Oh cusswords!

[alwrmcusn]

I just returned from a four day trip and after unpacking, showering etc I went out to check the total miles ridden. Well you know how it works... insert key, turn on and when the LCD readout lights up, write down the trip meter mileage. Turn off and remove the key.

Ooops, I forgot the turn off and remove key part

Battery is flat! I connected my Battery Tender and it has been connected for about 24 hours and still shows the red led indicating it's charging. Will the Battery Tender recharge the battery or am I going to have to purchase a charger?

[Woody]

Battery tender not designed to charge a dead battery but it will and at 2 amps it takes a long time. Did you turn the switch on to see if battery had any charge at all after charging that long?

[alwrmcusn]

Just went out and checked. Not even a blink!! The battery is only about 6 months old. Whats the bestest for the leastest charger I can purchase? Cycle Gear is on my list for today anyway.

[Flyinfool]

A straight battery tender will not recharge a battery. Some (not all) of the tenders do have an included charge function, but as mentioned it is a very slow under 2Amp charge.

 

I would go out and get a small cheap charger (6-10Amp) to get some charge into that battery and then you can finish it off by riding or with the tender. Just do not forget about it on the cheap charger or it will cook.

If the battery was good before you ran it down, the run down should not have totally destroyed the battery, just knocked a little off of its future life span.

[Beau-Kat]

If you have an old battery around with even a few volts left in it and a set of cables you can hook them up in parallel and connect the charger.

 

The charger will think your bike's battery isn't totally dead and will begin to charge it.

 

After about 15 to 30 minutes, you can disconnect the old battery and the charger should continue to charge your bike's battery.

 

I've had to do this several times with these new fault detecting chargers that won't attempt to charge a flat dead battery.

[alwrmcusn]

I purchased a "MEGABOOST 6V/12V Fully Automatic Battery Charger/Maintainer" a couple of hours ago at CycleGear. When I connect it, it indicates that the battery is bad. The Battery is approx 6 months old.

I'm kinda sensing from the inputs that since the battery is completely flat/dead that it may be damaged?? Do I need to replace the battery? Or can I go to WalMart and purchase an el-cheapo charger and get it back to full power? Would I need to remove the battery to charge it? I need to get back on the road quickly. I have PGR missions I'm missing.

[Marcarl]

Like what was mentioned: put another battery into the circuit, one that has at least 10 volts in it, or hook up your car to it for a bit,,,,sooooo,,,, bring the car and bike close together, shut off the car, hook up booster cables positive to positive and negative to negative in that order,,, now hook up the charger to either battery and let it charge for a couple of hours. By this time the bike should have enough charge for the charger to see enough voltage and continue by itself on the bike. Do not start the car.

These new chargers will only charge if they see enough voltage, the one I have has to see 7 volts, yours maybe different. If there is not enough voltage it assumes the battery is toast.

[videoarizona]

Yep. You need to either zap the battery so the voltage is over 7 volts (old type charger, another good battery, etc..) or put another battery in the same circuit so the charger can be faked into charging. once your new battery is over 7 volts, it should come all the way back. You will lose some of it's life, but it should still last for a while!

[syscrusher]

My battery tender has an inline fuse, I think in the part that gets left on the bike, don't remember for sure now. Anyway, if I would try to turn the motor over while my tender was still connected the fuse would blow immediately. Of course with a blown fuse no more charging was possible.

 

Didya blow an inline fuse on your battery tender connection?

[alwrmcusn]

I did the car battery to bike battery and then connected the MegaBoost to the bike battery. It now is indicating that it is charging on the 12V setting. I have a choice of 2amp or 4amps and my friend recommended 2amps but that it would take a long time to charge back up. I did check the fuse (it's ok). I have the battery off the bike/trike as it is charging.

Thanks for all the replies and help from everyone. Just shows how well spent the $12 subscription is for us mechanical doofuses!

[jdross440]

I have had this happen to me before also. We all do things wrong sometimes when in a hurry or tired.

I hate these new "smart" chargers. They give me fits on my classic cars when I run the batteries too low too.

[djh3]

I guess my little Sears charger is an antique. Well I know its 30yr old or more. But I use it alot to power up relays to check out and lights etc. It brought more than one flat battery up in tthe last 4yr or so. Sooo I wonderguys if it has to sense 7v or whatever, could a 9v battery say be connected to fake it out?

[Tensilon]

On the other hand...

If you were already hitching your bike up to a car battery you could probably have just jumped it off of said battery, ran it for awhile until it acquired some charge through your charging system, and then put it on the smaller charger to trickle some charge into the bike battery, or let it run for awhile as I am sure the charging system on the bike would have put some charge into the bike battery at a pretty quick rate...

Larry...

[dacheedah]

I would think 2 amps is too low. If that does it I would go out for a nice ride.

[Monty]

On the other hand...

If you were already hitching your bike up to a car battery you could probably have just jumped it off of said battery, ran it for awhile until it acquired some charge through your charging system, and then put it on the smaller charger to trickle some charge into the bike battery, or let it run for awhile as I am sure the charging system on the bike would have put some charge into the bike battery at a pretty quick rate...

Larry...

 

 

This would be VERY HARD on your stator. Please don't ever do this. A flat battery will pull max current through the stator for a long time, which is not good for it.

[Venturous Randy]

This would be VERY HARD on your stator. Please don't ever do this. A flat battery will pull max current through the stator for a long time, which is not good for it.

I thought our stators charge at max load all the time and it is the regulators job to dissipate too much power going to the battery or electrical system.

RandyA

[Tensilon]

Randy, what Monty said and what you replied got me curious so I had to check it out and it appears that you are most generally right.

 

What I found is that the RSV charging system uses a permanent magnet type AC Magneto alternator. The output of the stator is dependent upon the engine speed and the force of the magnetic field. The magnetic field is constant. Increasing the speed of the magnetic field variation is what increases the stator output. The stator produces a certain output at a certain rpm. In other words engine speed is what increases the stator output.

 

The AC current produced by the generator is led through the rectifier inside the regulator/rectifier. The rectifier converts the AC phases produced by the generator to a single 14.4 Vdc output, a ground and a positive. Because the stator is producing power according to the engine speed, the stator output is too high all the time. This means that the output voltage of the regulator/rectifier would be way over 14.4 Vdc all the time, which would result in an overcharged battery and blowing electrical components on the bike that were meant to run on a voltage between 12 and 15 Vdc.

 

The regulator looks at the DC voltage across the battery terminals and short circuits a certain amount of the power that is produced by the stator to ground. This is regulated constantly, so the output voltage of the regulator/rectifier stays at 14.4 Vdc all the time.

 

So it would appear that running the bike to charge the battery will not overtax the stator as its output is more than enough to charge the battery and is in fact down-regulated by the regulator/rectifier constantly. At least that's the way I read it.

.

The main thing to remember when you jump start a bike with a car, is to not have the car running when you jump start the bike. The charging system on a car is a different animal than the one on a bike and you will likely fry your regulator/rectifier.

Any thoughts?

Larry...

[Flyinfool]

Your close.

The stator is a variable voltage variable frequency power source that has both voltage and frequency determined by the rpm of the engine. The Stator is always at it maximum potential. In a stock Venture, first or second gen there is a shunt type regulator. The way that the regulator works is kind of like what you said. The difference being that electricity is not pushed it is drawn. So with the stock regulator when the voltage exceeds it set point (14 volts in this case) it makes a connection to ground and that ground connection will draw as many amps as necessary until the stator can no longer hold the voltage. Whenever you exceed the amp capability of a power source, its voltage will drop proportionally. In this case the voltage drops to ~14VDC on the output.

 

 

In a stock system;

You are correct that the stator is always doing all that it can.

It is correct that the regulator is dumping off all of the extra power to ground.

 

Where the difference is, is when the battery is drained way down, and the engine RPM are up, the bike electrical system plus the draw of the battery can exceed the total available output of the stator. In this case the regulator is dumping nothing to ground because the bike plus battery is using it all up, the problem is that if the bike plus battery are asking for more amps than the stator has to give, its voltage will drop. It is this extreme amp load that will cause the windings of the stator to get hot and degrade the insulation on those windings. The stator may not fail right away but you have overheated it and weakened the insulation and you will thus have shortened its life. The stator will fail sooner than if you had never used it at or over its max amp output capability while charging a dead battery.

 

When jump starting, the reason you do not want the car running, and some people get away with having the car running is that the regulator on the bike is going to try to dump as much power to ground as it needs to, to try to maintain its set voltage. IF the cars voltage regulator is set higher than the bikes regulator, the bikes regulator is going to try to pull enough amps to drop the car down to the bikes set point. My car has a 200 amp alternator. The regulator on the bike is rated for around 40 amps. All of the magic blue smoke will come out of the bikes regulator before it can pull down the voltage on my car. If the cars set point happens to be the same or lower than the bikes set point, then there will be no issues with jumping from that car while it is running. This explains why some people have had no problem jumping from a running car. Others got away with it because the two were close enough and were connected for a very short time so things did not have time to overheat. It is just safest to not have the car running to avoid the possibility.

 

You notice that many times I mentioned a stock system, there are after market rectifiers/regulators for our bikes that do not shunt the power to ground and have a completely different way of doing everything. But that is almost a whole nuther post. My fingers are tired now.....