What is a reasonable time to leave headlights on before battery drains?

BikerMass

Joined
Feb 2, 2009
Messages
13
Location
Dedham MASS
Bike
ST1300 2008
My ST1300 08 has never had a problem starting. However I left the lights on for 15-20 min by mistake (engine was not running) and the bike would not turn over. There was not enough charge left to turn engine. So I bought a new battery thinking the original battery that came with the bike was bad. I switch the old battery with a brand new battery and the bike started up immediately. I left the old battery with the dealer to test and reported that the battery was good.

Well last night I went to clean the windshield and left the lights on for no more that 10 min and the same thing happened. The only electrical add on is the powerlet harness (inline fuse) that connects to the battery and the wire runs under the gas tank. I also noticed that the fuse on the powerlet was busted. My assumption is that there is a frayed wire on the powerlet cord and
its grounding the system out.

I have removed the powerlet from the battery and will test to see if the same battery drain occurs leaving the lights on.

Any suggestions or similar experience will be welcomed.
 
I had a similar experience, turned out it was the little LED in a cigarette lighter type power plug I was using in the left hand fairing pocket, even with the farkle ( think it was a gps I had rigged up) OFF the LED would pull the battery down after two days.....

put a kill switch to ALL farkles from the battery

but now I've got most farkles on my ignition switched circuits (tail-light for extra running lights, and fuzz-buster is on switched circuit too) and the accessory circuit ( gps, cb, stereo ) so no longer have that problem....

my mini battery meter is still on a wire straight off the battery, along with the power plugs in the fiaring pockets and I use them to conveniently charge/jump the battery -- juice runs "backward" to the battery-- but I do have a switch on that circuit for safety...

my high powered hiway lights and fog lights are on independent circuits with switches on the dash shelf and have fuses.....

yeah if you had a blown fuse you had a short for sure, but that wouldn't drain the battery I wouldn't think as the fuse would get hot and burn out within a fraction of a second when the contacts were made....

I'm thinking your new battery wasn't fully charged?

Uh, it definitely doesn't take long to run the battery down with those headlights, I've done it several times fooling around installing and testing farkles, swithing things on and off for testing and having the lights on only momentarily but still run the battery down.....I have left them on absent-mindedly for about 5 minutes and still got a crank, but 10-15 minutes and you will not have enough juice to turn 'er over......

so I went ahead and rigged up some wires to the fairing pockets, one side has a power plug, the other just the + and - wire ends with twist connectors over them so I don't have to go through taking the seat off, and taking the side cover off and all that to jump 'er off, plus then fool around and put it all back on while the engine is running, and worry with cutting the engine off the use the key to lock everything back down, then find out the battery isn't quite charged enough to crank 'er up AGAIN!!!!!! ARGH! that can be very frustrating!!!

I have this neat rig that has two power plug plug ins, one on each end, just plug that in in a car, plug it in in the fairing pocket, flip my switch, check to make sure I have a good connection ( one of the plug ins has a series of LED's on it to tell you if you have a connection of not) then just WAIT about 5-15 minutes ( depends on how run down the battery is) NO NEED TO CRANK the car engine, just be patient as many people say car alternator has too many amps and will burn up small wiring on the motorcycle. Yet I've done that before with no harm done, but nowadays, since I've heard that , don't do it anymore. Car not running will jump off an ST no problem in 10-15 minutes even if bat is dead as a hammer!!!

hey and that power plug works good for a tire pump too, VERY convenient!!
 
This thing only has an 11 amp hour capacity battery. If I recall the stock lightiing draws about 11 amps. A load equivalent to 100% of battery capacity invokes Puekert's Law or something that means the battery is for all intents and purposes is dead after a few minutes.

There is no safe time limit to leave the lights on.
 
Not very long to run down the battery with the lights on. Found out first hand how long. About long enough to order a hamburger and eat it.

Don't use your kill switch to stop bike and forget to turn off the key. :doh1:


Gary
:04biker:
 
Best advice, as stated previously - don't leave the lights on when engine isn't running. For me, it's usually when I've started the engine to take off and then stop for a short comment with someone, shut off the engine with the kill switch to hear them (since it's only going to be for a few 'seconds') then . . . time goes by. :shrug2:

Less than 5 minutes for me, but . . . I've done it several times. Bike push starts really easy! :D (it helps if you're over 6' tall with long legs!)

Battery recharges just fine, I'm still on my original after 54k miles and maybe 6 or 7 full discharges.

When I'm not going to be riding for more than a few days, I plug a charger in while it's parked in the garage.

Shuey
 
Guys,

I agree that it only takes a few minutes to kill the battery with the lights on. Please tell me more about the push starting of the ST1300! I was told that it could not be push started because it is fuel injected. I always carry small jumper cables in by tool bag, and have used them several times over the years.

Can this bike be push started? If it can be, what is the best method?:bow1:
 
dannyk said:
It can be push started as long as you have enough battery juice to charge the fuel rail etc. if the battery is dead no can push start.
Click to expand...


Yep.

With a freshly discharged battery you can get it cranked with a small push.

After you have left the lights on for 30 mins or so, NO AMOUNT OF PUSHING can get it fired back up [in my experience]

I have done both, and I DO carry a set of cables.
 
Wikipedia says:
The battery capacity that battery manufacturers print on a battery is usually the product of 20 hours multiplied by the maximum constant current that a new battery can supply for 20 hours at 68 F? (20 C?), down to a predetermined terminal voltage per cell. A battery rated at 100 A?h will deliver 5 A over a 20 hour period at room temperature. However, if it is instead discharged at 50 A, it will have a lower apparent capacity.[47]

The relationship between current, discharge time, and capacity for a lead acid battery is approximated (over a certain range of current values) by Peukert's law:

DDuelin is right on. Assuming you have OEM bulbs on low beam - 2 bulbs x 45 watts each, running lights, tail lights, computer load, dash set, etc. I'm sure we're at 11 amps or more. Just the two headlights @ 90 watts/12volts = ~8 amps. Kind of makes a person mad to think that there is almost no reserve capacity. We could probably get a lithium battery for $600-800. :D
 
5-8 minutes is the limit on leaving the hadlights on..take my word on this. Usually after two tims the battery will be damaged. If your trip odometer and clock zero themselves out after starting the bike start shopping for a battery.
Another thing I have read somewhere on here is that if you push start the ST do it in second gear. It gives you a little more time to get a few rpm's out of the engine.

One other good thing to remember is ALWAYS have a spare key with you if you have to jump the bike. Can't put the parts back on without taking the key out of the igintion.
 
In my experience, the bike won't start in about the time it takes to get off the bike under the overpass to get out of a downpour. You use the kill switch and forget to shut off the ignition cause you've only had the bike for a month or so and this is your first rainstorm on the road. You use your spare set of keys to get your rain gear out and put it on with just a couple minutes chat with another set of bikers who pull in out of the storm to don their gear too. You saddle up and then notice the key is on so you hit the starter button and you get funny noises like a clicking, then the display flashes funny graphics, and other crazy things but she NO turnover.

All in all I think my battery was dead in around 7-8 minutes. There was just enough charge to make the clicking sound like an old solenoid and the display acting weird to make me NEW to the ST Beast, think it was a short or something else. So I called a local dealer, unknown to me, and he suggested checking for loose battery cables. Did that but that was the issue so I called AAA and they towed me to a dealer near my son's home. The mechanic was great and just charged the battery for a couple hours and sent me off without costing me a cent. He figured I had spent enough already for the tow. He confirmed that the ST will eat up the battery when not running.

Learned a valuable lesson. I don't use the kill switch anymore except when I tipped over at a stop sign. I carry jumper cables. And I take the key out of the ignition EVEN if I have my other set of keys in my pocket@!
 
Thank you guys for the solid advice and quick replys.

I'll buy some jumper cables and add that to my tool bag.

And remove the key everytime.

:biker:
 
Don't fiddle about with the electric windshield for more than a few minutes with the engine switched off, either! Guess how I found that out! :doh1:
 
BikerMass said:
Thank you guys for the solid advice and quick replys.

I'll buy some jumper cables and add that to my tool bag.

And remove the key everytime.

:biker:
Click to expand...
Make an extra key too. You have to have a key to get the battery cover on and off. If the key is needed in the ignition switch the cover can't be replaced.
 
dduelin said:
This thing only has an 11 amp hour capacity battery. If I recall the stock lightiing draws about 11 amps. A load equivalent to 100% of battery capacity invokes Puekert's Law or something that means the battery is for all intents and purposes is dead after a few minutes.

There is no safe time limit to leave the lights on.
Click to expand...

:plus1:Start it immediately! Mine won't start after about 3 minutes. :(
 
There are several other threads with push-starting advice and almost all of them recommend doing it in 2nd gear.

I've tried it numerous times in 2nd and 1st and have found 1st to be a better choice. I've lost count of how many times I've had to do this, but it doesn't take much to get the ST engine to turn over.

1st gear, BE SURE KILLS SWITCH IS OFF, BE SURE IGNITION IS ON, clutch in, straddle bike and push it forward (downhill preferred, level is 2nd best, up hill . . . turn the bike around :). When you're going as fast as you think you can go, sit, pop clutch while given'er some gas.

(Note, I have tried push starting with the kill switch ON and the bike never starts. Same thing with the ignition off! :doh1: Very, VERY tiring)

Shuey
 
RoadRiderG: "don't use the kill switch..." I'm sorry, but the MSF Format BC teaches ALL riders to use the bikes kill switch. Why? To leave both hands on the bars. Hey, as soon as you use the kill switch, just IMMEDIATELY turn that key off. Habit!!!!
 
You must log in or register to reply here.
Back
Top Bottom