How much current does the bike alternator produce?


Bike alternators are designed to produce current for charging batteries. The power they can generate is limited by the battery’s capacity and the engine’s rpm. For example, a 500-watt bike alternator might charge a 12-volt car battery at about 10 amps, which would take 8 hours. However, if you have a 24-volt car battery, it could take up to 16 hours for that same 500-watt bike alternator to fully charge it because it has less voltage available to use as a charging current.

The alternator is rated at 400 Watts (over its full temp/speed range). This means it can provide about 28 Amps. Is the likelihood of you ever running the amp capacity on this device? Well, that’s hard to say!

This is why it’s not feasible to charge car batteries with a bike alternator. It would take too long, and you’d need at least two or three times the wattage available from your motorcycle engine. 

You might be able to buy a bigger alternator (like 1000 watts) that can produce more current if you have an even larger battery capacity than 24 volts,Opens in a new tab. but this will cost quite a bit of money. 

For example, Buell motorcycles used 500-watt bike generators as part of their charging system made by Harley Davidson. These sportbikes had very large 12-volt batteries for an extra range between gas fill-ups up to twice as big in some cases compared to other regular-size motorcycle batteries. But then again, these bikes were made for very long trips along the highway.

The bottom line is that to charge a car battery from your bike; you’ll need an alternator designed specifically for charging automotive batteries. 

The best way is by using one small motorcycle batteryOpens in a new tab. and then putting it inside another metal box (like a toolbox) that has enough room on top to hold the extra wires coming out of your car’s charging system. 

You could even put some kind of cordless drill or other similar electrical devices inside as well if you want. Because most 12 volt DC devices will work with all kinds of different voltage levels between 11 volts and 14 volts at low current loads like what they might use in cars, especially since there are now so many different types of 12-volt power outlets inside vehicles.

The last thing you’ll need is a way to mount this whole contraption securely on your bike. There are ways of doing this, but I like using the old school “bicycle generator” type brackets that clamp around the down tube and seat post. You can buy these at any hardware store or bicycle shop, and they’re not too expensive. Just make sure it will fit your particular motorcycle model before buying it.

Motorcycle Alternators

The first and less common type of motorcycle alternatorOpens in a new tab. is the automotive-type, externally mounted self-contained “one-piece” unit. It contains all needed to create current output in just one package.

The alternator is a device that generates electricity and distributes it to the bike’s electrical system. This type of mounting makes them external, so they can generate more heat than other internal or exterior-mounted alternatives such as those found on large touring bikes where capacity is required in greater amounts due to their size.

A third option would be an onboard generator which does not require any outside help by way of power production but instead relies solely upon its engine performance.

The alternator is a device that converts the electrical energy from your engine into AC power for use in everyday life. It does this by using magnets and an energized field coil, which form part of its operation depending on its design. 

Either with small, powerful insets within them or less commonly through one big magnet near where you’ll find brushes attached to conducting wires leading away from other parts inside.

The first type we’ll look at are those equipped With “exciting” coils: These come in two varieties-BrushLess versions (which operate Using just battery voltage) And Brush furnaces trained electric motors helping fuel efficiency.

External rotors are used to cover a wide range of applications, from small motors in appliances up through industrial compressor pulleys and drive shafts. Internal type magnets have been found on just about every kind known. They’re even present within some commercial air conditioning units.

How much current is produced by the alternator?

The output of an alternator is determined by its rating. The range for 40 Amp will vary depending on how much power you need. Still, commercialized units are usually 12 V to make it easier for customers with higher voltage requirements. For example, 48V or 60 Hz systems require separate powered equipment from time to each other because these types don’t exist without sacrificing something else entirely.

It is important to know the difference between an alternator’s output and demand. The higher the speed at which it rotates, the more power will be given out; however, this depends on how many times your vehicle’s electrical system requests energy from them during a single charge cycle- meaning there can never really BE too much.

This question comes up every year as new riders get their first bikes. They wonder if that little alternator can even produce enough current to handle all the electrical needs of a bike, and the answer is yes.

It’s common for people with bigger motorcycles (or at least those whose owners are careful about not draining the battery too much) to ride around on one single 12-volt motorcycle battery just fine without ever thinking twice about charging issues. 

Because they don’t run out of power very fast, no matter how hard they hammer away down twisty roads or race off into long straightaways unless maybe there’s extra weight in sidecars like larger families riding together sometimes do. But then again, most of these folks who have lots of fun with their three-wheeled friends usually have more than one bike battery on hand as a spare, and they know how to use them.

That said, if you’re the kind of person who likes to go camping with your motorcycle, or uses it for other recreational purposes away from electrical outlets, then you might want to consider getting an extra battery or two. 

You can buy them pretty cheaply at any automotive parts store, and they’ll come in real handy when you need that added peace of mind while riding off into the sunset, knowing you won’t get stuck out in the middle of nowhere without a way to power your cell phone or GPS unit. 

Just make sure your charging system is up to the task of handling all those amps (or watts) when you’re trying to recharge multiple batteries simultaneously.

The amount of power your battery can take varies depending on the alternator’s rotation speed. If you want to charge quickly, make sure that it is spinning at least 2k RPM or more but no less than 1kHz

“This means,” says National Resources Defense Council lawyer David Zucchino in a report by LA Times, “you need an engine with higher torque output like those found in cars designed before 2000.”

Most stock charging systems on bikes today are designed for either 12 or 18 volts, so if you have a 24-volt battery, then you’ll need an alternator that can produce more current than what’s commonly available. 

This isn’t too difficult to find these days, but it will cost more than a standard unit. You can get away with using a smaller bike generator on a bigger motorcycle as long as the battery is rated for more amps than the alternator can put out. But this might not be the best idea because it will wear down your battery faster in the long run. 

So if you want to use a different voltage battery (or even upgrade to one of those new lithium-ion models), then you’ll need to make sure your charging system can handle it.

How many volts is a motorcycle alternator?

The voltage between the terminals of a stator coil at 3,000 rpm can vary anywhere from 20 volts on up to 50VRMS. This is important information for any motorcyclist who wants their bike’s performance-optimized!

Motorcycle alternators are usually either 12, 14, or 18 volts. The first thing you’ll need to do before upgrading is determine which type of charging system your bike has; otherwise, you won’t be able to find one with the right voltage for it.

This might sound like a bit of a hassle, but it’s pretty easy if you have some basic knowledge about how electric motors work (or even just know what kind of motorcycle yours is). If not, then check out our article on How To Check Your Motorcycle Charging System so that we can tell from there what model number and specifications we’re looking for. 

Then all you have to do is search online until the results show up in whatever format they use nowadays on these e-commerce websites, or if you prefer to use old-fashioned books and magazines, just visit your local library.

When you turn on your motorcycle’s engine, the magnetized rotor inside starts turning, changing its magnetic field, which attracts electricity from coils within the stator. It works like an electric motor but opposite way.

How many amps does a motorcycle stator put out?

This is a stator test to see if your AC system can produce proper voltage at 1000 RPM. For example, 18 volts per 1000-RPM should be produced when the motor has 32 amps of power running through it (think about how fast this would happen). At 2000 rpm, there needs to account for 36VAC in addition(18×2)to what was already present before. Because now we’re including both sides’ contributions; then again, do 3000+ rotations per second 54 total.

The following is a list of the most common systems.

  • 22 amp single phase = 24 VAC @ 1000 rpm
  • 32 amp single phase = 18 VAC @ 1000 rpm
  • 38 amp single phase = 18 VAC @ 1000 rpm
  • 48 amp single phase = 24 VAC @ 1000 rpm
  • 36 amp three phase = 16 VAC @ 1000 rpm
  • 50 amp three phase 18 VAC @ 1000 rpm

The answer to this question also depends on the voltage of your charging system, because as we mentioned earlier, it’s not a good idea to overload any one component in your motorcycle’s electrical grid. 

If you’re using a 12-volt battery and alternator, then you’ll want an amp rating that’s no more than about 120 amps (or 1440 watts), but if you go up to 18 volts, then the stator can put out twice as much current without overloading 240 amps or 2880 watts. 

Just make sure whatever model number you choose can handle that kind of load. Otherwise, it might not last very long before burning out and needing replacement. And don’t forget that if you have accessories like heated grips, a power outlet, or even a heated vest, then you’ll want to add their amperage ratings into the equation as well. So be sure and read over all of your product manuals carefully before making any assumptions.

Jim Harmer

I am Jim Harmer and I am in love with the outdoors. I share all the information I know on all activities I like doing in my home in this website. You are welcome to read and reach out for more information.

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