Serious parasitic battery drain issue (I think)

  • So, during the summer I rode the sling several days a week, so didn't bother with the tender. Toward the end of the summer I added a Neutrino Aurora to power my curb alert and heated gear. Recently, I added a Pedal Commander, a Digital Guard Dawg and a USB charger with a built in voltmeter. So that is the sum total of electrically interfacing accessories on my sling. The first time I powered up the USB charger with the voltmeter I noticed it was only showing 11 and some change. I started the sling and it went up to nearly 14v, so I knew the charging system was working. I figured since the weather had cooled off and I wasn't riding as much, it just need to be on the tender more often. Since then it's been on the tender pretty much whenever I'm not riding it. BTW, the tender is the BatteryMinder 2012-AGM. The one the sling owners manual recommends. So fast forward to last weekend. I've had an ongoing issue with the Bluetooth in the Neutrino. Half the time my phone won't connect to it. I've been working with their tech support for some time on it. Last weekend they asked me to ship it back to them. I took the sling off the tender and removed the Neutrino. I reinstalled the FZ1 fuseblock I had been using before. The only thing I connected to it was the curb alert. I left the heated gear plugs and USB charger disconnected. This evening I realized I never put it back on the tender. So it's been off the tender and has not been started or ridden for a week. I plug in the tender. The "Weak Battery" light on the tender comes on and the led under the completely empty battery icon is lit. I unplug the tender, take the battery cover off and put a meter on it. 5.6V. Yikes! So now I'm waiting for the tender to (hopefully) get it back to 12.x volts. My next step is going to be to put an ammeter inline at the battery and see what the key-off current draw is. Anyone know whats "normal"? I assume less than a couple hundred milliamps, max. Anyone ever heard of a curb alert or digital guard dawg killing a battery in a week? I can't imagine how the pedal commander could be the issue, but I guess it's possible if the pedal position sensor has power all the time. Those are the only accessories installed right now. If it's not one of then, then I guess it's off to the dealer..

  • SZurlo if your dealer just washes his hands off it and blames it on aftermarket accessories which most do , try sourcing out an automotive electrical specialties garage. Your local mechanical garage will be able to tell you where one is in your area. They work more for garages and dealerships then they do for retail public as the garages will send them the electrical issues they can't figure out . A 12 volt system is a 12 volt system and most of them have experience with every make and model foreign or domestic usually . So the Slingshot will just be something cool and new for them but no problem for them. Some custom stereo shops have guys experienced with LEDS , remote starts , all kinds of aftermarket stuff too

  • SZurlo I would start by having the battery tested after charging. You didn't mention the battery's age but if it tests good then you can proceed to eliminate other possible culprits. Normally the pedal commander is only on when the key is on but unsure how that plays with digital guard dawg. Depending on how your second fuse block is wired it could be a problem and lastly from what I've read 100 milliamperes drain over 7 to 10 days will kill this battery!

    Hope this helps :)

  • SZurlo I would start by having the battery tested after charging. You didn't mention the battery's age but if it tests good then you can proceed to eliminate other possible culprits. Normally the pedal commander is only on when the key is on but unsure how that plays with digital guard dawg. Depending on how your second fuse block is wired it could be a problem and lastly from what I've read 100 milliamperes drain over 7 to 10 days will kill this battery!

    Hope this helps :)

    This is a 2019 Slingshot. Bought it new in August, so battery age shouldn’t be a factor. My second fuse box is on a dedicated line that runs straight to the positive battery terminal. The ignition sense is taken off the back of the lighter socket in the glove box. Currently the only thing connected to it is the curb alert. I just checked it and the tender has it up to almost 10v now so maybe it can be saved. Then I just have to figure out what’s draining it..

  • Well, the tender was able to resurrect the battery. Showing 13 volts at the battery right after I unplugged the tender. I put an ammeter inline at the battery. Only 13 milliamps. Some quick googling and it looks like the OEM sling battery is rated at about 30ah. That would last more than 2 months supplying 13 mA. In this situation it went from a full charge to under 6 volts in a week. Something else is going on. Going to leave the battery disconnected for a couple of days and see if the charge falls off with no load. Maybe it's just defective.

  • Well, the tender was able to resurrect the battery. Showing 13 volts at the battery right after I unplugged the tender. I put an ammeter inline at the battery. Only 13 milliamps. Some quick googling and it looks like the OEM sling battery is rated at about 30ah. That would last more than 2 months supplying 13 mA. In this situation it went from a full charge to under 6 volts in a week. Something else is going on. Going to leave the battery disconnected for a couple of days and see if the charge falls off with no load. Maybe it's just defective.

    is the 13ma with everything hooked back up? The one thing I would wonder about is the Digital Guard Dawg - I would assume that to do its job it must have power at all times.


    As a side note the last time my battery needed replacement I decided to buy one of these - Car battery tester - figured it would be nice to be able to know when a battery was shot without having to take it to be tested

    Cage Free - 2016 Pearl Red SL

  • is the 13ma with everything hooked back up? The one thing I would wonder about is the Digital Guard Dawg - I would assume that to do its job it must have power at all times.


    As a side note the last time my battery needed replacement I decided to buy one of these - Car battery tester - figured it would be nice to be able to know when a battery was shot without having to take it to be tested

    Actually, that was minus the curb alert. Hooked it back up. Now pulling 21mA with curb alert, pedal commander and digital dawg all hooked up. Still not enough to explain it discharging that much in a week. Very strange. Thanks for the tip on the battery tester. Might pick one up.

  • Last night I reconnected the sling to the battery. This morning it's showing 12.9. So now it seems to be fine. Not a warm fuzzy feeling. Will definitely be carrying a jump starter from now on...... I also order a battery tester and a clamp on ammeter so I can check the current draw with the battery connected, while starting, with the engine running, etc..

  • Last night I reconnected the sling to the battery. This morning it's showing 12.9. So now it seems to be fine. Not a warm fuzzy feeling. Will definitely be carrying a jump starter from now on...... I also order a battery tester and a clamp on ammeter so I can check the current draw with the battery connected, while starting, with the engine running, etc..

    OK! I am just asking why. All that you need is one of those cheap volt meters.

  • OK! I am just asking why. All that you need is one of those cheap volt meters.

    I have a couple of cheap volt meters. But you have to put them in series to check current and most are limited to 10 amps or so. Plus, most of them have a separate set of jacks for milliamps and amps. The millimap jack is usually fused at around 300-400 mA. If you put that inline in a circuit that only draws 200mA your fine, unless that circuit pulls more than that when it first energizes (charging capacitors, etc.) Then it blows the fuse in the meter. An inductive amp clamp can measure 0 to 100 or more amps with no physical connection to the wire. The reason I bought the battery tester is because it can do various specialized health tests on the battery that a regular DMM can't.

  • Sling II is still sitting after 5 or 6 weeks with 12.9 volts, with the small battery. It may even be the original battery. I bought a volt meter for it to keep check on the voltage, one day I will hook it up permanent, when I decide to start driving it full time after I get everything changed over.

  • To one of the bolts one of the the hood latches, which is welded to the frame.

    I'm assuming you tested the capability of said grounding point? Also I think (could be wrong) the hood hinges are attached to a sub-frame and not the frame itself. I would check the grounding point if a parasitic loss is a probable cause.

    When life knocks you down, calmly get back up, smile, and very politely say, "You hit like a bitch!"