Sounds like Bubblegum Crisis.
- The Knight Saber's hardsuits were primarily monochromatic - Priss in blue, Sylvie in white, Nene in pink, Lina in green.
- They had interactions with the police (it's the same world as another series, called AD Police). Nene was a police officer as her "dayjob", and there were important secondary characters on the force.
- The badguys were not mutants, but rather rogue machines called Boomers. The powerful ones did have a material-manipulation power that looked pretty freaky - swelling, bulging, tentacles, extra parts, stuff like that.
- Sylvie, the leader, owned a lingerie shop. They used the shops delivery van as a transporter for the hardsuits and their transforming motorcycles.
- The intern/helper was Mackie, Sylvie's younger brother. He walked in on them suiting up at least once.
Note that there are two versions of Bubblegum Crisis, an OVA from the late 80s, and Bubblegum Crisis Tokyo 2040 a reboot released in the late 90s.
I'd have to rewatch them both, but if I recall correctly the hardsuits were explicitly battery powered in BGC2040 and it was a plot point. I don't recall any particular emphasis on the power source in the original BGC, but its been a long time.
Furthermore, Sylvie's role was much more active in BGC than BGC2040, where she was more like a mentor and/or puppetmaster.
Of the two, it's more likely you're recalling the rebooted series rather than the original.