2016 Polaris sportsman 570 drains battery while driving

WyattLemke25 · May 9

Having problems with the battery draining while riding. It has a new battery, it does have eps, a lightbar and a winch. Can ride it for an hour or more just fine, but eventually the battery runs down to the point it can't keep up with fuel injection and it'll sputter, limp, and die. It also throws codes for the throttle position sensor. I'm not sure if that is related or not. Any ideas?

Mech · May 9

First thing to check is whether your bike charging can handle all those loads. You need to use an amp gauge between the battery and charging wire, and check that there is still some charge going into the battery when things are turned on. You need to do that check at just above idle.

If the amps fall below about a half amp when it's at driving revs, then you need to turn some things off.

WyattLemke25 · May 10

Thing is, I never have any of them on. Previous owner put all the stuff on it. This has been happening with nothing on. Never use the lightbar, and only winch every once in a while for short periods of time. I've tested the voltage regulator and it seems to be okay, but Polaris doesn't make it easy, can't really completely test it. The battery is at 14.2-14.6 volts at 1700 rpm with nothing on. Thanks for your input! Has me baffled, don't know much about electric systems and whatnot.

Edited May 10 by WyattLemke25

davefrombc · May 11

Have you put an ammeter in line with the battery to see if it is taking any charge? you may be seeing charging voltage but that doesn't necessarily mean the battery is being charged.. Are the battery terminals clean of corrosion?. If there is too much corrosion there can be 14v at the terminal but the resistance from the corrosion will not let the current get to the battery. Most vehicles can run on the alternator alone once started , but many now require a battery be in the system to . The battery may be be just connected enough the system sees it and will run but as the battery draws down the system fails.. Newer electronic systems are a lot different than the old mechanical ones. . Clean terminals and connections and check with an ammeter to see if the battery is rally getting a charge. From there you will have some idea where to go next. What voltage does the battery show after being charged and let sit for a few hours with no draw on it ? the battery could be faulty. A fully charged battery should show about 12.6 volts a few hours after charging.

Another thing might be it isn't a battery problem at all, but something in the ignition or fuel system electronics heating up and failing after an hour or so of running. How do you restart the quad after it has shut down from low battery?

Yammy · May 11

Those are some good responses!

Another simple thing you can try, given the information above... disconnect the aftermarket add-ons like the light bar, bringing the machine to its Factory equipment and then run the machine and see if the battery still dies. If not then one of the add-ons is draining your battery. If the battery still dies, remove all unnecessary fuses disconnecting their respective circuitry... leaving only the engine circuit. Run the machine again and see if the problem goes away or continues to be present. If there's still a problem check your charging system and the wiring connections. I have seen connectors come off before.

If the problem goes away, then connect one fuse at a time and see if that circuit drains your battery to identify which circuit is faulty causing the battery discharge.

Example 1, if water got into a bulb socket and rusted-out (overtime) causing a short, your lighting circuit will be the culprit that's draining your machine and this happens only when you're running the machine and you're lighting circuit is energized (consuming extra power).

Example 2, if the light bar was added splicing into the lighting circuit/wiring and it's not waterproof... corrosion... grounding or shorting in that circuit can draw extra power even if the light bar is not used.

14 volts means that your alternator is putting out (good) voltage but that doesn't mean it's pushing current, unless measured as mentioned previously. If the battery is dying, I am certain the current is drawn from the battery. Your problem may be one of these two issues, either 1) your charging system/alternator is not working properly or issues with its wiring connections or 2) there is an added load from the axillary equipment or a short in a different circuitry causing extra draw (not related to the charging system).

It's normal to throw a code if systems are starved of power and don't operate properly... regarding your throttle position sensor.

Let me know if this helps!

Yammy

Yammy · May 11

By the way if you're charging your battery with a charger hook into a wall outlet and then starting from there, running the machine... it takes about an hour to drain your battery if power is being supplied/consumed from the battery rather than the charging system.

So to me this means that you're consuming the battery power as soon as you start the machine ("rather than from the alternator or the charging system"). Unless there is extra power draw (that the alternator alone can't handle on its own) that it's drawing the battery dead as well caused by faulty wiring, the issue will be the alternative/charging system.

I have seen alternators put out full Voltage but fail under a load test/ current draw. Use an ammeter or get it tested. This is usually caused by a bad rectifier/diode.

Yammy

WyattLemke25 · May 11

Thanks for the great responses! I'll have to look into them later today. To answer Dave, the battery is clean and when charged it sits around 12.5. The 2-3 times that this has happened I've let it sit for a bit, then limp it back to the trailer get it home for a charge and it's all good. That tps code lingers sometimes. I do get the Lo 10.6 display on the speedo when the battery gets below around 11.5. Previous owner rode it pretty hard, it has 2100 miles and almost 200 hours, was rode fast and hot. I think I might mess with the accessories and see if anything is the matter there. Just been hard to diagnose when nothing really happens when it's idling. It's like when I'm searching it knows and behaves itself haha

davefrombc · May 11

With an ammeter in the circuit look to see if there is a draw with the key off. If there is , disconnect the voltage rectifier / regulator. If the draw stops you found the culprit . If I diode blows you very well could be showing charging voltage but with a large ac ripple . Alternators put out 3 phase ac. The rectifier turns that into dc which the regulator limits to charging voltage , typically 13.2 to 14.5 v.

If a diode goes open there will be a large ripple in the charging voltage but if it blows shorted you will not only have the ripple charging and all the unstable electronics that goes with it , but key off the battery would drain back through the shorted diode.

Doing a bit of search brings up several sites where people are seeking help with Polaris rectifiers / regulators.

I didn't think to mention this when I posted. Yammy may very well have hit on it .

Mech · May 11

Yeah well it does sound like a flat battery problem, though Dave's suggestion it could be mechanical or fuel is quite apt: it's been known to happen. I trust this thing isn't overheating to near seize ? Some of your other observations suggest battery though..

A simple way to check your charging system is putting out enough(or some) current, is to connect your gauge to check the voltage, it should be above 12.4 after an hour off the charger and with everything turned off, then start the engine and check the voltage goes to the 14.5v at 1700revs after a minute or less, then turn your headlights on and check the voltage stays over about 13.5, if it drops below that voltage, give it a few more revs and see if it can get to 13.5 with the headlights on. If it can run the headlights and still keep the battery voltage up to the minimum charge voltage(13.5), then the charging system is working and should be fine when you aren't using any of the extras such as lightbar.

It's also a good idea to check the voltage at different revs. Some bikes go up to 14.5 volts just above idle, then the regulator cuts in and regulates them to 13.5, and at anything above just about clutch engaging speed, they stay regulated. You may have a fault like that, but with a defective regulator draining or cutting all current at higher revs.

If it can't keep the voltage up to 13.5, under the load of the lights, at all revs, then there is a problem with the charging.

If the charging is fine, perhaps it takes about an hour before some electronic component gets hot and causes an issue.

To test that, you could run the bike with the headlights on, and see if it runs flat quicker than the hour. If it stays running for the full hour, then dies with a flat battery, then it would point to the heat effecting the electronics.

If it dies sooner with the headlights on, then it's not charging enough.

WyattLemke25 · May 11

Y'all typing essays trying to help me haha. Appreciate it much. Have some bad weather so unfortunately can't be running it much today. It doesn't really overheat, no temperature warnings ever come up, but it does get pretty hot. I've got it on the charger in the meantime to look into it tomorrow when its nice out.

Phil_Shifley · May 13

I bought the wife a KLR250 three years ago. She never really got into riding it so I'd try to ride around the community on a 20 min ride once a week or to work once a month to keep it from sitting. It had a battery tender pigtail when I bought it. If I did not ride it weekly, the battery would drain/draw down enough to not crank. I bought a new battery from ebay and reinstalled the same pig tail when I put the battery in. I had same issues with battery drawing down if I did not drive weekly or keep on battery tender, no crank after sitting over a week. I pulled the positive cable and inserted a meter which showed no current draw with the key out of ignition switch.

I ended up selling it last summer to fellow that I used to wheel with and let him know about battery issue.

A couple months of the same issues I had he bought new battery from auto parts store, had same drain/no crank issue.

He took his new battery out, took to store he bought it to have tested, which tested OK.

He reinstalled and said he was in a hurry forgot to put the battery tender pig tail back in as he did when he installed his new battery.

He now did not have the problem with battery drawing down.

He had bought a name brand Battery Tender after getting the bike but did not put the new pig tail on the battery because the bike already had one. Once he saw the battery was not draining and only difference was the pigtail, he compared the one that was on the bike with the one that came with his name brand battery tender and they were slightly different in appearance, the one that had been on the bike was not an actual Battery Tender brand. He installed the name brand pigtail and has not had an issue since.

I never would have thought that the pigtail was the problem and only guess it was poor dielectric quality rubber that had just enough current leeching through to drain the battery but not enough to melt the pigtail .

WyattLemke25 · May 13

After a full day of sitting, the battery has not drained. I just put on an off brand tender cable on this winter but just took it off when I charged the battery because it didn't work with the trickle charger for whatever reason. I've had issues before putting it on. I really just need to get it out to get a good feel for exactly what's happening and do some tests, but I haven't and won't be able to take it out for a few weeks.

Yammy · May 14

Thank you Dave!

I won't go into the detail of diode operation but they can partially fail with a skew in its operating range and functionality. Still causes problems.

Wyatt, also check to see if any wiring harness (that comes in contact with a hot engine part or Muffler) has melted insulation and possibly causing a short. Excessive vibration can cause wire insulation rub and shorting. Keep those in mind while inspecting the wiring harness. I would inspect the aftermarket wires that were put in place (sometimes) without a thought of where and how to run the wires.

Good luck!

Thanks to all of you that are helping! It's kind of fun being part of the community!

Cheers, Yammy.

97s-dime · Tuesday at 02:04 PM

check for parasitic draw... this happens with cars all the time. one of the aftermarket items could have a bad coil or switch pulling amps even when the item is off.