Need a little help, the book / series had humans with forbidden technology, if remember correctly it was like a energy storage that they adjusted to act as energy absorbers on their ships.
The other alien races hunt down any race with any type of the alien (AI) technology and destroy them. Also sometimes when the alien tech is activated sends a signal that alerts the other races about the tech.
You don't mention when you read the series, and this is a loose fit but enough elements matched to make it feel worth suggesting.
The Roboteer trilogy by Alex Lamb, published initially in 2015.
In the first novel, two factions of humans are at war (Earth, a theocracy with the weight of numbers, and Galatea - a colony world but with more advanced technology). Earth ships acquire the 'suntap', a new technology that directly pulls energy from the nearest star and uses it to power weapons; they can also be used to charge onboard antimatter reserves.
The Galatean ship Ariel, captained by Ira and with the roboteer Will on board, find the source of the suntap to be an ancient alien race called the Transcended. They discover that extended use of the suntap 'marks' the star for destruction, taking the race that is using it out at the same time.
The Earth factions are unsure of what information the Galateans acquired and pursue the Ariel through much of the novel.
The crew of the Ariel end up discovering the remains of a second race, the Fecund, which were wiped out by the Transcended. They repair a Fecund ship, significantly more powerful than their own, and use it to defeat the Earth forces and establish some degree of peace.
The later novels do involve some present-day aliens and ongoing threats.
