San Diego-based Maxwell Technologies is supplying ultracapacitors to heavy equipment maker Caterpillar Inc. for use on what’s billed as the industry’s largest-ever hydraulic mining shovel.

Financial terms of the deal were not disclosed.

Capacitors store electricity for quick discharge. The Maxwell ultracapcitors that Caterpillar is using handle 125 volts apiece.

Some 98 of them are mounted aboard the mining shovel to absorb energy during brief movements, and then deliver that stored electrical energy on demand to supplement the main power system.

Caterpillar’s model 6120B H FS shovel weighs 1,400 tons and stands several stories high.

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