Alternator Voltage Too Low

If the alternator is charging, you should see a voltage reading between 13. If you get a low voltage reading, like around 12V, then the alternator is the issue. Is this maybe too small to run that far for 140amps?. nationsautoelectric. I took my 2011 Chevy Cruze LT to auto zone and had the alternator tested and since the machine read 15. Suddenly my generator output voltage dropped to around 80 VAC. Voltage Regulator Adjustment Guide By A. Alternator or battery? Last week the warning light for the battery started showing on my way home, I checked the voltage with my ODB gauge right away, and it was showing 10. At higher speed you would prefer a different winding ratio because the voltage can get too high to be useful. So if we somehow fool the regulator into thinking the alternator output voltage is 0. replaced the alternator, 1 week later the battery was too low to start!. Normal voltage output when no accessories are on. However, if your alternator's voltage regulator kept the system voltage at only 12. Then when loads are reduced the battery light goes out. I haven’t set these up yet but they will buzz if the volts go too high like if the voltage. I would take your Alt off and get it checked at a electrical shop that specializes in rebuilding electrical components as they normally have more and better testing equipment than the average mechanic. The CS 144 is easy to rebuild. After I smoked both of those raptor fans due to low voltage within one week, I ditched them for FAL fans that use significantly less current. As you add electrical load by turning on more accessories, the voltage will drop. But then again the battery was a cheap arse factory second so there is also a good chance the battery was a POS. 6V lights and radio and auto temp on. This means that if your battery is too low, you will be unable to start the vehicle and thus you will also be unable to test the alternator, rendering any additional voltmeter-testing totally useless. had it tested at a Advanced Auto Parts. They are usually designated by amperage out put such as a 22- amp or a 32-amp system. If an alternator is overloaded, it may overheat and fail (check for aftermarket sound equipment that may be overloading the stock alternator!). If you're worried about a high amp alternator providing too much power to your ECU, or any other component in your electrical system, you don't need to. However older ( pre maint free battery) cars had a lower charging voltage with 13. (The textbook level for voltage regulator setting with most alternator systems is 14. Too much voltage will damage system components. There's a fairly easy and inexpensive diy fix. Engine running at idle, volts are still around 12. Re: Does my alternator charge battery at low RPM? Contrary to what a lot of folks think, an alternator outputs a voltage/current any time it is turning (if field voltage is present). I recently installed a new voltage regulator on my 91 Dodge van. When the internal components of the alternator like the rotors, the brushes and the voltage regulator start to wear out, you will notice the following symptoms: 1) Dim headlights. Verifying charging voltage - confirmation that the alternator is working properly - from the comfort of the driver's seat with a cigarette lighter voltmeter. Fit a dc rectifier between the yellows and battery. In order to get maximum battery life proper charging voltage must be maintained. Automotive Alternator and Battery failures and how to fix the cause - Duration: basic voltage drop testing for automotive electrical testing - Duration: WAY TOO MUCH - Duration:. 1 it’s saying the alternator is bad. The red battery light goes off for three reasons, but it means there is an electrical problem. I personally know a friend with a 6lb lower and his went out at 59,000 miles. I have not ruled out the alternator, but its been like this for a year and still not a dead alternator. Once you've gone through and cleaned the ground connections, I'd check the charging circuit again with a voltmeter with the engine at idle - - turn on any accessories you can think of; all lights, A/C (fan on high), stereo, etc. I would take your Alt off and get it checked at a electrical shop that specializes in rebuilding electrical components as they normally have more and better testing equipment than the average mechanic. My car (2000 passat ATQ) was only putting out 12. The original voltage regulator unit has 2 wires going to it , one was an earth the other just terminatedi to a redundant Spade connector not connected to anything. the battery at too high a voltage, normal or too low. Alternator Output - Test Results Seem Weak I agree your output voltage maybe a little low, but I still cannot understand how you can continuously draw 75A from the battery yet only deliver 53A. If it is an internally regulated alternator, you can get an alternator from a 1980s B car. 5 or 14 it's good. The rotor spins and trips the circuit which starts the charging process. should be less than 100mv actually, assuming a good dmm and good. TEST 1: Testing Battery Voltage With The Engine Running. com - 18010/P1602/005634 - Power Supply B+ Terminal 30: Voltage too Low Username or Email Address. Undercharging destroys batteries too, but more subtly as the battery stratifies and will no longer maintain a charge. 9V at rest so anything lower than that coming from the alternator and it will still be draining the battery. That is just my guess. I think in the end most battery types will give good performance and longevity if they are properly maintained, and voltage and current are monitored with meters, and they are not drawn too low, and not drawn low too often. Flux created by regulating field opposes that created by compounding field and reduces the output voltage of alternator to normal value. Run a new #8AWG wire from the alternator output directly to the positive battery terminal, and a 8AWG wire from the alternator bracket bolt to the negative battery terminal, and see if that helps it. This goes to the PCM/ECM and is the field coil for the alternator. The lower intake (turkey pan) coolant crossover would need to be eliminated from the intake and plumbed externally to allow a deeper alternator design. It's a 2003 chevy tracker and the voltage regulator is built into the alternator so I wanted a work-around to avoid spending 160$ on a new alternator. Charging and voltage regulators: The green wire from the voltage regulator delivers a variable voltage (from 0-12V) to the alternator based on the voltage of the battery. I was married to her for 15 years. If you think you have a bad alternator, diagnose your problems with the alternator testing procedures below. Re: Does my alternator charge battery at low RPM? Contrary to what a lot of folks think, an alternator outputs a voltage/current any time it is turning (if field voltage is present). Ground good. Check the voltage between the alternator’s fat wire and its case. when the problem happens) measure the following: Voltage between the alternator power terminal and the battery + terminal should be well under 0. Just replaced the battery within the past 4 or 5 months. A regulator bypass test is an easy and quick way of determining if the alternator, regulator, or circuit is faulty. I hit a bump the other day and it was back to normal. Looks good. 8V coming from the alternator. If we use a diode at a higher current then the voltage drop will be higher and therefore the output voltage of the alternator will be increased by more. Symptoms of an Overcharging system are: Overheated battery (you may see a bulged out battery case) Low battery Electrolyte (water) Short battery service life (batteries should last 4 - 6 years) Light bulbs and fuses frequently fail (from too much amp flow). The regulator would adjust the alternator output voltage until the new voltage we fed into the regulator was correct. The alternator produces alternating current, the voltage regulator limits the voltage to 14. Flux created by regulating field opposes that created by compounding field and reduces the output voltage of alternator to normal value. A 12 V battery needs anywhere from 13. It's obvious the stock alternator can not produce enough power to keep the voltage in the 14v range. In the case of an alternator charging at 13. All it's doing is heating up the fuel and gobbleing up amps at idle. If it was a transient fault then recycling the 'alt' part of the battery master switch may bring the alternator back on line. This is usually based on a chevy alternator type and only requires a battery wire connected to the battery terminal. However, MM reads 13. Instead I elect to find the wire that runs between the fuse and the alternator and cut and solder a quick connector in. 6 is too high and it might have been the reason for the water level dropping so fast and the battery dieing. 8" even with a good alternator? if the battery is junk but the alternator works fine, could an alternator test of how many volts the car outputs while the car is on be low? would a bad battery and a good alternator still output 14. 3 volts is possible. Self-Exciting Alternator makes no need for Alternator Wiring Diagram The Self-Exciting alternator is an alternator that has a special voltage regulator that doesn't need an ignition wire to activate it. Undercharging destroys batteries too, but more subtly as the battery stratifies and will no longer maintain a charge. is too low Adjust* Electrical connections Inspect wiring are faulty connections High AC Output Incorrect voltage tap at No-Load on capacitor c. Basically, the voltage regulator senses the battery voltage on the S wire, and controls the current in the rotating field winding (Rotor) via F1 and F2. So the question becomes, why was your voltage too low?. Pin 1 = Alternator Feedback. I've seen the intermittent battery light when high loads are placed on the alternator like both AC units, radio, etc. You are correct, 18 volts is much too high, but an alternator can not cause over-charging unless it is assembled incorrectly with one of the brushes grounded through its mounting screw. HMMWV alternator on Deuce voltage too high? Well I checked my voltage on my dual voltage alternator (or is it generator?) and the high side is 29 volts and the low is 14. 16 - System Voltage too low (low output from alternator) Symptoms. (Voltage is like pressure that is behind elecricity as it travels thorugh a wire. the battery at too high a voltage, normal or too low. 6% of the primary voltage. If not I'll bet you are low and that causes problems too. 9 depending on the voltage regulator installed on your alternator. Therefore, the hose (wire) size is too small. Diode-based battery isolators typically loose about. With a heavy load on the alternator, as low as 13. If the alternator voltage is too low, than it cannot adequately charge the coach battery, so there is no reason to connect. And in the compressed air system, the pressure switch will turn on the compressor when system pressure gets low. Tested voltage across battery terminals 11. Note the trouble is that one brush is worn out. Here are the parts requires. Battery very low. , the voltage at the key switch will drop from 12. Cleaned the mass air flow sensor, all good. Usually, a battery warning light will go out once the car starts if the battery is being charged OK by the alternator, even if the battery still has slightly low voltage, but not 100% sure about this on the Genesis. Bad Alternator Sign #1: Flickering Headlights. For example, balanced two-phase power can be obtained from a three-phase network by using two specially constructed transformers, with taps at 50% and 86. The voltage regulator regulates volt/amps at its rating. volt gauge wont tell the story on a weak alternator. helly replied the topic: Alternator low charge at idle. Voltage rises during acceleration, but decreases once I take my foot off the accelerator. Battery very low. Look at the numbers at 5000 rpm. If the voltage does not rise (or the tester lamp or headlamps do not brighten) as engine speed increases, alternator output is too low or is not reaching the battery. It output about 14. So if we somehow fool the regulator into thinking the alternator output voltage is 0. This makes the alternator put out a higher voltage of around 14. Diagnosing Alternator Charging System Problems Over the years Harley Davidson has used many different alternator systems. However older (pre maint free battery) cars had a lower charging voltage with 13. Although this is from the DIC readout and not %100 accurate so I will multimeter it tomorrow. the truck doesnt die. When the battery voltage is high, the regulator feeds a low current into the field. Essentially the voltage regulator senses that the voltage is too low and uses the battery to supply current to the rotor. Other possibilities include a failing voltage regulator, or perhaps an alternator pulley that is too small. This voltage will be maintained when the battery is fully charged and the electrical load is low. 5 volts right away. We rechecked the battery and terminals, all clean and good, rechecked the alternator and voltage regulator, all checked fine. Have battery checked by certified auto center. The small alternator wire should read this same voltage, although it will almost certainly be a bit lower due to the resistance of the wire and the load it is feeding (the alternator rotor). The low voltage warning is coming on while the truck is idling. Under the extra load imposed by high power mobile applications, the alternator and/or the interconnect wiring may over heat. This time it should be at least 14. Once you've gone through and cleaned the ground connections, I'd check the charging circuit again with a voltmeter with the engine at idle - - turn on any accessories you can think of; all lights, A/C (fan on high), stereo, etc. In order to run 2ga I'd likely move the ammeter from the cockpit down by my battery switch downstairs and replace it with a green idiot D+ LED on my panel outside in the cockpit. While turning it to crank it stays the same at 9. Voltage: 480, 440, 400, 230 V Both an Electric propulsion motor and a clean energy generator supplying a stable AC electric network 3 Ph 50Hz or 60Hz from variable speed coming from output of the reducer or shaft line of the vessel. 5 - Too Low? - posted in Problems, Questions and Technical: After leaving my car a 1 or two days without a run, the car always starts but it is quite labored. Direct battery voltage (unregulated voltage) is used to excite the rotor field. Here is what happened:. In most cases, it also varies with the knowledge and skill level of the mechanic or technician. If voltage is good, turn on the headlights, interior lights, radio, heater, and any other electrical load. I did a lot of researching and found out that the alternator (Bosch 120a) should be putting out around 14. Check the voltage at the output of the alternator when the engine is idling, it should around 14 V in most cars, maybe a bit lower (13. Check the wiring diagram for your model year and locate the sense line to the logic module. 6 volts under minimal load which is too low for good battery recharge characteristics. The voltage regulator does just what it says: it regulates the voltage from the alternator. Think of them as similar to circuit protection devices, but instead of terminating connection when voltage spikes, they disconnect when voltage drops too low, preventing damage to the batteries and load. This is while driving not idle. 8V or greater, than the alternator is ok, and the problem is either the regulator or the wiring to/from the regulator. The voltage regulator can be easily replaced without removing the alternator most of the time, and usually is cheap so worth a try. However older (pre maint free battery) cars had a lower charging voltage with 13. 4 Check that the alternator is receiving the correct magnetization voltage. Make sure that when the master switch is on that you have battery voltage of at least 12 or 24 volts on the regulator battery terminal. 6 volts higher than this. the DC voltage function, on either side of a suspected connector. Engine performance wanes or sputters if voltage drops. If the generator puts out too many amps the system voltage will begin to rise. Re: More info about automotive alternator used as motor Since automotive alternators are well-known to be built to withstand a lot of heat, perhaps you could try running 24/36 volts through a 12-volt alt, or even 36 volts through a 24-volt alt. Changed to one size up from stock and it's charges fine at idle now. They were available in 80-100 amps, and are a direct plug-in part. engine and verify that no-load voltage is 13. This directly charges the battery, and will show you whether or not the alternator can produce under load, which the ac test doesn't. connected to the alternator are the positive, negative cables and a third smaller gauge wire connected to the alternator remote sense or (S) terminal. The AUX BAT light to the right should be flashing too. 11 volts is too low. To test a capacitor, a multi-meter that can test capacitance is required. TEST 1: Testing Battery Voltage With The Engine Running. It's obvious the stock alternator can not produce enough power to keep the voltage in the 14v range. Poor cranking when you want to start the engine (although you’ve replaced the car battery). 10-02-2012 #6. Make sure alternator belt is tight as slipping causes less charging, be sure all grounds and connections on the alternator and battery are clean, a new-ish voltage regulator still can have issues, and it all may be because your idle has fallen too low due to heat, ethanol in the fuel, or any changes that may have been made to ignition timing or carb tuning. This directly charges the battery, and will show you whether or not the alternator can produce under load, which the ac test doesn't. Still, using a few simple tests at home that show you how to test an alternator, how to inspect a battery, if necessary, and check a drive belt will help you pinpoint the cause of the problem. Put battery back in and took it for testing, their test said the voltage regulator was bad, so bought a new alternator, installed it, same thing, not charging. The average of the high/low output is the desired output voltage. Usually, a battery warning light will go out once the car starts if the battery is being charged OK by the alternator, even if the battery still has slightly low voltage, but not 100% sure about this on the Genesis. If your vehicle falls into this classification please wire your alternator per (Fig. This is while driving not idle. Since 1930 1-888-334-2632 www. This also necessitates a change to the voltage sensing relay connection – (with some dc-dc alternator chargers, that function is inbuilt). Load shedding basically is a function of the BCM or another module on the serial bus (Power Mode Master) watching battery voltage and doing something about it if it gets too low. Direct battery voltage (unregulated voltage) is used to excite the rotor field. Probing these same points with an oscilloscope will display the "mmm" or "picket fence" pattern of working. Only option is new guts in a 4g case. 2 is optimum). 8 being more common so perhaps that is what he was thinking. If the voltage is to high the battery will charge too quickly and may over charge. My stock alternator pulley has 5 grooves and the alternator I bought came with a 6 groove pulley. You used to be able to buy a little circuit box with switches on it that would apply 12 volts directly to the vehicles alternator field. probe, to assess the voltage regulator function and the field or rotor coil drive in an automotive dynamo or alternator system. The Conventional Alternator. While probably rare alternators can put out good voltage and current at low RPMs but fall on their face when spun hard. If your battery is charged to 12VDC and the bottom of that ripple goes below 12VDC, it will act like an alternator (AC) rather than a generator, at least around the limit. This modest increase in system voltage should not be a problem for any of a Sprite's electrical equipment, new or original. A charging voltage of 12. 1 it’s saying the alternator is bad. With very low inertia loads, the inertia of the engine and alternator may be sufficient to supply the power to start the load, but there will still be a significant frequency droop. After I smoked both of those raptor fans due to low voltage within one week, I ditched them for FAL fans that use significantly less current. The voltage will not go back up unless i turn everything off, it just keeps dropping. The voltage may dip too low and you will notice the headlights can’t illuminate the road well. When the top contact points are closed, maximum system voltage is applied to the alternator’s field (charging). Learn what does P1682 Dodge Charging System Voltage Too Low means, location and how to repair? The Powertrain Control Module (PCM) tries to maintain a system voltage between 12. Still too low. CHARGING SYSTEM TEST Charging system tests should be performed when problems point to low alternator voltage and current. In checking the trouble code and, a code P0562 system voltage too low was indicated. If you get a low voltage reading, like around 12V, then the alternator is the issue. 3 vdc to 15. Ideally, the voltage drop across any connection should be zero or less than 0. This happens mostly at low idle, such as when stopped and idling, but it also occurs randomly at higher idle speeds. Alternators are designed to have a power curve that increases with RPM, low RPM low output high RPM high output. If one single alternator is used to supply power to the high voltage transformer, the method of variation of alternator field current can be performed. Signs that you could do with a new alternator voltage regulator include: Your battery is not charging to full capacity. Alternator voltage regulator failure with built in high/low alarms. After a short trip today the idle voltage was > 14. Now realize, I am in Texas - its 100 degrees and the A/C is blowing HARD so I know that takes power. Bought new battery. Batteries can do. Run at least an 8 AWG wire from the alternator to the battery. It is not uncommon for a 160 amp alternator to have a continuous duty cycle of less than 90 amps. I thought at first that their test could be wrong too considering I had just installed the new* alternator, but doesn't it seem like the voltage is dropping too much with the loads on for everything to be. The output voltage of an alternator is best controlled by regulating the voltage output of the dc exciter, which supplies current to the alternator rotor field. I replaced the voltage regulator yesterday with a new one and that didn't turn the light off so today I just put in another alternator with the new voltage regulator. I thought well it has to be the alternator. This voltage will be maintained when the battery is fully charged and the electrical load is low. High voltage is like high pressure. It is possible to replace an internal regulator but local auto parts stores only sell whole alternators. Some alternator/regulator setups seem to sit a little below this, but that's fine. If your alternator has a lot of power to charge, don't give it any resistance by installing too small of a charging wire. I did a lot of researching and found out that the alternator (Bosch 120a) should be putting out around 14. Correct charge voltage from the alternator, then its time to start on the smart charge system, and you will need a scope. Troubleshooting Amperage Output. But, if during operation, the alternator output is greater than battery voltage, but less than system operating voltage, the alternator has a low output. 4 volts--Not usually a problem for AGM. At the left the alternator is yielding 15. Note, the alternator does not work very efficiently at a low rpm, the alternator needs to get above 3000 rpm to get a good reading. I paid 160 Euro for a new one from Germany (IL Motorsport). Run at least an 8 AWG wire from the alternator to the battery. If not I'll bet you are low and that causes problems too. Tip : If the voltage is low, you can lightly wiggle the electrical connections on the back of the alternator to see if the voltage changes. It is fine for that, but far too low for charging auxiliary RV batteries. 8 being more common so perhaps that is what he was thinking. in the rec. After driving for a while, say 45 minutes, the voltage doesn't drop so I'm assuming the alternator is charging. 5 ( too high ) I took the car back to the mechanic and They did a rebuild on. The alternator uses mechanical energy to work, and this is provided by the motor using a belt. Modern cars have a large amount of electrical equipment which can go wrong and so need checking. Can be built into the generator or purchased as a hand held unit. Over-charging is caused by the voltage regulator driving the alternator too hard. It's very frustrating as I've been down that road with low voltage at WOT but everyone keeps insisting the alternator is good. 15v; a little more than the cells own voltage of 2. If you detect even a small amount of AC voltage, replace the alternator. I am pretty sure the voltage regulator inside the alternator is temperature compensated. 2v or so at idle. If the voltage is still too low, check to be sure all the connectors on your alternator are tight and that the alternator belt is not slipping and is spinning on the pulley correctly. I thought well it has to be the alternator. It worked for a while then failed. A typical passenger car has a 100Amp alternator. Voltage would be low (8-10 at low rpm) initially but always come back to 12 or higher after a small time. Instead I elect to find the wire that runs between the fuse and the alternator and cut and solder a quick connector in. When I stop at traffic lights, my voltage begins to dip. First the system. Cleaned the mass air flow sensor, all good. First diagnose P1633 code. This voltage is not too important because the battery will slowly and steadily settle to a new voltage that indicates the true state of battery charge, but the voltage measured right at engine shutoff is a very clear indicator if the alternator or charging system is charging. Started engine voltage meter registered 11. 5 volts is a little low, should be up in the 13 to 14 volt range. The exact charging voltage will vary according to the battery’s state of charge, the load on the vehicle’s electrical system, and temperature. I have a 2008 Chevy Silverado. The AUX BAT light to the right should be flashing too. The Jeep was running on the battery only, as the alternator was not working. Controller failure, check the PCM. The14 volt in question is too low of a system voltage for the modern car. You are correct, 18 volts is much too high, but an alternator can not cause over-charging unless it is assembled incorrectly with one of the brushes grounded through its mounting screw. (Voltage is like pressure that is behind elecricity as it travels thorugh a wire. Actually a smaller alternator would make a better welder, this thing has to be turned down too far for normal welding and the open circuit voltage gets to be too low to start the arc. • 48-volt Alternator Output Voltage Is Over 68 Volts Poor connections on alternator or alternator harness. Some of those voltages were measured at heat on full blast too. Any problems with your alternator or voltage regulator? Is it the voltage regulator or alternator that is causing the issue? Need to know about Honda voltage regulator? Get answers to all your questions about Honda voltage regulator problems by asking Honda Mechanic Experts on JustAnswer. They are usually designated by amperage out put such as a 22- amp or a 32-amp system. Load shedding basically is a function of the BCM or another module on the serial bus (Power Mode Master) watching battery voltage and doing something about it if it gets too low. The Alternator is a Ford. The regulator would adjust the alternator output voltage until the new voltage we fed into the regulator was correct. Still, using a few simple tests at home that show you how to test an alternator, how to inspect a battery, if necessary, and check a drive belt will help you pinpoint the cause of the problem. 5 - 14 volts or so with no electrical equipment on and the engine idling. To test a capacitor, a multi-meter that can test capacitance is required. Still, it's perfectly normal for others to see the alternator not charge at all intermittently. 4 and with a good load on (no not that!) [high beams, rear > defrost, heater fan, radio loud] it was 14. The warning light should illuminate when the key is turned to the ON position as a bulb check. The battery is needed to start the vehicle, which, in turn spins the alternator at sufficient speed to keep the battery charged. A 90-amp alternator will output approximately 88 amps. It is possible to replace an internal regulator but local auto parts stores only sell whole alternators. 3 i just put a new alternator and battery in the truck Any time i put any kind of a load on the alternator the voltage meter drops down to as low as 9-10ish. The output voltage of an alternator is best controlled by regulating the voltage output of the dc exciter, which supplies current to the alternator rotor field. Cleaned the mass air flow sensor, all good. If the alternator becomes a load at low enough speed (or you hae enough accessories on to pull down the battery), then you could get voltages that are below the battery's 'nominal' voltage. The 4g alternator is the thinnest out there. In some instances, systems other than the alternator can cause low voltage codes. 5 Regulator fault; check with another alternator. Check the current with an i410 or i1010 current clamp. 2 volts) to effectively charge a 12 volt car battery. I checked the voltage on the engine and it showed 12. 6) Now, Maintain the 1500 RPM and Turn off the Headlights. Therefore, the hose (wire) size is too small. The battery is a little pickier about its charging voltage. When a regulator fails, the limits on how much power an alternator can produce disappear. Also, the RPMs at idle when this occur stay very steady at 650. If everything else checks out, then the regulator or the alternator itself may be bad. Excessive overheating of alternator frame (more than 40° C above the ambient temperature) - Air flow (inlet-outlet) partially clogged or hot air is being recycled from the alternator or engine - Alternator operating at too high a voltage (>105% of Un on load) - Alternator overloaded. Alternator problems manifest themselves in various ways, depending upon the particular failure. 5-volts) as it sits and idles, rev it to about 1100 to 1200 RPM. The system voltage information is taken from the PCM 's ignition feed circuits. Voltage regulators also fail by generating too much power. Small generators like this draw their excitation power from the output of the generator, have no AVR, nor any Boost capability; i. 2, the battery was just being charged. If it does the generator is o. Mine is 13. My first alternator went out at about 30,000 miles. 2 at idle all equipt on i guess i shall see how long this new $89 alternator will last its not a delco but i still have my old one to have rebuilt if needed the prices i get to rebuild mine is $125. It can be caused by the charging system, damaged wiring, or even a bad TCM. 5 volts eventually. The next morning, I received a call to come back onboard, the voltage had dropped from 380V down to 320V, the crew onboard had raised the voltage level back to 380 on the AVR, and I left again, and now a few weeks ago, I came back onboard, and the people explained, the voltage is swinging between 250V and 450V, or around there, not really sure, but he told me they kept raising the voltage setpoint back to 380V each time, this problem happened, which could happen with low to mid-level load. It should have the same voltage as at the alternator. Usually, a battery warning light will go out once the car starts if the battery is being charged OK by the alternator, even if the battery still has slightly low voltage, but not 100% sure about this on the Genesis. Cold batteries can tolerate / need a higher charging voltage, an alternators voltage rise on lower temps is by design. Lights will dim, electric cooling fans will slow, and the engine could even stumble. After the AC/DC conversion, the resulting voltage is ready to use in the battery. The unit installs with only three wires (two to the battery, one to the ignition switch) and mounts using the adhesive pad and tie provided. After I run the blower for 15 sec. These tests will quickly determine the operating condition of the charging system. Low power single phase alternators often have simple excitation systems that use the output of the alternator to provide the field current, and are incapable of supplying high inrush current loads. Bought new battery. 8 but as soon as I turn the key to the on position it drops down to around 9.