Know before you go By the staff of Dirt Wheels

Look closely along the top edge of the tester. Those small LEDs indicate we are hooked up to a perfectly working battery. It’s also indicating our charging system is working properly. A few years ago Polaris added a SAE port so you can easily trickle-charge the vehicle’s battery. On this RZR, it made for an easy way to connect the tester.

There’s one thing worse than going out to your ride and finding it won’t start, and that’s not knowing why it won’t start! With the Optimate ( cranking power & alternator tester, you can definitely rule out any battery-related issues quickly before it happens.


It’s a small device that will tell you how badly your battery struggles to start your engine, if your alternator is charging properly, and how full your battery is when sitting. It can also warn you if you are having voltage regulator problems. For reference, if your battery volts drop below 9 volts when starting, your battery may be weakening. The tester will measure these cranking volts and store them for 20 seconds. 

This simple $44.95 device will let you know the condition of your battery as it sits, when it starts and while your vehicle is running. Take the guesswork out of the electrical-system issue with help from Optimate (


Two alligator clips or an SAE plug will attach the device to any 12-volt lead-acid or LiFePO4 battery. An easy-to-read display and a series of colored LED lights will be your window into cranking power as you hit the starter button, the strength of your alternator when the engine is running, and it will even show the battery’s condition when the engine is off. The easiest machines to test were the ones with an SAE plug that we could access quickly like on newer Polaris’. An aftermarket battery-tender lead will work, too.

After connected to your battery, you can instantly see the battery’s voltage, depending on which LED lights up. The reading is precise, indicating half volts from 12–15. A holding charge above 12.5 is best, and below 11.5 is bad and can cause a hard starting issue.

So, speaking of starting, the next measurement the tool will take is the volt draw during start-up. If the tool reads 8 or lower, your battery needs to be changed sooner rather than later. Finally, the tool will tell you if your alternator and voltage regulator are giving the battery the right amount of juice. The best range to be in is 13.5–14.5. Too little tells you the alternator/stator is bad. Too much means that the voltage regulator is not functioning properly. 


From time to time, there’s always that one vehicle in our stable that is always dead when we go out to start it or cranks slow on the trail. With the Optimate kit in our toolbox, the guesswork is over. In fact, we tried the tester on every vehicle in our shop this month. At the moment, all of our vehicles are starting and running great. Priced at $44.95, the Optimate tester was simple to use and gives us great peace of mind that we won’t walk out to a dead battery the next time we want to ride.

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