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EarthX Advanced Lithium Battery

#1 Best Seller
in The Ultimate KTM 390
9 reviews
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You've found it. This is (in our humble opinion) the holy grail of batteries.

Why? Well, it's the only lithium battery contender with a fully integrated onboard battery management system. Sound like marketing mumbo-jumbo? It's not. 

Brass tacks differentiators:

  • It will protect itself from over-discharging.
  • It will protect itself from over-charging.
  • Due to the built-in management system, you can use a cheap/generic charger, rather than forking up for a specialty li-ion charger. 
  • EarthX makes these bad boys in Colorado, which we think is pretty cool (as opposed to shipping them from overseas).
  • EarthX backs these up with a full value 2-year warranty, which is music to anyone's ears who has ever dealt with a "lemon" lithium battery. 

If you're on one of the larger adventure bikes and tend to run a bunch of electronics/heated gear through winter weather, you may want to consider upgrading from the ETX24C to the "Ultra Cranking" ETX36C for some extra cold season oomph. 

Here's what EarthX has to say about them:

Exclusive Features:
–Over-discharge protection (#1 killer of all batteries and other brands do not protect against this and void the warranty)

–Overcharge protection (Other brands do not protect against this and void the warranty)

–Built-in cell balancing technology (Other brands must use a special balancing charger in order to level the charge of each cell. Your vehicle is what charges the battery most of the time if you do not have built-in cell balancing technology, how is your battery balanced while using it?)

– Short circuit protection up to 1,000 amps (Other brands void the warranty if you short the battery)

–Excessive cranking protection (Lithium technology is different than a lead acid battery and needs to be protected from heat)

–2-year full coverage warranty (Not a prorated warranty that offers you the replacement at a discounted rate if they don’t void the warranty)

–Unique and exclusive design (Custom design with the terminals down the center and most models come with reliable brass terminal adapters for straightforward installation)

– Designed, engineered and assembled in the USA

Why choose an EarthX lithium battery? S P E E D
S= SPEEDY CHARGING- EarthX ETX batteries will charge 2-3X faster than a lead-acid battery.

P= POWERFUL and LONG LASTING- EarthX ETX batteries crank your engine over easily and will improve your starting performance as their nominal voltage is 13.3V compared to a lead acid which is only 12.6V. Also, EarthX ETX batteries life span is much longer than a lead-acid battery and can last years longer!

E= EXTREMELY LIGHTWEIGHT- EarthX ETX batteries are up to 80 percent lighter than their lead acid equivalents. Lighter weight = better performance! This saves an average of 2-3 lbs. for dirt bikes, 6-8 lbs. for street bikes and 10-20 lbs. for touring and cruiser bikes.

E= ENVIRONMENTALLY FRIENDLY- EarthX ETX batteries are environmentally and user-friendly. Nonhazardous, nontoxic, nonpoisonous. Will, not sulfate, will not corrode, will not freeze, will not boil over, will never need water added and will not spill acid EVER!

D= DISCHARGE RATE- EarthX ETX batteries have a much slower discharge rate than lead-acid, and the need to charge them is greatly reduced. 



  • ETX36C - 990/1090/1190/1290 Adventure/Duke/RC8/SM "Ultra Crank"
  • ETX24C - 990/1090/1190/1290 Adventure/Duke/RC8/SM
  • ETX18F - 390/620/625/640/690 Enduro/Duke/RC
  • ETX12A - 350/400/450/600/626 EXC/XC 
  • ETZ5G - 450 SX 2014+

Select your bike from the dropdown.



This product can expose you to chemicals known to the State of California known to cause Cancer or birth defects and reproductive harm. For more information go to: https://oehha.ca.gov/proposition-65

Customer Reviews
3.1 Based on 9 Reviews
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Filter Reviews:
    Chris Z.
    United States United States
    Perfect replacement battery!

    It was super lightweight but had the same form factor as my old battery so it was easy to replace. Has lots of cranking power too!

    Stephen F.
    United States United States
    Nice light weight Battery

    The install was a little tough, just seem to be a fraction bigger than the original battery. But once installed and hooked up it nice and powerful, like the fact that I can charge with my cheap charger.

    adam h.
    United States United States
    Wrong battery/ no support

    I'm not believing I'll be ordering anything from KTM twins anymore. The way your website is set up, it's confusing and I mistakenly ordered the wrong battery for my bike, when I plugged into details about my bike to see all the parts of ailable for it, which your website offers. Nothing on my order stated that the battery was wrong until I got a shipment confirmation. I tried to call, and I tried to contact via email to Jerome, but all I got were crickets. I am now trying to deal with bikebandit as they are dealing with your returns and other screw-ups.

    Scott S.
    United States United States
    Lithium battery

    Old battery lagged when the bike was cold. Not this one. Works like a champ. And KTM Twins got it to me fast!

    Norberto L.
    Costs more than it seems to be worth

    As per title above

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