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*).
 - 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.