The Kubota M4030 tractor uses a 12-volt electrical system. An exact model-specific battery CCA, Ah or group size was not confirmed in the sources used for this page.
ModelM4030
Years1986-1989
Voltage12 V
ConfidenceMedium
Voltage
12 V
Battery size
Kubota Group 31P wet battery
BA
Battery specification
Published model-specific battery data
System voltage
12 V
Battery designation
Kubota Group 31P wet battery
BCI group
31
RP
Replacement battery
What to match when buying
Voltage to match
12 V
Physical fit
Match case dimensions, terminal position and hold-down
ID
Model details
Identity and research coverage
Model
Kubota M4030
Equipment class
Utility/Agricultural Tractor
Model years
1986-1989
Research confidence
Medium
BUY
Choosing a replacement battery
Electrical rating and physical fit both matter
Keep the replacement at 12V, but do not buy on voltage alone. Confirm the physical battery size, terminal layout, hold-down and starting rating from the original battery or operator's manual.
1. Voltage
Keep the replacement at the verified system voltage.
2. Case size
Match tray length, width, height and hold-down style.
3. Terminal layout
Make sure the positive and negative posts are on the correct sides for the tractor's cables.
4. Starting power
Meet or exceed the published CCA when a model-specific CCA is confirmed.
5. Capacity
Match Ah and reserve capacity when those ratings are published, especially on higher-accessory-load tractors.
?
What battery size fits the Kubota M4030?
Quick answer
The published fitment is Kubota Group 31P wet battery. Match that designation plus the original terminal orientation, case dimensions and hold-down before buying a replacement.
Research note: Kubota parts applicability lists Group 31P wet battery for M4030. Aftermarket heavy-duty listings show 12 V 885 CCA / 150 Ah options, but those are replacement specs rather than confirmed factory ratings.
Disclaimer: Specifications are provided as a reference from published manufacturer, service-manual and reference information. Verify critical service values with Kubota or the correct service manual. Kubota website
