Kubota B2630 Operator's Manual page 35

(1) Dead battery
(2) Lay a damp rag over the vent caps
(3) Jumper cables
(4) Helper battery
A This machine has a 12volt negative (-) ground starting
system.
A Use only same voltage for jump starting.
A Use of a higher voltage source on tractors electrical
system could result in severe damage to tractor's
electrical system.
Use only matching voltage source when "Jump
starting" a low or dead battery condition.
OPERATING THE ENGINE 15