battery drain?

[Longshot270]

Jack, I bet that the numbers your getting have something to do with the Voltage=Amps/Resistance formula. If the battery tender uses clamps to connect to the battery then it will read more resistance than the vehicle(because the vehicle has been bolted in since day 1). More resistance is going to make the voltage look lower without any higher amps. Could be wrong but it sounded good when it ran through my head.

[RGSMDNR]

ahh ok, thats good to know. Would it matter if the PCM was programmed or stock mode? can someone explain why it draws current while the truck is off?

[Longshot270]

Im not sure having the PCM progarammed would make a difference on the electrical draw. As far as I know the small amount of draw is what lets the computer remember what the latest amounts of data there are. You know when you unplug the battery that you usually lose the radio presets and stuff?(my truck doesn't do it but my dad's does) I think one of the things it remembers is the last driving conditions, I've noticed that some vehicles will throw P1000(?) codes after being reprogrammed or having the battery unplugged. I also think its the same on the gryphon, that small amount of draw lets the programmer remember stuff like your averge MPG and top speeds, that kind of stuff. This part Im not so sure about

[88Racing]

Oh let's see here?
Some examples of current draw while vehicle is off.

KAM. Keep Alive Memory
Security. PATS system.
Remote Start.
Radio memory including clock.
Shut down sequencing procedures when vehicle is turned off.

A battery tender directly bolted to the post clamps may be the best way to combat losses while the truck is sitting. Especially like my garage queen. But if your truck is a daily driver I wouldn't worry about it.

Lars

[Jackpine]

Originally Posted by longshot270

Jack, I bet that the numbers your getting have something to do with the Voltage=Amps/Resistance formula. If the battery tender uses clamps to connect to the battery then it will read more resistance than the vehicle(because the vehicle has been bolted in since day 1). More resistance is going to make the voltage look lower without any higher amps. Could be wrong but it sounded good when it ran through my head.

Longshot - we MAY be talking about two different things. The voltage and amperage numbers I quoted in the other post are with a good digital multimeter. The parasitic draw in my truck is definitely 0.05 amps (50 ma) after the truck has been sitting in a "quiet" state - doors closed, everything shutdown for at least one hour. To this list of what Lars posted for current draw, I also have memory for the pedals and seats and memory for the climate control temperature. The King Ranch also has the door open keypad that has to be alive to accept key input and all our trucks probably have a powered receiver to accept signals from the key fob for remote door unlock.

In this post, the 13.9-14.1 volts are being displayed on the Gryphon with the engine running and this seems a pretty normal regulated charging voltage from the alternator.

What I found puzzling, is the state of the battery after driving. I expected it to be at or near a full charge state. But, I think I just figured out why that may not be so. My headlights have the "auto-on" feature, so when I drive into the garage, they come on. They stay on for about 20 seconds after I shutdown too, as do the interior lights after I get out an close the doors. There seems to be some other, less obvious circuits that are alive too, for about 5 minutes, until the battery saver relay opens. This puts a fairly heavy draw on the battery.

By the time I get my battery tender hooked up, it takes about 6-8 hours to reach the fully charged state (since it uses a very low charging current to keep from "boiling" the battery - about 0.2 Amps) when the battery is above an 80% charge state. If I simply unplug the battery tender and then plug it back in again, its operation indicates a full charge within a very short time, since there was no big drain while it was disconnected.

The 0.05 Amp draw from the Gryphon (when it's plugged in) was confirmed with Bill. I know I have a total parasitic draw of 0.1 amps when the Gryphon is installed.

Finally, as Lars said, the Battery Tender comes with a "permanent" plug in connection you can attach to the screw terminals of the battery posts. This makes it simple to use.

- Jack

[Longshot270]

Oh oops, I meant the battery charger was reading low, your older post about parasitic draw sounds good to me. I bought the base model XL with no bells or wistles so I was thinking in terms of my truck. But I'm not so sure the extra bells and whistles would draw 80% if your battery in a short amount of time. I've run my truck's stereo plus a pair of 12 inch subwoofers for over 4 hours at full power and only got knocked down to about 9-10 volts. How many CCA (Cold Cranking Amps) is your battery? If I go with my 540 CCA down to 80%, that would be a loss of 108 amps and drop your battery down to something like 10 or 11 volts. Did I mess up on my math somewhere or use wrong numbers? If you left your lights on for a good while I'd expect to see something like that but it sounds like you hook the battery tender fairly soon after parking. I am pretty sure a single 55 watt bulb is usually around 4-5 amps. We must be arguing somewhere but I'm not sure over what. :nerd:

Question: What is the final voltage after the charger considers the battery to be at 100%?

[Jackpine]

Originally Posted by longshot270

Oh oops, I meant the battery charger was reading low, your older post about parasitic draw sounds good to me. I bought the base model XL with no bells or wistles so I was thinking in terms of my truck. But I'm not so sure the extra bells and whistles would draw 80% if your battery in a short amount of time. I've run my truck's stereo plus a pair of 12 inch subwoofers for over 4 hours at full power and only got knocked down to about 9-10 volts. How many CCA (Cold Cranking Amps) is your battery? If I go with my 540 CCA down to 80%, that would be a loss of 108 amps and drop your battery down to something like 10 or 11 volts. Did I mess up on my math somewhere or use wrong numbers? If you left your lights on for a good while I'd expect to see something like that but it sounds like you hook the battery tender fairly soon after parking. I am pretty sure a single 55 watt bulb is usually around 4-5 amps. We must be arguing somewhere but I'm not sure over what. :nerd:

Question: What is the final voltage after the charger considers the battery to be at 100%?

We're not arguing at all, Longshot! We're having an adult discussion that often doesn't happen in other forums. But, I suspect we may be referring to different things, so there's a bit of misunderstanding.

Let's go back to my total "parasitic" draw of 0.1 amps. This can drain my Costco battery (I can't give you the CCA on it because it's covered by the battery holder cover in the truck and I don't want to disconnect the battery to read the numbers - but I know it's at least 50 CCA above OEM) in about 21 days.

According to the manual that came with my Battery Tender: A battery that is 100% charged should read about 12.9 V in a "resting", no-load state (which is several hours after being disconnected from any kind of charger). If it is fully discharged, the resting voltage will be about 11.4 V. If the output voltage is less than 9 V, it is probably defective.

I have another maintainer I use on my trailer batteries called the BatteryMinder Plus, and it says it only goes into the "maintenance/desulphation" mode when the charging voltage reaches 14 V. (It has to get this high during charging, indicating a lot of "back emf" or "charging resistance" to be at a full charge state).

Now, CCA can be a bit misleading. It refers to cranking ability. It's the number of amps a battery can support for 30 seconds at a temperature of 0 degrees F until the battery voltage drops to unusable levels. It's not the same thing as "cranking amps", which is what you get at 32 degrees F and it's not the same as "reserve capacity", which is more a measure of total power stored.

Here's a good link: http://www.carquest.com/partsBatteryFAQMyths.html#6 It covers many battery facts and myths.

And, back to your point about drain in your post. If I have a 0.1 amp parasitic draw, my Battery Tender, with it's potential 0.2 amp output at an 80%+ charge state is really only delivering 0.1 amps. Pretty puny charging current - but it won't boil the battery, either.

- Jack

[Longshot270]

Originally Posted by JackandJanet

We're not arguing at all, Longshot! We're having an adult discussion that often doesn't happen in other forums. But, I suspect we may be referring to different things, so there's a bit of misunderstanding.

Yeah, kind of strange not having some random person add a comment that doesn't make sence from any but his/her perspective. But it is really refreshing, I can name a couple that I dont like on the fordf150.net

Originally Posted by JackandJanet

According to the manual that came with my Battery Tender: A battery that is 100% charged should read about 12.9 V in a "resting", no-load state (which is several hours after being disconnected from any kind of charger). If it is fully discharged, the resting voltage will be about 11.4 V. If the output voltage is less than 9 V, it is probably defective.

I have another maintainer I use on my trailer batteries called the BatteryMinder Plus, and it says it only goes into the "maintenance/desulphation" mode when the charging voltage reaches 14 V. (It has to get this high during charging, indicating a lot of "back emf" or "charging resistance" to be at a full charge state).

Now, CCA can be a bit misleading. It refers to cranking ability. It's the number of amps a battery can support for 30 seconds at a temperature of 0 degrees F until the battery voltage drops to unusable levels. It's not the same thing as "cranking amps", which is what you get at 32 degrees F and it's not the same as "reserve capacity", which is more a measure of total power stored.

I worked at Tractor Supply Co. for over a year (in high school so I was actually an old timer towards the end. lol) and can pretty much run everything except receiving although I can do some of that. We usually considered a battery fully charged at 12 to 12.6 so it makes sence that I'd be a little off.

[JWBFX4]

Well just to add a little to this.

I have had a good bit of electrical problems a while back (not on truck) and after talking and researching a lot about batteries, everything says that 12.6v is a fully charged battery. Anything above that is considered a "hot charge" Possible the 12.9 volts that your battery maintainer says is where it automatically kicks off to make sure it charged the battery enough

I was always told if the battery is atleast 12.2 volts its in good cranking range anything under that needs charging and if it in the low to mid 11's very possibly bad battery.

[Jackpine]

Originally Posted by JWBFX4

Well just to add a little to this.

I have had a good bit of electrical problems a while back (not on truck) and after talking and researching a lot about batteries, everything says that 12.6v is a fully charged battery. Anything above that is considered a "hot charge" Possible the 12.9 volts that your battery maintainer says is where it automatically kicks off to make sure it charged the battery enough

I was always told if the battery is atleast 12.2 volts its in good cranking range anything under that needs charging and if it in the low to mid 11's very possibly bad battery.

Welcome to the discussion!

I doubt there's any "hard and fast" figure. I'd certainly consider 12.6 V in a resting state battery to be fully charged. And, my manual states that age will cause all readings to drop, but the 1.5 V difference between fully charged and discharged is supposed to be fairly constant.

My experience with batteries seems to support this. And yes, 12.2 V should give you sufficient cranking voltage under normal circumstances. But, it might seem "weak" at that voltage.

Your "hot charge" is what you see on a battery right after disconnecting a charger. There's a "surface charge" that has to dissipate and it takes a few hours to do this if there's no draw. I think it MAY be a capacitive effect.

But, when you have a charger on the circuit delivering over 13 V, it keeps increasing the battery voltage to match. At some point, the charge voltage has to drop off or the battery will be overcharged (boiled). My BatteryMinder says this is 14 V. I know in the maintenance mode, both "maintainers" hold about a 13.5 V state, and according to the manuals, deliver very little Amperage.

Once you disconnect the chargers though, the surface charge (the "hot charge" of 13+ V) bleeds off and the battery settles into its "resting" state. I've honestly never seen 12.9 V here, but 12.7 V seems about right.

One of my trailer batteries suddenly went bad recently, while I was charging it through the onboard, regulated charger. At near full charge, I was used to seeing it draw about 34 Watts at 120 Volts. Suddenly, it spiked to about 96 Watts. I checked the batteries, and one was hot and "gassing". I pulled it out and immediately tested the voltage - it was around 11.2 V. My guess is, it had a shorted cell.

- Jack