Some estimates place the maximum around 650 volts.
Electric eels produce two kinds of electric discharges.
Smaller discharges of 1-10 volts are used for navigation and communication. The large shocks are for defense and to stun prey, which they can only eat when it is not moving. The eel's electric organs are stacks of thousands of electric disks that run the length of its body. Each disk generates only a fraction of a volt, but when they all release together the shock can be enough to kill a human. Inc. All rights reserved.