Looking for a bit of advice before taking a bike into the shop. 2023 Husqvarna FX 350. 45 Hours total. Unfortunately this bike has killed 3 batteries so far. One OEM, two Anti Gravity. The only modification done is an oem KTM / Trail Tech radiator fan.
I just bought a new Firepower battery and I want to figure out the issue before killing another battery.
So far:
I tested the stator - resistance between the wires, checking continuity to ground - it meets the specs in the service manual.
I tested for a parasitic draw, 0.13 milliamps, which is not significant.
I put the new Firepower battery in the bike with 13.2 volts. While running the battery shows 13.4 volts. With that in mind, I swapped the voltage regulator for a good working one out of a 350 XC-F, and the Husqvarna still only produced 13.4 volts.
At this point I plan to remove the fuel tank and check the ground wire. I'll also check out the main fuse, and see if there is possibly any corrosion on the connectors between the stator and regulator.
If anyone could help lead me in the right direction, or has had a similar experience I would appreciate any info. Electrical diagnosis is not my forte. Thanks.
Electrical diagnosis is also not my forte, but did you have the issue before the rad fans? I realize you've checked, but it is giving symptoms of a parasitic draw related to those. I would check for voltage to those when everything is off. Corrosion on the connectors would be my next guess. You're doing everything I would do 🤷♂️
It's probably the fan. The 350's stator doesn't put out much juice and the KTM fan has the biggest draw of all the fans. I put a stator on my xcf with the ktm brand fan and it's worked flawlessly.
If you want to test this. Put in your new battery and unplug the fan. See how long it lasts.
What brand fan are you running?
The XC bikes don't have a big enough stator to reliably run the OEM style kits with the SPAL fans.
It’s the OEM one with the spal fan
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I actually put the fan on from day 1 so that’s the only way it’s been ran. Sounds like I should unplug it and see what happens. I could also try to turn the temperature up to 200 so it runs less. It’s set at 185 now. But like others have said maybe it does need a better stator capable of handling the fan.
It’s just a little odd. This is my 4th 350 with a fan kit and this is the first one that’s had trouble.
It's my understanding that the previous gen 350s had larger stators... could be why you never had an issue before, but are going through it now.
Check the voltage with the bike off and then on. Maybe it's not charging properly. As other people said undo the fan and see if it fixes it. Look behind the front number plate I had to redo my starter connection up there because it was so corroded.
FWIW, I have a 2021 FX-350 and installed a KTM Powerparts Digital Fan Kit when the bike was new. Not sure if the '21 has the same stator as the '23, but I've never had a single issue with the battery. Still going strong after almost 5 years. I have the fan set at 195.
I have a 21 FX350 that has 200+ hours on a spal fan at 185 degrees with no issues, the 23+ have a smaller stator than the older bikes.
Try unplugging the fan or turning it up and see what happens, if that fixes your issue then you know that's the issue and if so I can link you some other fan options that have less amp draw than the Spal, good luck!
Try a voltage drop test, see what the fan draws when on.
If you factor what your charging rate is and compare that to the fan draw, should be easy to estimate draw rate.
Keep in mind that charging begins at a certain rpm, some bikes it's 3k.
If the draw rate exceeds charge rate or close, that's a problem, you'll also need to add in anything else that's pulling power, like headlight, excessive starter use etc...
You could get a digital volt meter, wire in an on/off switch and watch it during rides. I wired in an on/off switch with my fan so it doesn't run when the bike is off, constantly kicking on and off while sitting is a pretty big voltage draw.
Are you using a lithium battery tender between rides ?
Here’s the measurements I found.
Bike off - 13.06 volts
Bike running, fan off, 5,000 RPM - 13.42 volts - doesn’t fluctuate much whether at idle or with RPM
Bike running, fan on, 5,000 RPM - 13.35 volts
Just for comparison, these were the measurements with my 24 KTM 350 XC-F
Bike off - 13.2 volts
Bike running, fan off - 14.2 volts
Bike running fan on - 14.1 volts
Have yet to have a chance to check the fuse or ground strap. I don’t normally hook up the battery tender. I do have a lithium one. Sounds like I need to use it more often and turn the temp up on the fan.
It’s kind of a bummer that they would reduce the output of the stator on the new gen bikes. They have to know consumers are going to put a fan on an off-road bike.
This sounds like a failing stator. Not producing enough voltage to charge the battery.
Test the stator after you ride for 15-20 minutes it might be overheating and then shutting down.
Does your bike still run with the dead battery ? I carry a capacitor that I’ve had to wire across the dead battery to get my 2020 300 xcw back to camp. Was just curious if the capacitor is needed for all dead batteries on modern bikes with ecm’s or just ones that are shorted.
No, Stalled the bike during a sprint enduro test. Wouldn’t even make a click noise after that.
That’s a good idea, I’ll have to give that a try. I appreciate all the input from everyone.
So you just had it towed in. With the capacitor you can bump start it and ride it back. I was wondering if that’s what you did. It’s a good idea to carry one if you currently don’t. Not sure if this is the case with the XC bikes as well ?
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