UTV Battery Dead? How to actually keep a charge.
With spring right around the corner, it feels like great time to address your ATV or UTV battery and charging system. If it seems every time you let your rig sit for a few weeks and the battery is dead, this one's for you. In this scenario, EVERYONE blames the battery. Most of the time it is not the battery's fault - at least not at first. Almost every powersport vehicle has a stator type charging system. This is a great system and works well when you are not in low throttle positions. The average charging system in a powersports application is 30 to 40 amps.
Electronics Add Up
Step back and do a little math and things become clearer. Here's an example of just SOME of the items that are drawing power from your battery:
• ECU (Electronic Control Unit) = 2 amps
• Fuel Pump = 5 amps
• Approximately one 20-inch LED light bar = 10 amps
• Radio = 10 amps
• TOTAL = 27 amps
At only 27 amps of draw, you should be good right? WRONG. Your UTV should produce 30 amps at higher RPM’s but not at an idle. To produce 30 amps, you need to be at 3000-4000 RPMs. This is the point when the engine turns the flywheel fast enough to put out peak amps. So you think you will just hammer the throttle all the time and the charge should be good right? Wrong again. Remember all those goodies we listed above? Think of it like a budget. If you only have 30 amps and you spend them all on accessories, what's left? Not enough to charge your battery. At this rate, the draw you put on your battery when you started your rig will never get re-charged.
If you have trouble imagining of all of the electronics drawing power from your battery, take a look at your dash.
And let's say you're not putting a load or draining your battery completely when you are riding. You are still discharging your battery each time you let your engine fall below 3000 RPMs. Below 3000 RPMs, it is your battery that is keeping your rig going. For the sake of argument, let's point out that in the example above we only listed 27 amps worth of accessories. But then we said that at 3000 RPMs, you're producing 30 amps. That should leave a net profit of 3 amps, right? (Spoiler: 30 - 27 = 3.)
We also said the list was SOME of the electronics (and fuel pump and ECU aren't exactly optional). On paper it makes perfect sense but in real life, there are many many items drawing from your battery at all times. Here's a few more: the speedometer, factory HID headlights, tail lights, brake lights, horn. When your fan kicks on and off, that can take 15 amps by itself! And I hope you're enjoying that electric power steering - that can be another 10 amps.
Trim the Fat
So what can you do? First thing is first try to limit your electrical needs. Yes, a 50 LED light bar is bright and cool looking, but do you need that much light? We have four 4-inch led lights on our rig and it is plenty bright. The best part is they only take around 6 amps.
Next, do you need a thumping subwoofer and stereo that can blast you out of the rig while trail riding? Most people don't need to play music loud enough for an entire group. Tell your buddies to buy their own sound system. If it seems like a sacrifice right now, revisit the idea the next time you have battery trouble. It doesn't seem so bad when you're faced with not getting to ride because your battery is dead. If cutting back the accessories isn't an option, there is one more path you could take. You could install a high-output stator or an external alternator. But that's an extreme reaction and a topic for another time.
Maintain Your Battery
Proper battery maintenance is THE easiest way to ensure you're never let down. Yet, we see issues with this all the time.
"Maintenance Free" refers to fluid levels - you will still need to properly maintain any battery you use.
Make sure you are getting a quality battery and you are maintaining it. Most batteries today are AGM and say maintenance free right on the side, but that just refers to the fluid level in the battery. You still have to check the connections and put the battery on a maintainer when not in use.
Did you know that a battery self discharges at a rate of four to six percent every 30 days? Here's an example of a common scenario: There's 60 days of cold weather. Or just life happening. Thanksgiving, Christmas, then New Year's and you haven't gone out to ride in a while. Since it's cold and your rig hasn't moved, it's going to take twice as long the first time you try to start it up. In this real life scenario, your battery could be as low as 50% to 60%. The next time your start to curse your dead battery, think about how you've been treating it first.