What voltage should a car battery be at?
#1
What voltage should a car battery be at?
Hello,
I was wondering what voltage my car should be at? I tried to start it one day and it made some clicking noise as if it's not enough battery charged. I haven't driven my car in a month so I'm guessing the batterie's dead. I charged it and the volt meter shows 13.4 volts. When it's charging and the cars running, it shows 14.5 volts. Is 13.4 volts enough long term or should I buy a new Lexus battery. And if I did buy a new battery and I swapped it out, will disconnecting the battery reset any clock or settings in the car? Thanks...
I was wondering what voltage my car should be at? I tried to start it one day and it made some clicking noise as if it's not enough battery charged. I haven't driven my car in a month so I'm guessing the batterie's dead. I charged it and the volt meter shows 13.4 volts. When it's charging and the cars running, it shows 14.5 volts. Is 13.4 volts enough long term or should I buy a new Lexus battery. And if I did buy a new battery and I swapped it out, will disconnecting the battery reset any clock or settings in the car? Thanks...
#2
Moderator
Search the term battery and you will have lots of advice.
I would start by charging the battery overnight. If it revives then you need not buy a new battery.
Battery are some what a generic part. Since the markup is high at delaership, you would do lot better in buying on your own (unless it being covered by the warranty).
Voltage measurement is typically not a good test for battery. You have to test it under load (free service provided by most places that sell a battery).
If you have every thing preplanned, the swap can be done so quick that you will not loose any setting.
Salim
I would start by charging the battery overnight. If it revives then you need not buy a new battery.
Battery are some what a generic part. Since the markup is high at delaership, you would do lot better in buying on your own (unless it being covered by the warranty).
Voltage measurement is typically not a good test for battery. You have to test it under load (free service provided by most places that sell a battery).
If you have every thing preplanned, the swap can be done so quick that you will not loose any setting.
Salim
#3
I'm suspicious of your voltmeter. With the engine not running, a car battery will have a voltage reading of 12 volts (that's why they call it a 12 volt battery). The normal charging voltage (voltage with engine running) is about 13.6 volts. It could be a little over this, but over 14 volts seems too high to me.
I agree with what Salim wrote too. Driving around for a while (if your charging system is working OK) should give a full battery charge as well as overnight on a battery charger.
My experience is that, unless you use one of the 9-volt battery backup techniques, you will have to reset the clock and maybe some of the memory settings when you disconnect the battery. I guess I'm not as fast as Salim.
My view is that age does matter. If your battery is over 5 years old and you are having any symptoms that point to the battery, I'd be inclined to replace the car battery.
I agree with what Salim wrote too. Driving around for a while (if your charging system is working OK) should give a full battery charge as well as overnight on a battery charger.
My experience is that, unless you use one of the 9-volt battery backup techniques, you will have to reset the clock and maybe some of the memory settings when you disconnect the battery. I guess I'm not as fast as Salim.
My view is that age does matter. If your battery is over 5 years old and you are having any symptoms that point to the battery, I'd be inclined to replace the car battery.
#4
Moderator
Correction .. yes the clock is the only thing that will be reset when you do a quick swap.
Radio, seats and ECU stored information needs a minute or two (not measured).
I am most picky about my seat position so I make sure it is set in the position I like and then disconnect the battery. When I reconnect, I store the last position as mine (without moving the seat). Garage door opener seems not affected by loss of 12v.
One more thing ... please make sure the key is removed from ignition during the whole process. I read some where that the air bag deployed sensor gets activated (may have been SC) better safe than sorry.
Salim
Radio, seats and ECU stored information needs a minute or two (not measured).
I am most picky about my seat position so I make sure it is set in the position I like and then disconnect the battery. When I reconnect, I store the last position as mine (without moving the seat). Garage door opener seems not affected by loss of 12v.
One more thing ... please make sure the key is removed from ignition during the whole process. I read some where that the air bag deployed sensor gets activated (may have been SC) better safe than sorry.
Salim
#5
Thanks everyone. I did charge the battery overnight and everything seems fine. I'll drive it this coming weekend to circulate the oil as well as charging it while driving. The weird thing is. My gas needle was at the half mark. I had an emergency gas tank I just filled last week in the garage so I filled it. I started the car and the needle was still at half. I knew my gas tank was full since I didn't drive it so I drove to the gas station and tried to fill it. It stopped at $1.00 with overspill. I went into the gas station and asked the attendant to look at my car since my needle was at half. He tried pumping gas and gas spilled out. It was full. I asked him to take a look and when he started the car, it was at FULL. Does it have anything to do with the angle of the gas pump resetting the gas needle? Weird...
All in all, car is fully charged and gas is full... Nothing is wrong... Double weird...
All in all, car is fully charged and gas is full... Nothing is wrong... Double weird...
#6
Moderator
There is no calibration for gas. I am assuming that like typical gauge, the float acts like a voltage divider and sends the signal to the gauge. Assuming the battery was weak, the gauge will show less than what the actual level will be.
Having a good battery is now a must for all gauges and sensors.
Salim
Having a good battery is now a must for all gauges and sensors.
Salim
#7
Lexus Champion
I'm suspicious of your voltmeter. With the engine not running, a car battery will have a voltage reading of 12 volts (that's why they call it a 12 volt battery). The normal charging voltage (voltage with engine running) is about 13.6 volts. It could be a little over this, but over 14 volts seems too high to me.
I agree with what Salim wrote too. Driving around for a while (if your charging system is working OK) should give a full battery charge as well as overnight on a battery charger.
My experience is that, unless you use one of the 9-volt battery backup techniques, you will have to reset the clock and maybe some of the memory settings when you disconnect the battery. I guess I'm not as fast as Salim.
My view is that age does matter. If your battery is over 5 years old and you are having any symptoms that point to the battery, I'd be inclined to replace the car battery.
I agree with what Salim wrote too. Driving around for a while (if your charging system is working OK) should give a full battery charge as well as overnight on a battery charger.
My experience is that, unless you use one of the 9-volt battery backup techniques, you will have to reset the clock and maybe some of the memory settings when you disconnect the battery. I guess I'm not as fast as Salim.
My view is that age does matter. If your battery is over 5 years old and you are having any symptoms that point to the battery, I'd be inclined to replace the car battery.
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#8
I stand corrected on some of what you write (ref. http://www.arttec.net/Solar_Mower/4_...20Charging.pdf ). My experience goes back to electro-mechanical voltage regulators, where the upper charging voltage was electro-mechanically limited to around 13.6 volts.
#9
Another reference http://www.buchanan1.net/lead_acid.shtml on battery voltage vs. temperature w/o load.
#10
Lexus Champion
I stand corrected on some of what you write (ref. http://www.arttec.net/Solar_Mower/4_...20Charging.pdf ). My experience goes back to electro-mechanical voltage regulators, where the upper charging voltage was electro-mechanically limited to around 13.6 volts.
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