Duracell Ultra Flooded 875CCA BCI Group 3EH Heavy Duty Battery - SLI3EH at Batteries Plus
Amazon.com: One New Right & Left Hand Battery Box Set Fits John Deere 3010 3020 4000 4010 4020 4320 4520 4620 Models Replaces AR34189 AR40210 AR40673 AR40674 AR43141 : Patio, Lawn & Garden
Left Side Battery Box AR40210 fits John Deere 4020
TractorData.com John Deere 4020 tractor information
Viewing a thread - JD 3020/4020 battery box upgrade
Complete Tractor 1400-0402 Battery Cable Compatible with/Replacement for John Deere 4020, 500 Indust/Const AR28950
Used Battery Box - Right Hand fits John Deere 3020 4320 4620 4010 4000 2510 3010 500 4020 2520 4520 AR26887
Traveller 12V 575A Heavy-Duty Battery at Tractor Supply Co.
Viewing a thread - JD 40 series 12V battery conversion and disconnect follow up (pics)
John Deere Tractor Battery Box L/H-220
Complete Tractor 1400-0402 Battery Cable Compatible with/Replacement for John Deere 4020, 500 Indust/Const
Used John Deere 4020 Tractors for Sale - 81 Listings | Machinery Pete
Viewing a thread - JD 3020/4020 battery box upgrade
John Deere 2510, 2520, 3020, 4020, 4520 (Gas & Diesel) Positive Battery Cable - The Brillman Company