Mine charges at idle, but I suspect the charging current is quite low. You can't expect a bike to charge up a dead battery at idle. Also, if the battery is really dead it will be resistant to taking a charge at first. Put it on a charger (one with a 5 amp max) overnight and then see if it holds a charge.

 

It does not. That is the reason to have the battery on a tender throughout months when you are not riding it. It does not charge the battery for example to go out and start the bike every week or so thinking you are keeping the charge up. All anyone is doing by doing so is further hindering the status of the charge. Unlike a car where you have an alternator charging the battery. A bike's battery is charged by a rectifier. The rectifier needs a constant minimal amount of rpm's to properly charge the battery. I'm not sure how high the rpms needs to be. But, it's much higher and constant than idle.

 

Ok, this is full of wrong information

A rectifier does nothing but make an AC voltage rectified to a DC voltage. It does not provide the charge.

An alternator, stator, generator, whatever all create an AC voltage. Most all vehicles then have both a rectifier to turn it into a DC voltage, and a regulator to limit it down to somewhere in the vicinity of 12vdc.

On our bikes, the reg and rec are external, and packaged together. On most cars, they are packaged in with the alternator.

the charging system of your car, AND of your bike essentially work nearly identical.

The difference is the "power" of the components basically. Due to size limitations, low electronic needs compared to a car, and a few other things, the bikes system is pretty minimalist, and as such is also a little "fragile" in essense compared to that of a car.

It in fact DOES charge at idle.

As said, put a meter on it if you want proof. If it is providing over 12vdc, it is charging the battery.


To simplify, if you fired your bike up and let it idle, it would do so for hours, without the battery dying. Hence, it is charging. It would be a BAD idea, but it would do it.

 

Well that explains everything, I just got the bike a few weeks ago and its too cold to ride. So I go out every morning and let her run for a few minutes just to mess with it.

I have a 2amp charger hooked up now. Hopefully the battery is still good.

 

its too cold to ride. So I go out every morning and let her run for a few minutes just to mess with it.

I've heard that's bad for the bike and can cause moisture build up in the engine just to give you a heads up

 

I just ordered a new Shorai Batter. Should be pretty sweet once i get it.

 

If you start the bike in the winter it is best to let it fully warm up and you don't want to be doing it too much, but every so often isn't a bad idea. Just don't start it and turn it off. Let it warm up.

 

The battery is charging at idle

Just put a meter on my battery while the bike was idling and was reading around 13.3V. It reads 12.4 when the bike is off. Fwiw, the system is designed to keep a good battery topped off. It isn't designed to charge a dead one.

 

My bike (and all the bikes I have ever had) will charge at idle. However if your battery is low and it is cold it may be frozen. A frozen battery will not charge with the bikes charging system OR a charger. If the battery is frozen it is often junk, but sometimes you can bring them back by letting them thaw for 24 hours and then charging at 1 to 2 amps for 24 to 48 hours.

If your bike is not producing a charging voltage (13.2VDC to 15VDC) at idle you have other issues that need addressed (possible rotor, stator, wiring/fuse, or regulator/rectifier) if it is producing more than 16VDC at any rpm you have a regulator issue and can destroy your battey and/or ecu. My bike produces 14.2VDC at idle and peaks at 14.8VDC at roughly 3000 rpm.

 

Yes, the bike does charge at idle......... technically.

BUT..............

It is a BAD idea to use the charging system to charge a completely dead battery though. The charging system is pretty minimalist and is designed to maintain a charge, not re-charge. The stress put on the charging system components trying to re-charge a dead battery can damage them or drastically reduce their life.

Charge it with a proper charger or risk a large repair bill.




side note... it ALSO charges poorly at constant high RPM like on a race track. The draw is near as much as the system can provide. A weak battery or weak charging system will show up fast on a race track, as the bike will be hard starting before every session.

 

Right. The other person's question was ............. Does the bike Charge the battery at idle ? His question was not ................ Does the bike maintain the battery's charge while at idle ?

 

I know that was the question you answered. That's why I stated at the beginning of my post. " Right. " You simply misunderstood me. That was my point.:suicide

 

Thanks for the help everyone. Well I let the battery charge up.

Now its staying at a 12.7v when off, which is fine.
Once I turn the key to on (headlights and fuel pump prime) it drops to 11.5v and slowly goes down.
This part worries me, i'm pretty sure when the key is turned to on, it's supposed to be around 12.2v to 12.4v.

Hmmmm, I'm going to ride it Sunday, hopefully it works.

 

Get a new battery, that drop to 11.5 indicates lowered capacity, the battery isn't designed for deep discharge. So when a deep discharge does happen, the battery is usually done. You may be push starting it soon just to get home.

As mentioned before, use battery tender for storage. I just pulled my battery out and put it on a 50mA/h trickle charge yesterday. it was sitting at 12.4v - with the bike untouched since around October.

 

Just to expand upon what moto Joe had mentioned earlier.
The charging system has 3 components aside from the battery.
The power source, In the case of the bike it is an AC generator. The Rectifier (converts AC-DC or vise versa), and the all important Voltage Regulator!! This maintains a specific voltage no matter what the input voltage variance is. If you were to put a multi-meter across 2 phases of the generator(car or bike, the alternator/generator generates 3 phase AC)you will get x voltage at Idle, and if you now rev the bike up to 5k rpm that voltage will increase significantly.

Why does this matter? Well, the charging system does more than just charge the battery, while its charging its also running the rest of the bike. So lets just say at Idle you are producing 13.5v at X amount of amps. Since the bike is running and the headlights are on, and the injectors are going and the ECU is doing its thing, All this is taking away from your X amount of amps. And since your battery is stone dead you do not have enough current to charge it in that small amount of time idling. Also, if the battery is really dead, it draws soo much current from the rest of the system trying to charge that the bike will not run right. This is when you have a really fucked up battery!

Note: when you check the voltage on the battery terminals while the bike is running, at idle 13.xx, when you rev the bike you should see that voltage vary by a couple volts say 14.xx or 15.00v this is the upper limit of the regulator and is normal. This also facilitates better charging conditions, as does actually riding the bike vs letting it just sit there and idle..

And Joe, you have an excellent point about the probable damage as a result of trying to charge a battery that has as much juice left in it as a potato with 2 nails stuck in it.....

Cheers

 

Well I confirmed today that it is a dead battery. It started up when I left the house, rode about 40 miles and stopped to get some gas. Did not even crank over at all.

About to order a motobatt.

Just something I found interesting,

My friend bought his CBR600RR in 2005, stock battery and he has never heard of a battery tender at all.

His battery still works fine. It sits through every winter and just starts up in spring like its nothing. That to me is freaking crazy.

 

The battery would be fine sitting over the winter months, as long as the bike isn't started. The battery that I pulled to top off will/would have started the bike no problem. (just a little insurance, just in case the bike cranks a little longer to start the first time)

The reason your battery may have died, may be from the ocassional start you did, and the battery never got to recharge fully.

When you do get the new battery, measure voltage with the bike running, to make sure charging system is ok.

 

Its getting good voltage, its around 14+v above 3500rpm.

 

Anything over 12.6V and it is charging. 14.40VDC is the recommended maximum charge voltage for absorbent glass matt AGM sealed lead acid batteries SLA as typically used for motorcycles.

http://batteryuniversity.com/learn/article/lead_based_batteries

 

Good to know as mines charging at 14.8- 14,96 @ 3000rpm and started thinking the reg rec was on its was out (trackbike) as it also get almost too hot to touch...was dind somewhere external to fit it rather than under the seat...

Sent from my SM-G900I using Tapatalk

 

It does, and typically it's at lower voltage than 4,000 rpm and up. However, rather than start buying stuff and throwing it at the bike, go to Radio Shack, etc, and buy multimeter and some simple tests. You need a fresh battery. Charge it and let it sit overnight. Should be 12.6 or so volts. If not, it's not fresh. If you charge this current battery overnight, let it SIT for at least an hour, should be 12.6 or so. If it's less, replace it.

Then install the fresh battery, start the motor, and check voltage at idle (should be at least 13.xx) and at 4,000 rpm, where it should be 14+ volts DC, but on these GSXR's it will often be 15 volts. If it's under 14, the R/R is probably bad. BUT, before you buy an RR, unplug the stator cable, start the bike and check the stator output voltage from pin to pin, A to B, A to C, and B to C. All three should be over sixty volts at 4,000 rpm ( AC, not DC) If they are, you need to replace the R/R. Don't install OEM, it's shit, get a Rick's.

So, first get fresh battery, test output voltage at battery, then output voltage from stator.

As to charging at idle, as mentioned, the AGM battery likes 14.4 volts. What happens when you "charge" at idle is that you typically get 13.X volts, which is theoretically enough to make everything work, but it doesn't. The battery will not charge fully until you get charging voltage to over 14.

 

...................
As to charging at idle, as mentioned, the AGM battery likes 14.4 volts. What happens when you "charge" at idle is that you typically get 13.X volts, which is theoretically enough to make everything work, but it doesn't. The battery will not charge fully until you get charging voltage to over 14.

My K7 750 voltage straight after starting is around 13.8V and ramps up to about 14.4V in about 2 minutes. So my 750 is charging real well whilst idling.

 

Thread dig!

As was mentioned earlier, the question isnt just about voltage at idle- its amperage as well.

The stator is designed to provide power- without ruining throttle response at low RPM. So, in general, you will see good voltage at idle (1300rpm) but there will be very little amperage above what is absolutely required to run the bike. In other words, the battery will probably not see much amperage at idle.

Above 2800rpm, the stator is producing enough power for the bike, and possibly .5-1 amp additional, which can then charge the battery.

So, starting and running the bike at idle is not going to charge the battery at all, and will in fact drain the battery over time.

 

Sorry, but that's nonsense. Seems you don't understand battery charging methods, and electrical engineering 101.

 

Nice thread revival :lol

Since forever: Starting a bike or car on its battery power to let it idle with the goal of 'topping off' the battery is never worth it. The drain on the battery to start is more than the slight charge that the bike will generate at idle.

You can let your engine idle for an hour and charge the battery less than you would if you simply rode for 5-10 minutes at operating RPM... without your engine overheating from idling-away with no airflow over the rad.

That's why God invented chargers / tenders.