I've been using the Meanwell rsp-500-15 for 2 years now as my exclusive plug in charging source, and my scorn for automatic charging sources has only grown in intensity since.
While it is rated for 500 watts, it regularly surpasses 600 watts when the battery is depleted enough.
I employ 45 amp anderson powerpoles to disconnect it from DC when not in use.
When I unplug the 120vdc but it is still connected to DC, there is a click as the overvoltage protection kicks in.
Or if I lower voltage faster than surface charge depletes I will hear the same click.
The rsp-750-15 and -1000-15 have features that the rsp-500-15 does not. The desire for 1000 or 1500 watts suggests to me this will be used not just for top charging but for bulk charging and the OP asked about 50 to 80% charging.
When Maxed out, my rsp-500-15 makes a lot of heat. The very high rpm 40mm fan is very loud. I added more fans and heatsinking to keep this fan from coming on at lower amperage outputs, and to extend its life. I would recommend additional airflow aimed over meanwell casing, for use when maxed out charging depleted batteries.
Perhaps add some of these to meanwell casing for additional heat dissipation:
https://www.amazon.com/ENZOTECH-Memory-Ramsink-BMR-C1-Heatsink/dp/B002BWXW6E/ref=pd_sim_sbs_147_1?_encoding=UTF8&psc=1&refRID=W5X67K562YY2AT558V1QMy voltage range on the rsp-500-15, with a 10 turn 1000 ohm bourns potentiometer, is 13.12v to 19.23v.
While I intended to use a wind up timer, I have never bothered installing one. But if I did, I'd want a 6 hour timer, as 4 hours would have the unit shut off early as my AGM battery takes no less than 3.5 hours for amps to taper to 0.5% of capacity once absorption voltage has been reached( usually 25 to 35 minutes at 40 amps), and with many partial state of charge cycles accumulated, can take much longer for amps to taper to 0.5% of capacity at absorption voltage.
