Flat battery

When it was home time my bike wouldn't start. Lights came on but not enough battery power to start the bike. I have heated grips but they are wired in to come on with the ignition so I can't have left them on. I am using the heated grips a lot and a sat nav, is it possible that they are drawing more power than the stator is returning? I can't think why the battery was Flat.

Could just be knackered rather than a charging problem. How old is it?

Its a 2018 bike. Could be but all tested fine at the service a couple of weeks ago. I know a lot can change in 2 weeks but I am hoping that it's still essentially sound and I have just asked too much on my commute from the battery

It's possible are you also using daytime running lights, using a multimeter might help diagnose where the power is going, it might be worth while letting the engine run with as much as you can switched off for the last 10-15 mins of your journey to dedicate the power to the battery

If you keep it somewhere where you can leave it connected to a battery tender when not in use I would recommend that.

Sat nav and heated grips won't draw enough to drain the battery while the bike is running

Sat nav and heated grips won't draw enough to drain the battery while the bike is running

That's not what I wanted to hear. I got rid of the Honda due to charging problems. If I have now got a kawasaki with charging problems I will be pretty pissed off

Sat nav and heated grips won't draw enough to drain the battery while the bike is running

That's not what I wanted to hear. I got rid of the Honda due to charging problems. If I have now got a kawasaki with charging problems I will be pretty pissed off

These things are sent to try us!

Crack out the multimeter and get testing

Although are you sure you just never left the park lights on?

Although are you sure you just never left the park lights on?

Sure. There's nothing left on. I don't know how to activate the park lights

My regulator rectifier just went and that stopped the battery charging whilst running. Could that be it?

Although are you sure you just never left the park lights on?

Sure. There's nothing left on. I don't know how to activate the park lights

As you lock the steering lock you can go one extra click and the park lights will be on

On some bikes its very very easy to do!

I did it on a bike once luckily it was at cadwell Park with plenty of hills to roll down to bump it off

Sat nav and heated grips won't draw enough to drain the battery while the bike is running

That's not what I wanted to hear. I got rid of the Honda due to charging problems. If I have now got a kawasaki with charging problems I will be pretty pissed off

How far is your commute?

How far is your commute?

26 miles each way mainly motorway and A road.

2 year old battery could be dead if it's ever been let run down. If it's been cold where you are that would definitely cause issues for a failing battery. You could charge it up and see if it does it again is the first and easiest step. Or if you wanted to take a more investigative approach then charge it up and let it rest for an hour or so and measure the voltage. If it's below 12.5v it's probably not great, if it's below 12v it's knackered. If the battery is good then measure the parasitic drain on the battery to see if anything is draining it.

Not good beans, could be reg/rec but I would expect it not to run as that happened to my old gsx550es when that fried itself but guess it could dump power from the battery when the ignition is switched on if it's on it's way south, other thing is battery could be slightly dud especially if it was very cold it may have just dumped its power but I'm no expert with electrics so I wouldn't take my advice too literally as I could be spouting shite!

Hope ya get to bottom of it soon

2 year old battery could be dead if it's ever been let run down. If it's been cold where you are that would definitely cause issues for a failing battery. You could charge it up and see if it does it again is the first and easiest step. Or if you wanted to take a more investigative approach then charge it up and let it rest for an hour or so and measure the voltage. If it's below 12.5v it's probably not great, if it's below 12v it's knackered. If the battery is good then measure the parasitic drain on the battery to see if anything is draining it.

How do you measure parasitic drain? It's the first time I have heard it

2 year old battery could be dead if it's ever been let run down. If it's been cold where you are that would definitely cause issues for a failing battery. You could charge it up and see if it does it again is the first and easiest step. Or if you wanted to take a more investigative approach then charge it up and let it rest for an hour or so and measure the voltage. If it's below 12.5v it's probably not great, if it's below 12v it's knackered. If the battery is good then measure the parasitic drain on the battery to see if anything is draining it.

 

How do you measure parasitic drain? It's the first time I have heard it

With the engine off disconnect the neg lead from the battery. Switch your multimeter to current (highest setting first if it's not autoranging) and connect between neg lead and neg terminal. You can then see how much current is being drawn with the bike turned off. You then start pulling fuses until the number drops and that's your culprit. The only thing you need to find out is what is an acceptable (normal) level of current with it off.

Another good test that's been useful on cars for me, not bikes yet is to measure the voltage drop on the earth to chassis connection. If you go to turn the bike over but it's really sluggish, lights dip etc, but the battery checks out fine every other way it's possible that you've got a bad earth lead or bad earth connection. To find out, switch the multimeter to volts, set it to 12v range and place the probes as either end of the earth lead. Then try and start the bike. If your lead is good then the voltage drop should be close to zero but I've had them read 1-2v which is definitely going to affect starting. You then replace the earth lead or remake the chassis connection if you've taken that in to account.

2 year old battery could be dead if it's ever been let run down. If it's been cold where you are that would definitely cause issues for a failing battery. You could charge it up and see if it does it again is the first and easiest step. Or if you wanted to take a more investigative approach then charge it up and let it rest for an hour or so and measure the voltage. If it's below 12.5v it's probably not great, if it's below 12v it's knackered. If the battery is good then measure the parasitic drain on the battery to see if anything is draining it.

 

How do you measure parasitic drain? It's the first time I have heard it

 

With the engine off disconnect the neg lead from the battery. Switch your multimeter to current (highest setting first if it's not autoranging) and connect between neg lead and neg terminal. You can then see how much current is being drawn with the bike turned off. You then start pulling fuses until the number drops and that's your culprit. The only thing you need to find out is what is an acceptable (normal) level of current with it off.

Another good test that's been useful on cars for me, not bikes yet is to measure the voltage drop on the earth to chassis connection. If you go to turn the bike over but it's really sluggish, lights dip etc, but the battery checks out fine every other way it's possible that you've got a bad earth lead or bad earth connection. To find out, switch the multimeter to volts, set it to 12v range and place the probes as either end of the earth lead. Then try and start the bike. If your lead is good then the voltage drop should be close to zero but I've had them read 1-2v which is definitely going to affect starting. You then replace the earth lead or remake the chassis connection if you've taken that in to account.

Fair enough, its sounds easy enough to do, but forgive my ignorance but which one is the current one? Is it the ohm sign one? I'm not too good with electrics lol

Fair enough, its sounds easy enough to do, but forgive my ignorance but which one is the current one? Is it the ohm sign one? I'm not too good with electrics lol

The ohm one measures resistance, the one you're looking for is the A for amps (or current). Start with a big number range and go down. I imagine you'd be looking at 50mA for a normal bike, maybe up to 100mA. If you see 1 amp or more you should investigate further. Just to reiterate though, definitely don't do this with the bike running.

If you look at this meter...

...the current ranges start at 10 (10 amps), 200m (200 milli-amps), 20m and 2000u (2000 micro-amps). You'd start at 10 amps which on that meter would require you to take the red lead, unplug from the meter and to plug it in to the empty socket near the 10Amax label at the bottom. If you get 0.05 to 0.10 you're probably ok.

If your meter looks differently to that either check in the manual or post a picture up and we'll try and make sense of it.

Fair enough, its sounds easy enough to do, but forgive my ignorance but which one is the current one? Is it the ohm sign one? I'm not too good with electrics lol

 

The ohm one measures resistance, the one you're looking for is the A for amps (or current). Start with a big number range and go down. I imagine you'd be looking at 50mA for a normal bike, maybe up to 100mA. If you see 1 amp or more you should investigate further. Just to reiterate though, definitely don't do this with the bike running.

Ahh right ok I got it now might have a play with mine during the day tomorrow see what mine comes up with.

Thanks dern

How do you measure parasitic drain? It's the first time I have heard it

 

With the engine off disconnect the neg lead from the battery. Switch your multimeter to current (highest setting first if it's not autoranging) and connect between neg lead and neg terminal. You can then see how much current is being drawn with the bike turned off. You then start pulling fuses until the number drops and that's your culprit. The only thing you need to find out is what is an acceptable (normal) level of current with it off.

Another good test that's been useful on cars for me, not bikes yet is to measure the voltage drop on the earth to chassis connection. If you go to turn the bike over but it's really sluggish, lights dip etc, but the battery checks out fine every other way it's possible that you've got a bad earth lead or bad earth connection. To find out, switch the multimeter to volts, set it to 12v range and place the probes as either end of the earth lead. Then try and start the bike. If your lead is good then the voltage drop should be close to zero but I've had them read 1-2v which is definitely going to affect starting. You then replace the earth lead or remake the chassis connection if you've taken that in to account.

 

Fair enough, its sounds easy enough to do, but forgive my ignorance but which one is the current one? Is it the ohm sign one? I'm not too good with electrics lol

NO. Ohms is for resistance.

If the meter is capable of reading current you need to select either “A” or amp or amps or mA. Also make sure it is on DC not AC.

Se picture below of meter selected to read Amps.

Also note there may be different sockets for the probes again see picture below.

With the engine off disconnect the neg lead from the battery. Switch your multimeter to current (highest setting first if it's not autoranging) and connect between neg lead and neg terminal. You can then see how much current is being drawn with the bike turned off. You then start pulling fuses until the number drops and that's your culprit. The only thing you need to find out is what is an acceptable (normal) level of current with it off.

Another good test that's been useful on cars for me, not bikes yet is to measure the voltage drop on the earth to chassis connection. If you go to turn the bike over but it's really sluggish, lights dip etc, but the battery checks out fine every other way it's possible that you've got a bad earth lead or bad earth connection. To find out, switch the multimeter to volts, set it to 12v range and place the probes as either end of the earth lead. Then try and start the bike. If your lead is good then the voltage drop should be close to zero but I've had them read 1-2v which is definitely going to affect starting. You then replace the earth lead or remake the chassis connection if you've taken that in to account.

 

Fair enough, its sounds easy enough to do, but forgive my ignorance but which one is the current one? Is it the ohm sign one? I'm not too good with electrics lol

 

NO. Ohms is for resistance.

If the meter is capable of reading current you need to select either “A” or amp or amps or mA. Also make sure it is on DC not AC.

Se picture below of meter selected to read Amps.

Cheers jrh I'll have a look at mine in the morning, it was just a cheap halfords one so it might not

Fair enough, its sounds easy enough to do, but forgive my ignorance but which one is the current one? Is it the ohm sign one? I'm not too good with electrics lol

 

NO. Ohms is for resistance.

If the meter is capable of reading current you need to select either “A” or amp or amps or mA. Also make sure it is on DC not AC.

Se picture below of meter selected to read Amps.

 

Cheers jrh I'll have a look at mine in the morning, it was just a cheap halfords one so it might not

Ok. Check out the edited post. Added an extra picture.

I would test voltage when running and at each of the first few 1000's revs ranges up too 6k?... When my rectifier packed up it charged at low revs not high revs, none of the tests pointed to wards it. Just my old school mechanic, given symptoms said rectifier.

Top tip here never jump start your bike from a running vehicle, it can blow rectifier. ***

Parasitic Draw:

Particularly If you are using same SatNav on both bikes I would be suspicious of that,

or if you have wired cam,

Alarms are a PITA for it.

Even the clock on some bikes can draw a surprising amount,

I fitted a solenoid to my bikes for auxiliaries so the power goes on and off with the engine. Except the TDM which has an alarm so already has a large parasitic draw.

As others say turning on parking lights when turning off, I know I did it the other day

If it has an alarm it has not been left in the wind so drawing more power from the battery.

Is your bike kept on Optimate or other intelligent charger? They often remove symptoms of dieing battery, you start it fresh from charge go for ride. Battery cannot hold charge for a couple of hours flat battery. Although I will admit am not a fan of "Smart Chargers".

I always consider it good practice to leave bike off charge overnight to see if it will start in the morning, my thought is if it starts of a morning it will start all day...

*** As I understand a rectifier takes any excess power created and ditches it as heat. The long and short of it is if other vehicle is running it try's to discharge all the power from other vehicle's alternator as heat. It cannot so just gives up the ghost, might not happen every time but once is enough.