the trucks red battery cable that goes to the battery. You need to make this connection first without using the multimeter because when you make the connection and you'll notice a small arc when you do, this is a high current spike of a few amps because the engine computer, body control module, alarm system, and stereo system are first being powered up. After a few seconds the current draw from the battery will drop down to less than 100 milliamps, which you can measure with your multimeter,,, if you make the connection with the multimeter first you'll blow the fuse in it when the meter is on the milliamp scale. So if you can grab a foot long piece of wire 18-14 gauge in size, and use alligator clips which can be gotten from radio shack for $2.
#1 alligator clip to truck battery positive cable making sure it never touches metal,
#2 other aligator clip to battery +, will get small arc and truck will have battery power.
#3 wait 10 seconds for current to settle before hooking up multimeter
#4 connect red lead from multimeter to battery +
#5 connect black lead from multimeter to truck red cable where alligator clip currently is
#6 disconnect jumper wire with alligator clips so all current is going through multimeter, you should see less than 10 milliamps. I measure 8mA on my LS1 in my 02 camaro. if you have over 50mA then you have a draw, which can be various things most notably the stereo, body control module, and alternator if it has a bad voltage regulator.
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Thanks so much for the step by step process to checking for parasitic drain. I did not use a jumper wire but instead hooked my ammeter up direct. I got 2.22 mA and may have been lucky not to blow a fuse in it. Not sure if my 98 Silverado would have a high spike at power up or not.
I took the battery back to Wal Mart tonight to have them test it but all the mechanics were already gone. They just wanted to exchange it at the Customer Service desk and sent me back for a different battery. I tested it when I got home and it is at 12.60 volts. If I did the parasitic load test correctly it should have been a bad battery. I'm going to do the test again with this new battery and if all is fine I will hook it up and go. I'll be watching the old voltmeter gauge on the dash pretty closely though!!
I took the battery back to Wal Mart tonight to have them test it but all the mechanics were already gone. They just wanted to exchange it at the Customer Service desk and sent me back for a different battery. I tested it when I got home and it is at 12.60 volts. If I did the parasitic load test correctly it should have been a bad battery. I'm going to do the test again with this new battery and if all is fine I will hook it up and go. I'll be watching the old voltmeter gauge on the dash pretty closely though!!
Dash voltmeters are not known to be super accurate. Best to check with a DVM. But you can use your dash gauge to see if the voltage jumps up by about 1.5V when the engine is running.
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