Free Shipping $199+
LithiumBatteryz

KTM 125 Battery

2021–2027. The OEM battery case the 125 takes, the lithium that drops into it, and every model year we have on file. One case across the whole run.

Your Ride
Year
Make
Model
Change any box to look up another bike.
Your ride

2027 KTM 125

Not yours?
OEM battery
ATZ5-XManufacturer fitment list
Case family
ATZ5-X12V starter case
Fits all years
2021–2027same case every year on file

The KTM 125 takes the ATZ5-X case. The Antigravity ATZ5-X is a drop-in for that case: 170 cranking amps, 1 lb.

See the Antigravity ATZ5-X
Fits your bike
170CA
Antigravity ATZ5-X 12V Dirt Bike Battery 170CAStarter
Antigravity

Antigravity ATZ5-X 12V Dirt Bike Battery 170CA

12V·170CA·1 lb
$120
$160Save $40
3-yr warranty · Ships in 3-5 days

125 battery by model year

2021–2027Your year · 2027OEM batteryATZ5-X12V starter caseWhere it comes fromManufacturer fitment listLithium that fitsAntigravity ATZ5-X →

2 trims covered: 125 SX, 125 XC.

Shop all KTM Dirt Bike batteries

What the 125 needs, in plain English

Every 125 from the first 2021 model through 2027 starts on the ATZ5-X case, a 12-volt starter battery. KTM ships it with a lead-acid battery that starts to fade after two or three seasons of short rides and off-season storage, and that is usually the day a rider goes looking for something better.

The lithium drop-in is the Antigravity ATZ5-X: 170 cranking amps, 1 pound, the same case in lithium. Charge it with a lithium-compatible charger or maintainer for the off-season and it outlasts the lead-acid battery it replaces by years.

What size battery does a KTM 125 take?+
The ATZ5-X case, the same one on every 125 from 2021 to 2027. The Antigravity ATZ5-X is the lithium drop-in for it.
Will a lithium battery work in a 125 without changes?+
Yes, on a bike with a healthy charging system: the lithium battery uses the same case, the same posts and the same cables, and it drops in where the lead-acid battery sat. Bikes older than about 2000 should have their voltage regulator and rectifier checked first, since a failing one overcharges any battery and lithium tolerates it less. Fill any gap in the tray with the foam spacers most lithium dirt bike batteries include.
Do I need a different charger for a lithium dirt bike battery?+
Use a charger or maintainer with a lithium (LiFePO4) mode. A lead-acid trickle charger can push the wrong voltage profile, and a desulfation mode can damage a lithium pack. A lithium-profile maintainer over the off-season keeps it topped without harm, and the battery loses only a few percent of charge a month sitting on its own.