Sport Bikes banner
21 - 40 of 52 Posts

·
Registered
Joined
·
549 Posts
was i reading right or did someone here say battery tender is actually bad for the battery... why?
An uncontrolled battery charger would be bad, unless your battery is already in the shitter.

A battery tender is just a float charger, if the battery is fine, it doesn't charge it, it only charges when the battery depletes(from storage for example)

To ped, Yes the stator "charges" at idle, but there's not a whole lot of current being "charged". The faster the crankshaft spins, the more power the stator generates. This is why in the user manual it suggests maintaining an RPM of 5,000 while riding to maintain a good charge.

So yes, you are technically correct that it charges at idle. But no, it's not a full charge and if you idle for 3 hours you can still run the battery down.
 

·
Registered
Joined
·
884 Posts
An uncontrolled battery charger would be bad, unless your battery is already in the shitter.

A battery tender is just a float charger, if the battery is fine, it doesn't charge it, it only charges when the battery depletes(from storage for example)

To ped, Yes the stator "charges" at idle, but there's not a whole lot of current being "charged". The faster the crankshaft spins, the more power the stator generates. This is why in the user manual it suggests maintaining an RPM of 5,000 while riding to maintain a good charge.

So yes, you are technically correct that it charges at idle. But no, it's not a full charge and if you idle for 3 hours you can still run the battery down.
+1. If the system delivered full charging potential at idle, the voltage regulator would have to dump all of the exces power any time the bike was above idle. Most bikes, that's a very large percentage of the time the bike is running.

Any electrical power generated, requires work from the motor..... giving up HP to heat a load resistor is counter productive..... as far as I am aware, most bikes are 'trimmed' so close to no effective output at idle as to make no difference. That 3 hour idle scenario indicates the overall electrical system would be in a net 'discharge' state..... losing more power than being generated.

Seeing 14 volts and change with a fully charged battery in the circuit at 1320 RPM indicates a healthy battery, and charging system...... If the battery were discharged to the point that you had to bump start the bike, and you took that same measurement at the same RPM, I would not expect to see the same value until the battery was charged again.

Voltage readings are nearly equal to idiot lights, for charging system issues. Ammeters are much more effective tools.
 

·
Registered
Joined
·
492 Posts
A 2005, I'd change the battery regardless of what dealership says. If it isn't dead now, it will be soon anyway. Easy and relatively cheap way to see if the battery is the problem.

The battery on my 06 survived two winters with no charge (over 5 months) in a garage that hovered just a few degrees above freezing, and never saw a charger. Went to start it this spring, dead battery.

I charged it, was fully charged in less than an hour, bike started great. Went to start it a week later, dead, wouldn't even take a charge.

A bike battery is NOT meant to last 6 to 8 years! If you get 4 years out of one, you're doing well. Of course there are exceptions to everything but that's fairly standard.

Batteries will last the longest with regular use, which implies almost constant charging. Let a battery sit for too long, it dies. Even storage instructions for the battery specify to charge it at least once a month. Which kind of implies that a battery tender will help keep a battery alive, since it does exactly that. Monitors and charges as needed...
 

·
the joke is in your hand
Joined
·
8,594 Posts
Why would a manufacturer spec alternator output wattage at X rpm then? (usually around 7000 rpm)

Why would my, and others, battery have died when running at low RPM in the heat with the fan on, if my alt was putting out max at 900 rpm?

I think the bottom line to the OP is this, GET THE THING TO A DEALER NOW!!! :cheers

I agree with not having to use a battery tender though. I live in the great white north and use my lawn tractor as a plow, and it doesn't need any type of tender in the winter, and in the long gap between seasons there's also no issue. Not yet anyway!?! :D
that's called the MINIMUM output. that means it should be at least 14.4 volts @X rpms at the very MINIMUM. that doesn't mean it isn't going to be 14.4V at idle also.

every bike I've ever owned is at 14v at idle. even my 1975 suzuki GT-550.

I think the OP's voltage regulator is going bad. it's job is to maintain the 14.4 voltage to the system even when the engine is spinning faster or slower.
 

·
the joke is in your hand
Joined
·
8,594 Posts
What are you saying about not to use a battery tender...... Did you know if the chemicals inside of a battery stop reacting they die..... There for the tender keeps a very very low charge if you will, even though its not a charge at all.... When using a battery tender you will keep the batter alive not kill it or harm it in anyway. First winter with my bike no tender battery went dead... Second year tender battery is still strong. Orig. battery. I leave bike hooked up and tender in bc your ECU will always use small amount of power with modern bikes. I will also add the the chemicals inside the batter react to different temp. as well. Buddy of mine does not use tender but keeps his bike around 45 degress in the winter. He has never had a dead battery. My garage is as cold inside as outside.
constantly charging a battery will ruin it faster than letting it sit.

lead acid batteries can last up to 5 months on a single charge.
the new AGM batteries can sit up to 15 months on a single charge.

cold temps preserve a battery longer than warm temps. this is also where a lot of people have the wrong idea to bring a battery inside where it's warm.
the warm temps make the battery loose it's charge at a faster rate.

a battery only needs charged once a month for 30 or so min if kept in cold areas. such as outside or in the garage.

one that is indoors needs to be charged every 2 weeks.
that's it, there really is no need for a tender.

this is an excerpt from Yuasa's website,

"If the vehicle is in storage or used infrequently, disconnect the battery cable to eliminate drain from electrical equipment. Charge the battery every two weeks.

For extended storage, remove the battery from the vehicle and charge to 100%. Charge the battery every month if stored at temperatures below 60° F. If stored in a warm area (above 60° F), charge every two weeks. Make sure batteries are stored out of reach of children"
 

·
Registered
Joined
·
884 Posts
that's called the MINIMUM output. that means it should be at least 14.4 volts @X rpms at the very MINIMUM. that doesn't mean it isn't going to be 14.4V at idle also.

every bike I've ever owned is at 14v at idle. even my 1975 suzuki GT-550.

I think the OP's voltage regulator is going bad. it's job is to maintain the 14.4 voltage to the system even when the engine is spinning faster or slower.
A voltage regulator can only decrease the applied voltage, by dumping the excess current to ground. By classification, it's a constant voltage source.

If you had 16V applied, it could regulate that at 14.4 for instance. 14.5? You'd 'see' 14.4. 13? You'd see 13. No regulation would be applied.

Below 12 and change, you'd see the potential on the battery supporting the system's needs so it is a sure sign that evil sh*t is happening when you see 8.5V. the battery is nearly drained, for that to occur and there is no support from the charging system.

The fact that the applied voltage varies with engine RPM tells me the alternator is putting out something..... whether that output is what the bridge rectifier and voltage regulator are expecting is unanswered at this point.
 

·
The Flying Finn
Joined
·
2,594 Posts
that's called the MINIMUM output. that means it should be at least 14.4 volts @X rpms at the very MINIMUM. that doesn't mean it isn't going to be 14.4V at idle also.
The specs I've seen mention wattage, not volts. And as we all know W=V*A...

This has been in reference to a bike being able to handle accessories on a cruise. ie. "That FJR has a 350w @ 5500 rpm alternator on it, so it can handle roughly 25 amps of total load including all lights, etc.(@ 14 volts)."

I've never seen an alternator rated by how many volts it can put out, as for the most part they're all designed for a 12V system, it would be a somewhat useless spec. Now if you're talking the number from a factory repair manual, speccing a minimum voltage @ x rpms to check an alternator and see if it's bad, then that's a different story.

Nevertheless, it's been mentioned a couple times in this thread that on two occasions the factory FZ6 alternator hasn't put out enough wattage at idle to maintain a charge on the battery. I even had the same thing happen on my R1... both times was in extreme heat and all low speed and/or idle conditions. Battery didn't have enough juice to start a few minutes after shutting off, bump started both bikes, ran them higher in the revs for 20 minutes, never another problem...
 

·
Registered
Joined
·
884 Posts
The specs I've seen mention wattage, not volts. And as we all know W=V*A...

This has been in reference to a bike being able to handle accessories on a cruise. ie. "That FJR has a 350w @ 5500 rpm alternator on it, so it can handle roughly 25 amps of total load including all lights, etc.(@ 14 volts)."

I've never seen an alternator rated by how many volts it can put out, as for the most part they're all designed for a 12V system, it would be a somewhat useless spec. Now if you're talking the number from a factory repair manual, speccing a minimum voltage @ x rpms to check an alternator and see if it's bad, then that's a different story.

Nevertheless, it's been mentioned a couple times in this thread that on two occasions the factory FZ6 alternator hasn't put out enough wattage at idle to maintain a charge on the battery. I even had the same thing happen on my R1... both times was in extreme heat and all low speed and/or idle conditions. Battery didn't have enough juice to start a few minutes after shutting off, bump started both bikes, ran them higher in the revs for 20 minutes, never another problem...
This plays into the design of the regulator circuitry.... as I desscribed the post before, at idle the alternator is at it's minimum capacity to generate current (and by extension, wattage). The amplitude of the EM field between the rotor and stator is at it's minimum strength. Spin it faster, and the rotor interacts much more strongly with the stator.....

Most alternators are rated in their most ideal performance mode.... marketing weasels are at work. If they state it gets X# of watts at 14 V at a given RPM..... you can bet that's the strongest reading they can get.

The electrical load from the motorcycle is a known quantity, by design.... the alternator/charging system is supposed to be sized to meet that need at idle, but it's not that uncommon for them to produce just a smidge less than needed. Probably balanced at or slightly below the point that the voltage regulator would trim the peak voltage.
 

·
Registered
Joined
·
807 Posts
Charge the battery until voltage stabilizes at about 17 volts, wait about 30 mins, check open circuit voltage. You should see around 13 v. If the battery then load tests ok, battery's probably fine. Put the battery back in the bike, run it to 5K rpm, make sure you have 14 volts charging. If you see the voltage you saw in the previous measurement or less, your charging system is prolly poop. If you see more, you're charging system is prolly ok and you need to run the bike more. You could also check to see if and when the system starts to charge the battery, (at what rpm) if you really wanna know. I would suspect charging to start happen between 1200 and 1500 rpm, but of course all that is crap if you have add-ons like grip warmers on, high beams on, etc. Of course, if it's under warranty don't listen to any of us maroons and take it in.
 

·
Registered
Joined
·
884 Posts
constantly charging a battery will ruin it faster than letting it sit.

lead acid batteries can last up to 5 months on a single charge.
the new AGM batteries can sit up to 15 months on a single charge.

cold temps preserve a battery longer than warm temps. this is also where a lot of people have the wrong idea to bring a battery inside where it's warm.
the warm temps make the battery loose it's charge at a faster rate.

a battery only needs charged once a month for 30 or so min if kept in cold areas. such as outside or in the garage.

one that is indoors needs to be charged every 2 weeks.
that's it, there really is no need for a tender.

this is an excerpt from Yuasa's website,

"If the vehicle is in storage or used infrequently, disconnect the battery cable to eliminate drain from electrical equipment. Charge the battery every two weeks.

For extended storage, remove the battery from the vehicle and charge to 100%. Charge the battery every month if stored at temperatures below 60° F. If stored in a warm area (above 60° F), charge every two weeks. Make sure batteries are stored out of reach of children"

Constant ON chargers, and trickle chargers have the effects on batteries you are describing.

A battery tender, is a 'smart' charger.... it does not provide constant current to the battery being 'tended'. It samples the charge on the battery throughout it's use on a battery, and adjusts it's input to the battery to match it's need.

Once the battery has reached a full charge, the tender shuts off, and simply monitors the voltage. When the voltage drops, the tender will turn on it's charger, at a very low current rate, and 'top up' the battery.

Once it's charged up, does it take two weeks or a month or 5 months to discharge to the point that the smart charger will come back on and top up the battery? Who knows, and who cares.

That's the beauty of the smart charger.... you don't have to sit there and make the call..... it's automatic. :boink

The cycle is very slow, and by design as stress free for the battery as possible.

You can do the same thing manually.... this is just a little more sure.

Mine's plugged into the bike about 50% of the time, as I also use the same charger to maintain my lawn tractor. Neither one has shown any charge time longer than 30 seconds or so, all winter.
 

·
Registered
Joined
·
6,267 Posts
I just find it interesting that all of the people I hear having battery problems, all use a battery tender... :eatpop
 

·
Registered
Joined
·
884 Posts
I just find it interesting that all of the people I hear having battery problems, all use a battery tender... :eatpop
I haven't had a problem, since I started using one.....

Best solution of all, is to ride year around and never need to store the bike.
 

·
Registered
Joined
·
6,406 Posts
Best solution of all, is to ride year around and never need to store the bike.

you absolutely right. and if you cant ride all year round you can at least pretend to in the winter. battery companies love motorcyclists.
 

·
Registered
Joined
·
884 Posts
Even with the tender, I still go out and start the thing about weekly, all winter... run it long enough to get to full operating temp, and cook out some of the condensation. Between that, and having increased the idle speed slightly to 1300 or a bit more, the bike's been zero hassle electrically.

The tender has made more of a difference with my John Deere X304 lawn mower, actually.... that's got a Kawasaki vee twin (500cc?) under the hood..... we've had issues with that since the second year with the motor charging the battery. With the mower on the charger 50% of the time, it's been absolutely flawless.

That engine layout is one of the oddest things.... take a twin laid out like a Moto Guzzi, then let the top of the cylinders fall 'forward' to the crank is in a vertical plane...... odd, but it gets the driveline parts all aligned with no 90 degree gear sets....
 

·
the joke is in your hand
Joined
·
8,594 Posts
jesus christ some of you are know it alls.

go look up how a voltage regulator works. it in fact, lets more amps/voltage into the system when there is a demand for it. for instance, when you turn on the headlights, the ac, etc etc, it allows more of the current into the system.

as a matter of fact, that is one way to test them. by turning on several things at the same time, if the lights go dim or even flicker, it's said to be not reacting fast enough and could be failing.

tenders,
look up how the tender works, it keeps charging but at a low rate and kicks on to a higher rate and back down to a lower rate. they will ruin a batter faster than if you just leave it alone. they are mearly a money making gimmick.

I even quoted Yuasa's website about battery storage. the don't recommend using a tender. only charging it once a month if kept below 60. and 2 a month if kept above 60.

I didn't pull this shit out of the air or make it up.
 

·
the joke is in your hand
Joined
·
8,594 Posts
The specs I've seen mention wattage, not volts. And as we all know W=V*A...

This has been in reference to a bike being able to handle accessories on a cruise. ie. "That FJR has a 350w @ 5500 rpm alternator on it, so it can handle roughly 25 amps of total load including all lights, etc.(@ 14 volts)."

I've never seen an alternator rated by how many volts it can put out, as for the most part they're all designed for a 12V system, it would be a somewhat useless spec. Now if you're talking the number from a factory repair manual, speccing a minimum voltage @ x rpms to check an alternator and see if it's bad, then that's a different story.

Nevertheless, it's been mentioned a couple times in this thread that on two occasions the factory FZ6 alternator hasn't put out enough wattage at idle to maintain a charge on the battery. I even had the same thing happen on my R1... both times was in extreme heat and all low speed and/or idle conditions. Battery didn't have enough juice to start a few minutes after shutting off, bump started both bikes, ran them higher in the revs for 20 minutes, never another problem...


you don't test a charging circuit by checking it for wattage. you are mistaken.

it's only voltage you are testing. there is no mention of wattage etc in any of the 15 service manuals I own.
also I already mentioned it, no bike I've ever owned has not had 14.4 volts when it's at idle.

when it says the minimum is 14.4 @ 5k rpm, that only means it has to be at least 14 at 5k to be considered ok.
that doesn't mean it isn't working while it's at 1300 rpm.
nowhere does it say that in any service manual that I've seen. it if really didn't produce enough power, everyone would be buying a battery all the damn time.
the electronics draw way too much power for the battery to keep the bike running without the alternator making up for it.
 

·
The Flying Finn
Joined
·
2,594 Posts
you don't test a charging circuit by checking it for wattage. you are mistaken.

it's only voltage you are testing. there is no mention of wattage etc in any of the 15 service manuals I own.
also I already mentioned it, no bike I've ever owned has not had 14.4 volts when it's at idle.
:D

From my previous post:

"Now if you're talking the number from a factory repair manual, speccing a minimum voltage @ x rpms to check an alternator and see if it's bad, then that's a different story."

Volts are useless to people trying to figure out how much of a load they can run in addition to the bike itself. For the purposes of this argument, it's relavent to know how much wattage an alternator puts out at idle vs. at peak, and it's relavent to know where that peak is.

It should be a roughly linear curve up to peak where it would likely level out (unless peak is at redline of course). Unless I'm missing something here, if an alternator can put out X watts/amps at 5,000 rpm, than it should put out ROUGHLY X/2 watts/amps at 2,500 rpm.

They obviously put out 0 watts/amps at 0 rpm.

So knowing all this, if one puts out 350w @7000 rpm, then it's possible that it puts out 50w @ 1000 rpm. 50w is only 3.5A @ 14V. And considering an 1157 bulb is 27w, were talking about only 25 or so watts left over to run the bike, let alone if a cooling fan cuts in.

So it is possible that idling a bike, without grabbing the brakes, and without having the fan kick in, *could* charge the battery a bit.... but I think it's easy to see how running a bike at/near idle speed in a real world situation, using your brakes a lot, and in a hot environment with the fan running, could easily result in a net loss to the bikes electrical system, which would result in a dead battery.

It doesn't matter how many volts you're showing at idle... if you're alt isn't putting out enough watts/amps to keep up with the demands, you'll end up with a dead battery.

:cheers
 

·
The Flying Finn
Joined
·
2,594 Posts
Mentions of watts with regards to motorcycle alternators:

FJRTech.com - Dedicated to the FJR1300 Enthusiast! 490w FJR alternator...

So . . . can an '03 fjr battery system support 96 - 120 watts? - Sport-Touring.Net

Maximum Kelvin for headlight bulbs - Yamaha FZ6 Forums - International FZ6 Motorcycle Community Forum This thread claims our alt is good for 310w @ 5000 rpm

http://www.sportbikes.net/archives/forums/showthread.php?t=141938 Here's a thread on our dear SBN that talks about the same thing... and they mention a service manual spec'ing watts at a certain RPM.
 

·
Registered
Joined
·
884 Posts
jesus christ some of you are know it alls.

go look up how a voltage regulator works. it in fact, lets more amps/voltage into the system when there is a demand for it. for instance, when you turn on the headlights, the ac, etc etc, it allows more of the current into the system. .
The regulator allows more current to flow, to try and drive the voltage back up to it's set point. I've been working on this type of cirtuitry for near 30 years. Volts are the result of current flowing through the load, which is some value of resistance..... when you turn on more devices, that total resistance tends to go down, which causes the voltage to sag.... the regulator can add more current up to the point that there is no more to add...... then the voltage sags regardless.

as a matter of fact, that is one way to test them. by turning on several things at the same time, if the lights go dim or even flicker, it's said to be not reacting fast enough and could be failing..
This is a load test of the total electrical system. It's not necessarily a test of the voltage regulator itself. When you jump start someone else's car and your motor loads up... it's because your charging system has taken on more load, right? Do you get excited if your lights dim under those circumstances? If you put a volt meter on your battery at the point that you hooked up the jumpers to another car with adead battery.... do you think you'd see 14.4 volts? That's a bit unlikely.

tenders,
look up how the tender works, it keeps charging but at a low rate and kicks on to a higher rate and back down to a lower rate. they will ruin a batter faster than if you just leave it alone. they are mearly a money making gimmick...[/QUOTE]

Again, all I've done for near 30 years is work with regulated power supplies that do this sort of work. It's clear you're not up to snuff on how minimal that float charge current is..... trust me, it's not enough to feel. milliamps.

I even quoted Yuasa's website about battery storage. the don't recommend using a tender. only charging it once a month if kept below 60. and 2 a month if kept above 60.

I didn't pull this shit out of the air or make it up.
So what's the difference in your mind between manually hooking up a charger that has a fixed current flow every two weeks or once a month, and leaving a much smaller current source attached, that shuts itself off when it's not needed?

As I've said, my tender may apply a charge for as long as 30 seconds, when I hook it up on a fully charged battery.... and typically doesn't apply any more charge until I take it back off.

YMMV
 

·
Registered
Joined
·
549 Posts
I just find it interesting that all of the people I hear having battery problems, all use a battery tender... :eatpop
If you NEED to use a battery tender on a regular basis, your battery is already bad.

Using a battery tender on a good battery will not make it go bad.
 
21 - 40 of 52 Posts
Top