Why is my battery voltage higher than its rating?
It is completely normal for a battery to have an open-circuit (no load) voltage higher than its rated voltage. There is no way to tell from that whether it is fully charged, half charged, etc. We can only say that it is not fully discharged. The cycle use and standby use voltages are the voltages that the battery charger needs to apply across the battery for rapid charging and standby charging respectively.
Why do the inverter shows low battery even when it's fully charged?
Battery is the backbone of an Inverter. Therefore regular maintenance and care of the battery is very crucial. It is very important that you use correct battery as per requirement. Now, I came to the point if a power inverter carries a built-in charger with reasonably low switch over time from external power source to backup batteries, it acts as a UPS. Manufacturers who sell Power Inverters and UPS’ under two different categories provide built-in batteries for UPS which are packed inside the enclosure. But no batteries are provided with Power Inverters and consumers are allowed to connect them to desired size batteries of their choice. For more indetail regarding the issue I also need to study in more depth.
What’s wrong with the car when you disconnect the battery while the car is running, and turn on the headlights, and the car dies?
The idle speed may be low. The problem is not voltage regulation because the alternator is triphasé so the voltage should not dip to zero between cycles.The head lights draw 10 amps, 120 watts. A well designed system could depend on the battery for providing voltage regulation. You can hear the motor revolution increase a few seconds after turning on the headlights, defrost, etcThis new idle speed is chosen to allow the alternator to exceed 14.4 volts. The alternator is then free to module the excitation current in the stator to regulate the voltage.Beside the extra 10 amps for the head lights, it is expected that the batteries draw some current to recharge, regain the lost energy.Using a scope or a paper plotter or an analog voltmeter (with galvanomètre), the expected behavior when turning on head lights is:Voltage drop very fast from 14.4 volt to 12.0 voltVoltage slowly increase back to 14.4 volt over 3 secondsThe current shape on a scope would be more complicated. It would jump to about 200 amps for about 100 micro second then fall to about 20 amps. It would then slowly fall toward 12 amps over many minutes.I disagree with most answers that claim something is wrong with the alternator or the ignition.This car is behaving as expected. The head lights, like any incandescent lamp, draw 15 times more current when cold, so no computer can remain active without the help of a strong accumulator.Since 1999, every new car use a computer to fire the spark plugs.
My 2004 Chevy Trailblazer DIC message reads "battery not charging"?
It won't hurt to drive it to a repair shop. Did you replace the battery after testing, or did you just throw away the one that was there with no idea of it's condition? Assuming your power steering still works (if it failed, too I would think failed drive belt), it's almost certainly the alternator. A good rebuilt one costs around $135, and a person with a few hand tools could change it out in half an hour. A repair shop should charge around $250 - $300, including parts and labor. If you have a voltmeter, check the voltage across the battery posts -- should read about 12.0 - 12.6 vdc. With motor running, should read about 14.4. If voltage is lower running than off, faulty alternator is strongly indicated.
How long do you have to drive your car to recharge the battery?
Curiously, of all answers so far, no one has shown the physics. This starts from the battery’s charge capacity, which is measured in Amp-hours.A typical car battery has 50 Amp-hour capacity. This means from completely dead to fully charged, requires a product of current (in Amps) times time (in hours) of somewhat more than 50. You need more, because of charging inefficiencies.A typical charging system can have 60 Amps left over after supplying headlights and the needs of the engine, so it will take about an hour of driving, provided you are smart enough to leave optional equipment like heater fan, seat warmers, whatever, OFF. If not, it may take 2 or more hours; if you expect the battery to get back up to snuff while you have all your electrical accessories running, you’ll be disappointed.Lastly, if your battery is oldish like 5 years or so, it won’t have the capacity that it had new. Perhaps only half that capacity, or less. In that case, it will come up to “full charge” sooner, but that’s not a good thing: it will also go dead sooner.