it's better and easier to use a Battery Tender type charger for battery maintenance, buy another one.

 

Based on this thread;
http://gl1800riders.com/forums/showthread.php?t=167477&highlight=alternator+output+idle

where Stu states the alternator puts out 550 watts, and another person put the running load at 400 watts, that leaves 150 watts, or 12.5 amps left over at idle.

Assuming you have an 18 amp-hour battery, and no extra load, it would take 1.44 hours to charge a completely dead battery at idle. Of course, I'd not suggest letting your engine idle that long...

Just a guess, but I'd guess that 10 minutes of idling probably replaces the current you spent starting it, but not by much. Why not switch the battery tender over to the bike for a night each week or so? That will keep it fully charged and not load your engine and exhaust up with water, like you would do if you kept starting the bike for 10 minutes at a time.

 

Buy another battery tender, starting the bike and not running it to full operating temp is causing condensation in the crankcase, it is also putting undo load on the battery, the tender will keep your battery up and reduce potental problems. JMHO

 

How long do I need to idle the bike to charge the battery when not riding it for a couple of weeks?...... Am I using more battery to start it than I am putting back in with the idling? I have a battery tender (Schumacher) but am using it on my classic car right now.

A vehicle alternator is not designed to be a battery charger. It's purpose is to carry the electrical load while the vehicle is in operation.

 

I just move my battery tender
from bike to boat battery to lawn mower..
from time to time...
has worked for years

Running engine to charge battery is not good

 

Don't be a wuss - ride the bike. I rode mine to work yesterday. Of course, I live in Southern California....

 

I have been told that is the hardest thing on alternators. At least on cars.
Battery tenders are a lot cheaper than alternators.

 

Canyon Dancer,
As other have suggested, buy another battery tender. I have one and use it year round. If you keep the battery tender hooked up all year long when the bike is park over night or for days, your battery will last a very long time. Letting a battery get low on charge and charging multiple times will shorten its life. I bought a Schumacher Battery Tender at Wal-Mart for around $19.

 

CD, I have a Battery Tender Jr. that Carolyn got me for Christmas a couple of years ago. Not expensive, especially since Hal is having a sale now. It has a connector that attaches to the battery and sits behind the left side cover. To use it you just remove the side cover and plug it in. This time of year I plug it in after every ride. Don't forget the STA-BIL. It will keep your gasoline sweet.

 

The Battery Tender is your friend when you can't ride. One of the best maintenance items out there. Plug it in and forget about it until your ready to take the bike out on the road.

 

How long do I need to idle the bike to charge the battery

It has been said you cannot idle a bike to charge the battery WHY:shrug:

Because most bikes idle at no more then 900 RPMs a bike need to be running at least 1800 RPMs to put back in what your taking out. so an idle will never charge a battery. If you think you have all you have really done is start your bike abd let it idle and the battery was good enough to start each time.

But as everyone has said Battery tender

 

How long do I need to idle the bike to charge the battery

It has been said you cannot idle a bike to charge the battery WHY:shrug:

Because most bikes idle at no more then 900 RPMs a bike need to be running at least 1800 RPMs to put back in what your taking out. so an idle will never charge a battery.

The Wing is not like most bikes...

550 watts of alternator output at idle coupled to 400 watts of load means it will charge at idle.

I do agree that it's not a good idea to make a habit of though.

 

I'll hook the battery tender up

Thanks everyone, guess I kind of expected that idleing it didn't work, but knew I'd find out for sure from everyone. I'll do the switch-er-rue with the tender I have on the Jaguar. They sit right beside each other and generally get along pretty well!! I'm sure they won't mind sharing the Battery Tender either. :trike:

 

20 minutes

 

I would be more concerned with a 10 minute idle not being sufficient to warm up the oil to normal operating temperatures to drive off any moisture formed during the combustion process during cooler weather. Like the others said, get a battery tender or equivalent and hook it up to the battery to keep it topped off.

 

They sit right beside each other and generally get along pretty well!! I'm sure they won't mind sharing the Battery Tender either. :trike:

Back when my '96 Impala sat in the garage all the time, it shared the tender with an '86 Yamaha Fazer The tender spent most of it's time on the Impala, but once a week I'd put the tender on the Fazer. Usually the Fazer would be charged up within 30 minutes. Of course, the Wing's computer probably pulls more juice than the Fazer's did, and your Jag probably pulls less than my Impala did.

 

How long do I need to idle the bike to charge the battery when not riding it for a couple of weeks?

You don't. If your bike won't start after a few weeks of sitting, something is wrong with it. Mine starts right up after a month. If you are riding every couple of weeks you have absolutely nothing to worry about.

 

You don't. If your bike won't start after a few weeks of sitting, something is wrong with it. Mine starts right up after a month. If you are riding every couple of weeks you have absolutely nothing to worry about.

Depending on the age and condition of your battery, it may not be holding a charge very well, and lack of use of the bike, even for a few days, can significantly deplete the charge available for start up. Ideally, a vehicle that is battery started should not be left idle for more than 5-6 days at a time without properly operating it for at least 20-30 minutes -- or keeping the battery "tended" with something like an intelligent float charger.

A vehicle alternator is not designed to be a battery charger. It's purpose is to carry the electrical load while the vehicle is in operation.

True, but with at least 1100 amps available on the GL1800 alternators, it still provides an important service of “charging” your battery – providing the engine is run long enough at sufficient RPMs.

Buy another battery tender, starting the bike and not running it to full operating temp is causing condensation in the crankcase, it is also putting undo load on the battery, the tender will keep your battery up and reduce potental problems. JMHO

Completely agree.

 

Depending on the age and condition of your battery, it may not be holding a charge very well, and lack of use of the bike, even for a few days, can significantly deplete the charge available for start up. Ideally, a vehicle that is battery started should not be left idle for more than 5-6 days at a time without properly operating it for at least 20-30 minutes -- or keeping the battery "tended" with something like an intelligent float charger.

True, but with at least 1100 amps available on the GL1800 alternators, it still provides an important service of “charging” your battery – providing the engine is run long enough at sufficient RPMs.

Completely agree.

1100 amps! That's one heck of a 1800 alternator. I'm sure you meant to say 1,100 watts.

 

i am confident that your wings battery was fully charged within the first couple of minutes at idle

if u hook up the battery tender to your wing in the next few days it will show fully charged within a couple of minutes, if not i would suspect there is something wrong

 

I have a digital volt meter on my bike,When I fire it up the meter reads 12.5-12.9 then you can hear the Alt kick in and see the meter start climbing to 14.4-14.9 and then settle down at it warms up while I get my gear on..

But as a rule I try and keep the bike on a tender plus,just to keep the battery up to full charge all the time...

 

i am confident that your wings battery was fully charged within the first couple of minutes at idle

if u hook up the battery tender to your wing in the next few days it will show fully charged within a couple of minutes, if not i would suspect there is something wrong

I'm with cycledude on this. Considering you probably only crank the starter motor for a few seconds to start it, it will only take a minute or so to replace that amount of charge.

Just supposing for the sake of argument it takes 120 amps to run the starter motor, cranking it for 5 seconds consumes only about 1/6th of an Amp/hour capacity (120Amps*5seconds/60seconds/60minutes=0.16667Amp/hours). If the alternator can put out about 120 watts extra at idle as stated in the previous posts then it has just over 10 amps of charging current capacity (120watts/12volts=10Amps). Most of the charge has actually been returned within the first minute after the engine started in this example. (10Amps*60seconds/60seconds/60minutes=0.16667Amp/hours)

Depending on how many amps it really takes to run the starter motor and how long you actually crank, I would say it's a safe bet that your battery has almost certainly been fully charged back up within the first couple minutes, as cycledude stated above.

 

You don't. If your bike won't start after a few weeks of sitting, something is wrong with it. Mine starts right up after a month. If you are riding every couple of weeks you have absolutely nothing to worry about.

Thats what I was thiking:agree:

 

Exactly what Rocky said. Alternator putting out 14v at idle will indeed charge your 12.5v battery. My voltmeter shows battery a little over 12v and with engine running at an idle, alternator goes to over 14v.

 

Depending on the age and condition of your battery, it may not be holding a charge very well, and lack of use of the bike, even for a few days, can significantly deplete the charge available for start up.

Exactly, that is why if your battery will not start your bike after a few weeks, there is, as I posted, <something wrong>. BTW, lead acid batteries can last for 50 years, and many lead acid batteries used in commercial and industrial applications have twenty (!) year warranties. If a battery has been maintained, age is really a non-factor.

My 2003 has the orginal battery and never has been on a tender. Not one starting issue, even though it is stored outside in Maine. Bike will start easily even after a month. If I were putting a bike away for the entire winter, I might throw it on a tender, but for a couple of weeks? Not necessary.