battery drain?

[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 longshot270

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

Yup, that's one that came to mind. We try to keep things a bit more civil on f150Online.com though. And I'm the "liberal" moderator there! Here, there's nothing to do as a moderator!

Originally Posted by longshot270

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.

I think if you saw a "resting state battery" - disconnected from ALL draws and not connected to a charger for a couple of days showing below 12.4 V, I'd think it had a problem - possibly an internal short or so badly sulphated it couldn't take a full charge.

My "Battery Maintainer Plus" says a battery in the "grey" area CAN be revived though desulphation.

One thing I thought was interesting though in the link I posted last time was that an alternator is NOT a battery "charger" - it's more a battery maintainer. If you need to charge a battery, do NOT use the alternator to do it!

- Jack

[Longshot270]

Well we usually delt with grime covered batteries out of farm equipment. I can only remember a few cases that needed a battery on the spot where the vehicle was running on a dead battery that had seen regular use. But other than those few special cases, if they hadn't said they charged the battery the day before we would ask them to try it before buying a new one. It was suprising how many lasted for a few more months and you could tell those old ranchers were happy they tried it. Really helped boost customer brownie points for the younger guys compared to the leaders and managers who were always trying to sell the most expensive of everything.

[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

[Jackpine]

Originally Posted by longshot270

Well we usually delt with grime covered batteries out of farm equipment. I can only remember a few cases that needed a battery on the spot where the vehicle was running on a dead battery that had seen regular use. But other than those few special cases, if they hadn't said they charged the battery the day before we would ask them to try it before buying a new one. It was suprising how many lasted for a few more months and you could tell those old ranchers were happy they tried it. Really helped boost customer brownie points for the younger guys compared to the leaders and managers who were always trying to sell the most expensive of everything.

Yup! I've gotten several more months out of a weak battery too, by charging it with a CHARGER, not the alternator. It's certainly worth a try, isn't it?

- Jack

[Longshot270]

I think most people have a hard time understanding all the different terms and laws for electricity. I've never had trouble but then again I played with my dad's multimeter a long time before I ever got anything like a game boy or computer. I have also been hit by just about every voltage in america. lol

[Jackpine]

Originally Posted by longshot270

I think most people have a hard time understanding all the different terms and laws for electricity. I've never had trouble but then again I played with my dad's multimeter a long time before I ever got anything like a game boy or computer. I have also been hit by just about every voltage in america. lol

THAT may explain a few things!

- Jack