We have the designer of the Argus 4 electronics package as a member on this forum so he will correct anything I get wrong
1. The battery packs are thankfully held together with screws and easily rebuilt with new AA 2000mAh cells. The battery pack contains a BQ2010 “Gas Guage” IC that can be configured with a vintage TI utility running on a similarly vintage PC. The GAS gauge can become confused when the new cells are connected so multiple attempts may be needed. The BQ2010 utility permits monitoring of battery charge state and setting of cell capacities etc.
2. Charging of the battery pack just needs a suitable contact ‘shoe’ on which to place the battery, and a standard Delta V automatic NiMH battery charger. I bought chargers designed for radio control Ni-Mh battery packs. Just choose one that covers the number of cells found in the Argos battery pack. Set a sensible charge current, connect to the battery via the charging shoe adapter and away you go.
3. The ARGUS 4 came with Philips or “One for All” universal remote controls. The communications protocol is Philips RC5/RC6. I bought universal remote controllers and they all worked with the ARGUS 4 when set to Philips RC5 or RC6.
4. The ARGUS 4 had an optional Wi-Fi video streaming transmitter that fitted in place of the battery pack. The Antenna symbol just means that the camera is configured to output video to the Wi-Fi transmitter module. There were several other nice optional modules that mounted in the battery bay, including a DVR and IP Ethernet link adapter. Some Argus 4 models provided a composite video feed to the contacts in the battery bay.
There is plenty of knowledge of the ARGUS 4 on this forum so you should get some answers to most questions

I own four ARGUS 4 cameras plus several of the optional modules. Sadly no spare charging shoes…. I would buy some more if I could find them at a good price ! I have considered 3D printing some as they are not that complex and contain no electronics. The battery charging electronics are in the power adapter unit that plugs into the charging shoe.
Fraser