Falcon 2000 Captain reported safely returning to departure airport after experiencing multiple electrical system anomalies.

Narrative

During climb around FL320 I noticed on the synoptic page BATT 1 in Amber with a +134 Amp and Amber #1 GEN with  23.7 Volts. I communicated this with the SIC and wondered why we don't have a CAS message. Right after saying that we received a BUS LH Low Voltage Amber CAS. We proceeded with the checklist; turning off GEN 1 and tying the bus. We decided to return back to ZZZ. We started to receive radar vectors and a descent. A couple minutes after we noticed that the bus was indicating tied on the overhead panel but the synoptic indicated untied; therefore drawing down on the #1 BATT. About :10 [minutes] later Display Unit 1&2 failed along with the Secondary Flight Display and little by little everything on the LH Bus. Control of the aircraft was given to the right seat pilot. As we got closer to ZZZ we started to configure the aircraft and the slats/flaps would not come down so we used the slats. Normal gear didn't work so we needed to use gear extension. With a NO FLAP landing; speed  was 30-40kts faster than normal. Landing was uneventful and we taxied onto our ramp. We tried manual depressurization; which did not work. The aircraft slowly depressurized on its own on the ramp.