Kubota M8540 NARROW Operator's Manual page 36

16 OPERATING THE ENGINE
(1) Dead battery
(2) Lay a damp rag over the vent caps
(3) Jumper cables
(4) Helper battery
A This machine has a 12 volt negative (-) ground starting
system.
A Use only same voltage for jump starting.
A Use of a higher voltage source on tractor's 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.
A Do not operate the tractor with the battery cable
disconnected from the battery.
A Do not operate the tractor without the battery
mounted.
A Do not operate the tractor with the battery dead.
Charge the battery fully enough before operating the
tractor.
Otherwise the tractor might malfunction.