The most common and most likely answer to this crossword clue is the 7 letter word POWERED
I've seen this crossword clue in The Daily Telegraph
P
O
W
E
R
E
D
More clues leading to the result POWERED
Buddy explains!

The straight part
We know that "supplied with juice" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case supplied with juice = powered.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does POWERED mean?
POWERED verb- To provide power for (a mechanical or electronic device).
- To hit or kick something forcefully.
- To enable or provide the impetus for.
- (of a device) Having its own source of power, or a named source