Electrical Question Amps and Volts ?
Thread Starter
Burning Brakes
Joined: Jul 2005
Posts: 836
Likes: 89
From: Tucson Az
2017 C7 of Year Finalist
Electrical Question Amps and Volts ?
I checked my amp drain today and it is at .03 I guess that is normal. My question is how long does it take for a .03 amp drain to drop a 12 volt battery from 12 volts to 11 volts. Is ther a formula to determine this?
Ron
Ron
Melting Slicks
Joined: Jul 2006
Posts: 2,332
Likes: 31
From: Silver Spring MD
Volts and Amps
Electricity is often described by its analogy to water.
Voltage is the potential or electrical pressure which is similar to water pressure in pounds per square inch or other measure. If you have a tank that is 12 feet deep the pressure at the bottom is higher than if the tank was only 6 foot deep. SOOOOOOOOOOOOOOOO
12 Volts is greater than 6 Volts.
Amperage is the amount or quantity of electrons flowing. Like a 10 inch pipe at the bottom of the 12 foot tank can supply more flow per second than a 5 inch pipe at the same location. SOOOOOOOOOOOOOOOO
10 Amps is much more current flow than 5 Amps.
Voltage is often described as what kills you but it is really the AMPERAGE or current flowing that does. You can create a static electric generator which produces millions of volts but if there is no real current flow you won't get fried.
Hope that helps your understanding.
BIGHANK
Voltage is the potential or electrical pressure which is similar to water pressure in pounds per square inch or other measure. If you have a tank that is 12 feet deep the pressure at the bottom is higher than if the tank was only 6 foot deep. SOOOOOOOOOOOOOOOO
12 Volts is greater than 6 Volts.
Amperage is the amount or quantity of electrons flowing. Like a 10 inch pipe at the bottom of the 12 foot tank can supply more flow per second than a 5 inch pipe at the same location. SOOOOOOOOOOOOOOOO
10 Amps is much more current flow than 5 Amps.
Voltage is often described as what kills you but it is really the AMPERAGE or current flowing that does. You can create a static electric generator which produces millions of volts but if there is no real current flow you won't get fried.
Hope that helps your understanding.
BIGHANK
Drifting
Joined: Oct 2003
Posts: 1,923
Likes: 5
From: San Antonio TX
Electricity is often described by its analogy to water.
Voltage is the potential or electrical pressure which is similar to water pressure in pounds per square inch or other measure. If you have a tank that is 12 feet deep the pressure at the bottom is higher than if the tank was only 6 foot deep. SOOOOOOOOOOOOOOOO
12 Volts is greater than 6 Volts.
Amperage is the amount or quantity of electrons flowing. Like a 10 inch pipe at the bottom of the 12 foot tank can supply more flow per second than a 5 inch pipe at the same location. SOOOOOOOOOOOOOOOO
10 Amps is much more current flow than 5 Amps.
Voltage is often described as what kills you but it is really the AMPERAGE or current flowing that does. You can create a static electric generator which produces millions of volts but if there is no real current flow you won't get fried.
Hope that helps your understanding.
BIGHANK
Voltage is the potential or electrical pressure which is similar to water pressure in pounds per square inch or other measure. If you have a tank that is 12 feet deep the pressure at the bottom is higher than if the tank was only 6 foot deep. SOOOOOOOOOOOOOOOO
12 Volts is greater than 6 Volts.
Amperage is the amount or quantity of electrons flowing. Like a 10 inch pipe at the bottom of the 12 foot tank can supply more flow per second than a 5 inch pipe at the same location. SOOOOOOOOOOOOOOOO
10 Amps is much more current flow than 5 Amps.
Voltage is often described as what kills you but it is really the AMPERAGE or current flowing that does. You can create a static electric generator which produces millions of volts but if there is no real current flow you won't get fried.
Hope that helps your understanding.
BIGHANK
this should have put all of your questions to bed 
BTW .03 amp will take a long time to draw down a good battery, most car batterys are some where around 50 amp hours at the 1 amp rate (it takes 50 hours at 1 amp to total discharge the battery). I would need to know the discharge curve of the battery in question but below 11 volts open circuit is around 75% discharged (just off the cuff) hope that helps.
More Than Zero
Thread Starter
Burning Brakes
Joined: Jul 2005
Posts: 836
Likes: 89
From: Tucson Az
2017 C7 of Year Finalist
this should have put all of your questions to bed BTW .03 amp will take a long time to draw down a good battery, most car batterys are some where around 50 amp hours at the 1 amp rate (it takes 50 hours at 1 amp to total discharge the battery). I would need to know the discharge curve of the battery in question but below 11 volts open circuit is around 75% discharged (just off the cuff) hope that helps.
More Than Zero
Ron
Melting Slicks
Joined: Jul 2006
Posts: 2,332
Likes: 31
From: Silver Spring MD
Parasitic discarge nowadays
I was amazed to find that my brand new Taurus with the heated windshield and 900 AH battery was dead after only the dome light was left on OVERNIGHT. Car was only a few months old but battery was completely dead with just one bulb left on overnight.
Also with normal batteries that have removable vent caps the sulphuric acid can coat the top of the battery with a very thin layer of conductive acid. This acts like a resistor and will also discharge the battery if left uncharged for a long period. Solution to this one. Boric acid and water and a rag wiped over the top to neutralize the acid. Then carefully pour it over the battery being careful NOT to get any into the filler holes
BIGHANK
Le Mans Master
Joined: Sep 2004
Posts: 5,707
Likes: 4
From: Los Angeles
If you're only getting a week to 10 days, you have a bad battery or you're drawing more than .03 amps. That is NOT normal. I have left my car for more than 2 months with no problems.
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Thread Starter
Burning Brakes
Joined: Jul 2005
Posts: 836
Likes: 89
From: Tucson Az
2017 C7 of Year Finalist
[QUOTE=robvuk;1562629138]If you're only getting a week to 10 days, you have a bad battery or you're drawing more than .03 amps. That is NOT normal. I have left my car for more than 2 months with no problems.[/QUOTE
The battery may be getting weak. I have a 2 year old exide orbital. Its either that or it may be that I don't drive the car enough. I only drive it a couple of days a week and then for only a few miles. Before you say it I have another vet I put the miles on.
Ron
The battery may be getting weak. I have a 2 year old exide orbital. Its either that or it may be that I don't drive the car enough. I only drive it a couple of days a week and then for only a few miles. Before you say it I have another vet I put the miles on.
Ron
Le Mans Master
Joined: Feb 2002
Posts: 6,937
Likes: 21
From: Waldorf MD
It is not unusual for a C5 battery to go dead in 2 weeks of no use. I have a 6 year old Exide Orbital battery and if I know I'm not going to drive it for 3 days or more, I put a battery maintainer on it (charging at 1 amp and floating when battery is fully charged). This is rare for me, as it is a daily driver, 1998 with over 109,000 miles.
BTW a 12-volt battery will measure at about 12.9 volts when it’s fully charged and about 11.4 volts when it is fully discharged. Although a load test on a battery is the only true way to measure if it is good, most anyplace that sells batteries will do one for free.
BTW a 12-volt battery will measure at about 12.9 volts when it’s fully charged and about 11.4 volts when it is fully discharged. Although a load test on a battery is the only true way to measure if it is good, most anyplace that sells batteries will do one for free.
Last edited by Oldvetter; Nov 6, 2007 at 08:47 PM.
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
Remember the "old days" ????
Turn the key to OFF and EVERY item in the car was OFF .... the radio died, the interior lamps only worked if the door was open ... but once you had turned off the lights and closed the doors there was NO DRAW on the battery.
Today ... the RFA (the radio receiver for the key fobs) has to stay powered up because it doesn't know if you will return to the car in 20 minutes, or 20 hours, or three days. And the BCM stays powered up because it is the computer that controls the cars security system and so unlocks the doors when the RFA says it got a valid signal.
So, bottom line .... let the car sit for a few days ... no problem... a few weeks ... that could be an issue as the BCM continues to draw the battey down (the BCM commands the RFA to shut down after about 7 days, only the key can unlock the car after that) to a point where there is not enough cranking power in the battery to start the car.
Turn the key to OFF and EVERY item in the car was OFF .... the radio died, the interior lamps only worked if the door was open ... but once you had turned off the lights and closed the doors there was NO DRAW on the battery.
Today ... the RFA (the radio receiver for the key fobs) has to stay powered up because it doesn't know if you will return to the car in 20 minutes, or 20 hours, or three days. And the BCM stays powered up because it is the computer that controls the cars security system and so unlocks the doors when the RFA says it got a valid signal.
So, bottom line .... let the car sit for a few days ... no problem... a few weeks ... that could be an issue as the BCM continues to draw the battey down (the BCM commands the RFA to shut down after about 7 days, only the key can unlock the car after that) to a point where there is not enough cranking power in the battery to start the car.