Give more energy to soldiers' attack (8)

I believe the answer is:

recharge

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'give more energy to' is the definition.
I can't judge whether this defines the answer.

'soldiers' attack' is the wordplay.
'soldiers'' becomes 'RE' (Royal Engineers).
'attack' becomes 'charge' (charge is a kind of attack).
're'+'charge'='RECHARGE'

Can you help me to learn more?

(Other definitions for recharge that I've seen before include "Give new power" , "Replenish power supply for, say battery" , "Pass on cost" , "Fill again (glass, battery)" , "Top up (battery)" .)

I've seen this clue in The Guardian.

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