Series 2 RX8 battery question on ignition system
02-24-2017, 01:00 PM
#1
Registered
Thread Starter
Series 2 RX8 battery question on ignition system
Ok the 5 year old OEM Mazda battery that came with my 2010 GT RX8 finally croaked its last crank yesterday morning and wouldnt even turn on the Starter Motor when was going out for lunch but all electrical works fine LOL...
I live in California so I went ahead and got a Optima Yellow Top and installed it while I was at work...And my RX8 is alive again.
But I noticed something strange in a good way.
1. RX8 starts instantly with one click
2. Idle is more smoother
I was under the impression that RX-8's like my previous RX-7 switches everything over to the Alternator once everything is running...which should in turn wont affect anything the way my car runs with the old battery compared with the new one.
Am I wrong?
I live in California so I went ahead and got a Optima Yellow Top and installed it while I was at work...And my RX8 is alive again.
But I noticed something strange in a good way.
1. RX8 starts instantly with one click
2. Idle is more smoother
I was under the impression that RX-8's like my previous RX-7 switches everything over to the Alternator once everything is running...which should in turn wont affect anything the way my car runs with the old battery compared with the new one.
Am I wrong?
02-24-2017, 01:39 PM
#3
The "poor" battery will draw current as it tries to charge itself...so that effectively lowers the alternator output available to run the car. It will 9ften lower the voltage a bit as well over a good battery.
From my observations with the high load from the RX8 steering and other systems this can be a problem if you have a weak battery
From my observations with the high load from the RX8 steering and other systems this can be a problem if you have a weak battery
02-24-2017, 02:02 PM
#4
///// Upscale Zoom-Zoom
The modern electrical system regulates voltage using the battery as part of the regulation system. The battery must be within its normal life operating range. Once the battery has issues with electrolyte, plate surface area charge capacity, salting out in the lower level of the battery, and the like, the battery portion of the regulation system causes issues [you describe]. BMW over-engineers cars by monitoring a series of parameters and will limp or not allow the car to operate when the battery is getting long in the tooth. Mazda and the RX-8 simply has issues that you described creating a no start condition.
I always use AGM or standard batteries in my cars and have had one and only one issue with the Optima. I gave up and went back to what works in cars.
I always use AGM or standard batteries in my cars and have had one and only one issue with the Optima. I gave up and went back to what works in cars.
02-24-2017, 02:05 PM
#5
///// Upscale Zoom-Zoom
Both my cars (2013 aged battery) and the RX-8's (2014 aged battery) will be replaced this Spring as preventative maintenance.
02-24-2017, 02:14 PM
#6
///// Upscale Zoom-Zoom
The battery is an electrical storage reservoir, similar in function to the air tank for the compressed air system. (Actually, the battery does not store electricity, it would be more correct to say; “the battery stores ingredients that can produce electricity.”) Both the battery and the air tank can store a source of energy in reserve, keeping energy available for the times we need it.
The alternator produces electrical power, which can operate devices that perform work for us. And the compressor produces the compressed air, which can be used as a source of power to operate tools or machinery.
The voltage regulator limits the maximum voltage in the electrical system. In the compressed air system the pressure regulator limits the maximum pressure. The voltage regulator will also cause the alternator to produce more output, when voltage (pressure) at the electrical system is low. And in the compressed air system, the pressure switch will turn on the compressor when system pressure gets low.
Lights, ignition, and accessories use power from the electrical system. Every time we switch an accessory ON, more power is drawn from the system. Voltage (electrical pressure) drops as power is drawn from the system, and then the voltage regulator causes the alternator to make more current. And in the compressed air system an impact wrench, blowgun, paint gun, or the fitting for filling a tire, can all use power (compressed air) from the system. When we use compressed air from the system, PSI (air pressure) drops, and the regulator turns the compressor ON. In the electrical system, the voltage regulator “turns the alternator ON,” or “turns OFF the alternator” as needed to maintain voltage at the proper level. And in the air compressor system the pressure regulator stops and starts the compressor as needed to maintain the proper level of pressure.
The useful electrical system will require an alternator that can produce an average of more output than we use, and the regulator will limit system voltage to the safe level we need. Like most machinery, the alternator cannot stand to work at maximum output for extended periods of time. Short bursts at maximum output are okay, but normal operation will require alternator operation at only a part of full output potential, most of the time. Alternators make heat as a by-product of making electrical power, and the more power they supply the more heat they make. Some models of alternators can stand to put out a much higher percentage of their gross output rating than others, during extended periods of operation.
Air compressors have “duty cycle” ratings. The compressor also produces heat as a by-product, and if it was called upon to run continuously while maintaining high pressure, the compressor will burn out. Some models of air compressors will have a greater duty cycle than others. Expect that a hobby shop model will not be intended to run for the long time periods that a professional workshop compressor is built for.
When the electrical system needs more power than the alternator can produce, for a short time, then the battery is already connected to the system and the battery will contribute the needed power. Entering into this picture is that the alternator must spin at sufficient RPM to produce power. And there is an alternator power output/RPM curve, where available output increases with RPM. There is also a minimum and maximum for practical alternator RPM operating range. Alternator RPM is somewhat adjustable by changing the ratio of the drive pulley at the crankshaft and alternator pulley diameters. But since the engine will run slowly at times, and rev very high at other times, there is no “perfect” pulley drive ratio for all applications. The pulley drive ratio is a compromise; and what’s acceptable at maximum RPM is the deciding point. (An alternator can be damaged with excessive RPM.) A pulley ratio that is good with 6,500 to 8,000 engine RPM on a circle track is far from ideal with the in-line six engine in “Grandma’s grocery getter.”
At low RPM, expect that early models of alternators often produced much less available output than more modern designs. And with many models of old alternators, electrical output at engine idle speed was not sufficient to support electrical demands. But when sitting at a stoplight, the battery could assist the alternator with support of the electrical system. And then when the light turned green we drove away with the engine spinning the alternator fast once again. The alternator soon replaced power used from the battery while sitting at the stop light, no harm done. System voltage will be low, when the alternator is not keeping up. (Voltage will be above 14 when the alternator is working, and about twelve and falling when supported by the battery.)
Drivers of old cars were accustomed to the lights dimming at idle, or the turn signals blinking slower–it was simply the result of low voltage when the alternator did not keep up. The older cars could get by with less than perfect performance. And with fewer electrical items to support, then the voltage did not drop off so quickly. The old cars also did not have electronics that would cease to operate at low voltage. With the duration of city traffic jams in modern times, the many accessories on a modern car, and electronics that are sensitive to low voltage, of course alternator output at engine idle speed had to get better. The newer designs of alternators can produce a lot more current at low RPM, even when the gross output rating is nearly the same with the old model.
In parallel to the electrical system, with the air compressor at marginal capacity, there will be times when system pressure gets low. As when friends come over to help with a project on the weekend, all armed with air tools to operate from the small compressor in the garage. (And as with electrical systems, this didn’t likely happen back in the 1960’s!) The small compressor cannot support an air ratchet, an impact wrench, a blowgun, and a grinder with a cut-off wheel all at once. During those times the reservoir (tank) would have to supply power (compressed air). When average use is more than the amount produced by the compressor, then system pressure falls low.
The electrical system behaves about the same. If the average output from the alternator does not keep up with electrical system power use, then the battery falls to discharged condition, and system voltage falls below acceptable level.
The table below shows about what to expect with differences in alternators that are only one generation apart. (‘60s type externally regulated compared to ‘70s type internally regulated. About the same test results have been observed on many occasions, when doing alternator up-grades. The same “stock” pulley drive ratio was with both types of alternators. (1969–1972, small block 350 engine, stock pulleys)
One more aspect of the comparison between the electrical system and the compressed air system, and that is “PRESSURE DROP” with long “lines” used for delivery. In the electrical system long lengths of wire will have resistance, amounting to a restriction of electrical power flow. And the farther down the wire we check voltage, the lower the voltage (electrical pressure) will be. Also, with increased current flow, the voltage drop (pressure drop) will increase. In example, if we attempt to operate a really powerful electrical device such as a starter, through a long, small diameter wire, then starter performance will be poor. The starter motor will attempt to draw a large amount of current through the long, small gauge wire, and voltage will be weak at the starter end of the wire. In another example, if wires from a headlight switch all the way out to the front of the car are thin in gauge size diameter, then voltage to the lights will be low resulting with dim lights.
The same can happen with compressed air systems. In younger years, there were occasions where working with air tools at low pressure was a constant irritation. Imagine an old building, with a large compressor at the far end of a long building. Back in the 1940’s compressed air was mainly used to air-up tires, but not to provide service for busy mechanics wielding air ratchets and impact wrenches. The building was equipped with very old, small diameter steel tubing for the compressed air service. In that facility, the mechanic farthest away from the compressor did not receive air at full pressure. If an air ratchet or tool requiring a large volume of air was used, then the tool was down on power. Larger diameter tubing would have really improved performance of the air tools. Especially so when other mechanics closer to the compressor were using air before it gets to the end of the line.
The situation with the long, small diameter tubing, for compressed air, had the same effect as with a long small wire used to operate many powerful accessories. The accessory farthest down the wire will receive power at low voltage (pressure) level. Larger wire diameter will improve performance by delivering power at higher voltage (pressure.) Or… Use a system design providing a shorter length wire, which also will improve performance.
And now for those who enjoy the technical aspects of how things work, here is a more detailed explanation of system operation with the
ALTERNATOR, VOLTAGE REGULATOR and BATTERY.
The alternator will generate power to operate the electrical system plus keep the battery charged. The purpose of the voltage regulator is to regulate the amount of power output from the alternator. (Of course! What else do regulators do? Ha!) The voltage regulator will allow the alternator to make enough power to maintain proper voltage level, but not allow system voltage to rise to a harmful level.
With regulators for the alternator system, voltage limiting is the means of controlling output. (The older “generator” systems had a voltage limiter and also a current limiter, plus a “cut-out relay” that disconnected the system when the engine stopped.) If the alternator was allowed to constantly produce all the power it could, system voltage would rise to a damaging level, the battery would overcharge, components would be damaged, and the alternator would soon overheat and burn out.
With a 100amp alternator installed, we do not drive around with the alternator constantly producing 100amps. When driving a simple car, in example a ’66 Chevelle, with no accessories switched on, stock ignition, and the battery topped off with a charge, the alternator produces only about 3amps to 5amps of current! (No matter how powerful the alternator, output is limited according to system demands.)
And, in case you are wondering, the amount of horsepower used to spin the alternator changes with output. When the alternators produce only a small amount of current, the horsepower drag is very small (less than 1/3 amp). Large amount of output causes more horsepower drag (about 3 or 4 horsepower to produce 120amps output).
The alternator produces electrical power, which can operate devices that perform work for us. And the compressor produces the compressed air, which can be used as a source of power to operate tools or machinery.
The voltage regulator limits the maximum voltage in the electrical system. In the compressed air system the pressure regulator limits the maximum pressure. The voltage regulator will also cause the alternator to produce more output, when voltage (pressure) at the electrical system is low. And in the compressed air system, the pressure switch will turn on the compressor when system pressure gets low.
Lights, ignition, and accessories use power from the electrical system. Every time we switch an accessory ON, more power is drawn from the system. Voltage (electrical pressure) drops as power is drawn from the system, and then the voltage regulator causes the alternator to make more current. And in the compressed air system an impact wrench, blowgun, paint gun, or the fitting for filling a tire, can all use power (compressed air) from the system. When we use compressed air from the system, PSI (air pressure) drops, and the regulator turns the compressor ON. In the electrical system, the voltage regulator “turns the alternator ON,” or “turns OFF the alternator” as needed to maintain voltage at the proper level. And in the air compressor system the pressure regulator stops and starts the compressor as needed to maintain the proper level of pressure.
The useful electrical system will require an alternator that can produce an average of more output than we use, and the regulator will limit system voltage to the safe level we need. Like most machinery, the alternator cannot stand to work at maximum output for extended periods of time. Short bursts at maximum output are okay, but normal operation will require alternator operation at only a part of full output potential, most of the time. Alternators make heat as a by-product of making electrical power, and the more power they supply the more heat they make. Some models of alternators can stand to put out a much higher percentage of their gross output rating than others, during extended periods of operation.
Air compressors have “duty cycle” ratings. The compressor also produces heat as a by-product, and if it was called upon to run continuously while maintaining high pressure, the compressor will burn out. Some models of air compressors will have a greater duty cycle than others. Expect that a hobby shop model will not be intended to run for the long time periods that a professional workshop compressor is built for.
When the electrical system needs more power than the alternator can produce, for a short time, then the battery is already connected to the system and the battery will contribute the needed power. Entering into this picture is that the alternator must spin at sufficient RPM to produce power. And there is an alternator power output/RPM curve, where available output increases with RPM. There is also a minimum and maximum for practical alternator RPM operating range. Alternator RPM is somewhat adjustable by changing the ratio of the drive pulley at the crankshaft and alternator pulley diameters. But since the engine will run slowly at times, and rev very high at other times, there is no “perfect” pulley drive ratio for all applications. The pulley drive ratio is a compromise; and what’s acceptable at maximum RPM is the deciding point. (An alternator can be damaged with excessive RPM.) A pulley ratio that is good with 6,500 to 8,000 engine RPM on a circle track is far from ideal with the in-line six engine in “Grandma’s grocery getter.”
At low RPM, expect that early models of alternators often produced much less available output than more modern designs. And with many models of old alternators, electrical output at engine idle speed was not sufficient to support electrical demands. But when sitting at a stoplight, the battery could assist the alternator with support of the electrical system. And then when the light turned green we drove away with the engine spinning the alternator fast once again. The alternator soon replaced power used from the battery while sitting at the stop light, no harm done. System voltage will be low, when the alternator is not keeping up. (Voltage will be above 14 when the alternator is working, and about twelve and falling when supported by the battery.)
Drivers of old cars were accustomed to the lights dimming at idle, or the turn signals blinking slower–it was simply the result of low voltage when the alternator did not keep up. The older cars could get by with less than perfect performance. And with fewer electrical items to support, then the voltage did not drop off so quickly. The old cars also did not have electronics that would cease to operate at low voltage. With the duration of city traffic jams in modern times, the many accessories on a modern car, and electronics that are sensitive to low voltage, of course alternator output at engine idle speed had to get better. The newer designs of alternators can produce a lot more current at low RPM, even when the gross output rating is nearly the same with the old model.
In parallel to the electrical system, with the air compressor at marginal capacity, there will be times when system pressure gets low. As when friends come over to help with a project on the weekend, all armed with air tools to operate from the small compressor in the garage. (And as with electrical systems, this didn’t likely happen back in the 1960’s!) The small compressor cannot support an air ratchet, an impact wrench, a blowgun, and a grinder with a cut-off wheel all at once. During those times the reservoir (tank) would have to supply power (compressed air). When average use is more than the amount produced by the compressor, then system pressure falls low.
The electrical system behaves about the same. If the average output from the alternator does not keep up with electrical system power use, then the battery falls to discharged condition, and system voltage falls below acceptable level.
The table below shows about what to expect with differences in alternators that are only one generation apart. (‘60s type externally regulated compared to ‘70s type internally regulated. About the same test results have been observed on many occasions, when doing alternator up-grades. The same “stock” pulley drive ratio was with both types of alternators. (1969–1972, small block 350 engine, stock pulleys)
One more aspect of the comparison between the electrical system and the compressed air system, and that is “PRESSURE DROP” with long “lines” used for delivery. In the electrical system long lengths of wire will have resistance, amounting to a restriction of electrical power flow. And the farther down the wire we check voltage, the lower the voltage (electrical pressure) will be. Also, with increased current flow, the voltage drop (pressure drop) will increase. In example, if we attempt to operate a really powerful electrical device such as a starter, through a long, small diameter wire, then starter performance will be poor. The starter motor will attempt to draw a large amount of current through the long, small gauge wire, and voltage will be weak at the starter end of the wire. In another example, if wires from a headlight switch all the way out to the front of the car are thin in gauge size diameter, then voltage to the lights will be low resulting with dim lights.
The same can happen with compressed air systems. In younger years, there were occasions where working with air tools at low pressure was a constant irritation. Imagine an old building, with a large compressor at the far end of a long building. Back in the 1940’s compressed air was mainly used to air-up tires, but not to provide service for busy mechanics wielding air ratchets and impact wrenches. The building was equipped with very old, small diameter steel tubing for the compressed air service. In that facility, the mechanic farthest away from the compressor did not receive air at full pressure. If an air ratchet or tool requiring a large volume of air was used, then the tool was down on power. Larger diameter tubing would have really improved performance of the air tools. Especially so when other mechanics closer to the compressor were using air before it gets to the end of the line.
The situation with the long, small diameter tubing, for compressed air, had the same effect as with a long small wire used to operate many powerful accessories. The accessory farthest down the wire will receive power at low voltage (pressure) level. Larger wire diameter will improve performance by delivering power at higher voltage (pressure.) Or… Use a system design providing a shorter length wire, which also will improve performance.
And now for those who enjoy the technical aspects of how things work, here is a more detailed explanation of system operation with the
ALTERNATOR, VOLTAGE REGULATOR and BATTERY.
The alternator will generate power to operate the electrical system plus keep the battery charged. The purpose of the voltage regulator is to regulate the amount of power output from the alternator. (Of course! What else do regulators do? Ha!) The voltage regulator will allow the alternator to make enough power to maintain proper voltage level, but not allow system voltage to rise to a harmful level.
With regulators for the alternator system, voltage limiting is the means of controlling output. (The older “generator” systems had a voltage limiter and also a current limiter, plus a “cut-out relay” that disconnected the system when the engine stopped.) If the alternator was allowed to constantly produce all the power it could, system voltage would rise to a damaging level, the battery would overcharge, components would be damaged, and the alternator would soon overheat and burn out.
With a 100amp alternator installed, we do not drive around with the alternator constantly producing 100amps. When driving a simple car, in example a ’66 Chevelle, with no accessories switched on, stock ignition, and the battery topped off with a charge, the alternator produces only about 3amps to 5amps of current! (No matter how powerful the alternator, output is limited according to system demands.)
And, in case you are wondering, the amount of horsepower used to spin the alternator changes with output. When the alternators produce only a small amount of current, the horsepower drag is very small (less than 1/3 amp). Large amount of output causes more horsepower drag (about 3 or 4 horsepower to produce 120amps output).
02-24-2017, 02:15 PM
#7
SARX Legend
iTrader: (46)
Yeah most store carry their own brand of AGM's with 3-5 year warranties anyway. Optima is only one year. I have a H8 AGM in my BMW from Advance and it has worked great so far. I just replaced the Odyssey in my RX-8 right after the 3 year warranty ran out. But three years in south Texas is pretty average and the car sits a lot so that doesn't help either.
02-24-2017, 02:19 PM
#8
///// Upscale Zoom-Zoom
Yeah most store carry their own brand of AGM's with 3-5 year warranties anyway. Optima is only one year. I have a H8 AGM in my BMW from Advance and it has worked great so far. I just replaced the Odyssey in my RX-8 right after the 3 year warranty ran out. But three years in south Texas is pretty average and the car sits a lot so that doesn't help either.
