So I had new Delco batteries installed in the Mountaineer and the Aerostar on the same day. Next morning the Aerostar is sitting there at 12.6 volts, but the Mountaineer is at 12.3. Is it all that carp on the Mountaineer that keeps the battery depressed? Is it possible that all the carp that runs off the Mountaineer battery when it is shut off causes a 12.6 volt battery to read lower, that is, will a drain on the battery depress the voltage reading from the true value? Are these modern cars simply hard on batteries? I sat in the Mountaineer and ran the radio for an hour and then the battery read 12.1! At what voltage will it not start? I understood that 12.6 is fully charged and that somewhere like 12.0 is pretty bad.
Batteries and Modern Cars
- Thread starter TallPaul
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Paul: Did you have a baseline voltage to start this test? Maybe one battery was not 100% charges.
Plus, I've been told that it takes a few cycles (charge/discharge) for the battery to hit it's peak performance level. Check it in a week.
I suggest that you measure the current draw, and you will know for sure. Wait 1/2 hour or more. Loosen the negative terminal clamp at the battery. Connect working milliamp meter between chassis and the negative post on the battery. (clamp one side. Hold the other in place.)
Lift the negative clamp while maintaining contact between the battery terminal and the meter. This will take care. Read the load. Put the clamp back into place, and tighten it.
I looked at several Youtube videos on measuring parasitic draw on a car battery, but I did not see one that showed the technique of maintaining voltage to the car through the meter during the process. That is the tricky part.
If you lose power, then you may have to reset your radio, plus there may be some loads that come on for only a while after battery voltage gets restored.
This process would be much easier using a replacement battery that has both top and side terminals.
Lift the negative clamp while maintaining contact between the battery terminal and the meter. This will take care. Read the load. Put the clamp back into place, and tighten it.
I looked at several Youtube videos on measuring parasitic draw on a car battery, but I did not see one that showed the technique of maintaining voltage to the car through the meter during the process. That is the tricky part.
If you lose power, then you may have to reset your radio, plus there may be some loads that come on for only a while after battery voltage gets restored.
This process would be much easier using a replacement battery that has both top and side terminals.
I think the Mountaineer has a problem. When I bought it last May it had a new battery in it, albeit, a carpy ValueCraft. A month later the alternator went out. After that the ValueCraft showed one cell with only 3 of 4 balls floating (I know, cheezy cheap hydrometer), so I switched the 4 year old 72-month battery out of the Aerostar and into the Mountaineer as it tested good and was 750 cca vs the ValueCraft 650. Then last week I had a no start. Battery tested 11.9, put on trickle for an hour or so and it showed 12.6, would then crank but not start. Towed in and shop said it was flooded. Their tester showed the battery was no good, so we replaced it. And that got me to my original post. Anyway, I can check it again since the battery was put in last Friday. Oh, I better leave the hood open because opening the door on these new fangled things sets off all kinds of electonic stuff from puddle lights to computer who knows what. Thanks.
Originally Posted By: Carbon
I suggest that you measure the current draw, and you will know for sure. Wait 1/2 hour or more. Loosen the negative terminal clamp at the battery. Connect working milliamp meter between chassis and the negative post on the battery. (clamp one side. Hold the other in place.)
Excellent suggestion. I recently read about that, but your idea to attach the meter before disconnecting the clamp is great! I have the easy clamps, like a steel band around the top terminal. I'll get my son to help. Shut off half hour with hood left open will measure true drain. I'll see if I can do it tonight and post results here. Thanks!
I suggest that you measure the current draw, and you will know for sure. Wait 1/2 hour or more. Loosen the negative terminal clamp at the battery. Connect working milliamp meter between chassis and the negative post on the battery. (clamp one side. Hold the other in place.)
Excellent suggestion. I recently read about that, but your idea to attach the meter before disconnecting the clamp is great! I have the easy clamps, like a steel band around the top terminal. I'll get my son to help. Shut off half hour with hood left open will measure true drain. I'll see if I can do it tonight and post results here. Thanks!
Better is a clamp on ammeter.
All my work vehicles suffer from the Eating battery syndrome. I think the only way to prevent a battery from eventually draining is to disconnect it from the vehicle. I heard that all starters and alternators and all other devices connected to your battery will have a slight parasitic draw. I once saw a chart that had some numbers on it. I bet that f-150 you got has none or next to no problems. I got a 94 with a I6 and it has been the best truck i have ever owned. I also dont think one battery that is rated the same as the next battery will have the exact same specs and what not, giving you a different result when testing.
Things are not stable yet.
And even if they were, slight differences in each battery [even if they are the same] can account for voltage variances.
Same for temperature - it would be tough to get each on exactly the same before measuring voltage. Alternator/regulator variances will also net different voltage.
But a current draw will show you what each is eating when at rest.
BTW, a good manual charge is a great idea for a new battery.
And even if they were, slight differences in each battery [even if they are the same] can account for voltage variances.
Same for temperature - it would be tough to get each on exactly the same before measuring voltage. Alternator/regulator variances will also net different voltage.
But a current draw will show you what each is eating when at rest.
BTW, a good manual charge is a great idea for a new battery.
Ford recommends 50ma or less current draw. This is after waiting about an hour (ignition off), for the computer systems to sleep. If you open a door or whatever during that time, you will have to start over.
We do it quite a bit chasing gremlins on light bars, sirens, dash cams, etc on our CVPI. I use a small vice grip (needle nose) to clamp on the negative clamp, then a alligator jumper clip to attach to the probe and clip the other on the vice grip release.
Dave
We do it quite a bit chasing gremlins on light bars, sirens, dash cams, etc on our CVPI. I use a small vice grip (needle nose) to clamp on the negative clamp, then a alligator jumper clip to attach to the probe and clip the other on the vice grip release.
Dave
I have a clamp on amp meter, but not sure if it goes on 12V system, will check. That would be much easier.
Yeah and the doors get opened and shut a lot, that alone could be a heavy tax on the battery.
The Aerostar seems pretty good on batteries, can't tell with F150 as it is 5 years into a 6 year battery--time for a new one on that too, and I guess the motorhome is due.
I read about the auto industry was looking at going to 42 volt batteries because of all the electronic carp on cars these days.
But I do love the hand crank windows in the F150 and manual locks etc. I think my next vehicle should be a restored oldie. The under hood on 1960s cars is beautiful, you can see the engine and there are only a few wires besides the spark plug wires.
Yeah and the doors get opened and shut a lot, that alone could be a heavy tax on the battery.
The Aerostar seems pretty good on batteries, can't tell with F150 as it is 5 years into a 6 year battery--time for a new one on that too, and I guess the motorhome is due.
I read about the auto industry was looking at going to 42 volt batteries because of all the electronic carp on cars these days.
But I do love the hand crank windows in the F150 and manual locks etc. I think my next vehicle should be a restored oldie. The under hood on 1960s cars is beautiful, you can see the engine and there are only a few wires besides the spark plug wires.
Originally Posted By: TallPaul
But I do love the hand crank windows in the F150 and manual locks etc.
Same here, even though it's not an F-150.
But I do love the hand crank windows in the F150 and manual locks etc.
Same here, even though it's not an F-150.
Originally Posted By: dailydriver
Originally Posted By: TallPaul
But I do love the hand crank windows in the F150 and manual locks etc.
Same here, even though it's not an F-150.
I bought a ratty old 94 Ranger this summer. The radio is busted, it has no AC, crank windows and a 5spd. It reminds me of my Willys Overland wagon only better. It has a certain Je ne sais quois about its patches and flaws.
Originally Posted By: TallPaul
But I do love the hand crank windows in the F150 and manual locks etc.
Same here, even though it's not an F-150.
I bought a ratty old 94 Ranger this summer. The radio is busted, it has no AC, crank windows and a 5spd. It reminds me of my Willys Overland wagon only better. It has a certain Je ne sais quois about its patches and flaws.
Okay, with the hood left open and an hour after the last time it's brain was disturbed by a door opening, it tested 125 mA. That is a bit high, but I would not think enough to be a problem. Also, the battery did test 12.59, so I think it's the stuff drawing off the battery in the 20+ minutes after the door is opened that is causing the lower battery reading.
Originally Posted By: andyd
I bought a ratty old 94 Ranger this summer. The radio is busted, it has no AC, crank windows and a 5spd. It reminds me of my Willys Overland wagon only better. It has a certain Je ne sais quois about its patches and flaws.
I would love it, although I might miss my air conditioning. My son will be driving soon and wants just about that kind of a truck, S-10, Sonoma, Ranger, or other like vehicle. He will even take power acessories, but it MUST have a manual transmission!
Originally Posted By: andyd
I bought a ratty old 94 Ranger this summer. The radio is busted, it has no AC, crank windows and a 5spd. It reminds me of my Willys Overland wagon only better. It has a certain Je ne sais quois about its patches and flaws.
I would love it, although I might miss my air conditioning. My son will be driving soon and wants just about that kind of a truck, S-10, Sonoma, Ranger, or other like vehicle. He will even take power acessories, but it MUST have a manual transmission!
Originally Posted By: Donald
Better is a clamp on ammeter.
Your typical clamp on ammeter is for AC only, I think. At least that used to be the case. Now they can make more sophisticated clamp-on devices that could measure DC with maybe hall sensors, the classic acts like a transformer; it only works with AC.
Better is a clamp on ammeter.
Your typical clamp on ammeter is for AC only, I think. At least that used to be the case. Now they can make more sophisticated clamp-on devices that could measure DC with maybe hall sensors, the classic acts like a transformer; it only works with AC.
Originally Posted By: TallPaul
Okay, with the hood left open and an hour after the last time it's brain was disturbed by a door opening, it tested 125 mA. That is a bit high, but I would not think enough to be a problem. Also, the battery did test 12.59, so I think it's the stuff drawing off the battery in the 20+ minutes after the door is opened that is causing the lower battery reading.
Originally Posted By: andyd
I bought a ratty old 94 Ranger this summer. The radio is busted, it has no AC, crank windows and a 5spd. It reminds me of my Willys Overland wagon only better. It has a certain Je ne sais quois about its patches and flaws.
I would love it, although I might miss my air conditioning. My son will be driving soon and wants just about that kind of a truck, S-10, Sonoma, Ranger, or other like vehicle. He will even take power acessories, but it MUST have a manual transmission!
Paul,
125ma is not too bad. Most of your drain will come with doors opening, keyless entry, etc. Technology comes with a price, I guess.
We have a 62 Bel Air that is used as a parade car. What a pleasure to work on. No A/C, manual everything. Cold natured beast, but love listening to that 327 wake up!
Dave
Okay, with the hood left open and an hour after the last time it's brain was disturbed by a door opening, it tested 125 mA. That is a bit high, but I would not think enough to be a problem. Also, the battery did test 12.59, so I think it's the stuff drawing off the battery in the 20+ minutes after the door is opened that is causing the lower battery reading.
Originally Posted By: andyd
I bought a ratty old 94 Ranger this summer. The radio is busted, it has no AC, crank windows and a 5spd. It reminds me of my Willys Overland wagon only better. It has a certain Je ne sais quois about its patches and flaws.
I would love it, although I might miss my air conditioning. My son will be driving soon and wants just about that kind of a truck, S-10, Sonoma, Ranger, or other like vehicle. He will even take power acessories, but it MUST have a manual transmission!
Paul,
125ma is not too bad. Most of your drain will come with doors opening, keyless entry, etc. Technology comes with a price, I guess.
We have a 62 Bel Air that is used as a parade car. What a pleasure to work on. No A/C, manual everything. Cold natured beast, but love listening to that 327 wake up!
Dave
In the past I might have recommended you get one of those battery post switches that allows you to disconnect the battery quickly if you plan on parking it overnight, but with a modern vehicle I'm not sure if that would mess up the computers. One possibility might be to just seek out the biggest capacity battery you can squeeze in there--even in the same case size there will be differences in capacity between different brands and grades of battery. There's always a trickle charger.
The manual (Haynes I think) says 100 mA is normal, but that higer numbers such as approximately 500 mA will drain the battery. Well 100 mA will drain it if you don't drive it for long enough. Oh, I don't recall the manual instructing to wait an hour before the test.
I did discover that if you disconnect the cable, then hook up the meter you will blow the 500 mA fuse. Apparently when the connection is made a lot of power flows into something (kind of like an electric motor starting up), so I had to connect the meter and then remove the cable to get the reading.
I did discover that if you disconnect the cable, then hook up the meter you will blow the 500 mA fuse. Apparently when the connection is made a lot of power flows into something (kind of like an electric motor starting up), so I had to connect the meter and then remove the cable to get the reading.
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