The John Deere 8120 battery size is listed as Group 31, 12 V, 13 × 6.81 × 9.44 in.
Battery sizeGroup 31
Voltage12 V
Case size13 × 6.81 × 9.44 in
John Deere 8120 Battery Specs
Battery size / group
Group 31
Battery voltage
12 V
Battery dimensions
13 × 6.81 × 9.44 in
Battery Spec Comparisons Chart
Voltage comparison
This model
12 V
Average
11.66 V
Low
6 V
High
24 V
Case length comparison
This model
13 in
Average
11.13 in
Low
7.75 in
High
13 in
John Deere 8120 Battery FAQ
Replacement battery recommendation
The best replacement battery for a John Deere 8120 tractor is the John Deere StrongBox battery, which is designed to meet the demanding specifications of John Deere equipment. It is known for its durability and reliability in harsh conditions
Battery voltage
The John Deere 8120 tractor uses a 12-volt electrical system with two batteries rated at 12 volts each
Battery group size
The official battery group size for the John Deere 8120 tractor is Group 31. This size is commonly used for many John Deere tractors and provides the necessary power for reliable starting
Battery CCA
The recommended official John Deere 8120 tractor battery has a Cold Cranking Amps (CCA) rating of 925
Battery location
The battery on the John Deere 8120 tractor is located underneath the right access step. You may need to open the flap and possibly remove the access step to reach it
Battery replacement steps
To replace the battery on a John Deere 8120 tractor, locate the battery underneath the right access step, open the flap, and if necessary, remove the access step by taking out the attaching screws. Then, follow the proper disconnection and connection procedures for the battery cables to ensure safety
Bad battery symptoms
Common symptoms of a failing battery in a John Deere 8120 tractor include hard starting or no response when trying to start, clicking sounds, and rapid battery drain. Additionally, corrosion on battery terminals can prevent proper electrical flow, leading to starting issues
Official information note
Mistakes do happen. Please check official deere.com website for official information.
