This programmable hook is Iinspired by TEKZO haydrop.

So you could use it to drop hay for your horse or release anything else at a specific time.

BOM (affiliate links)

• CN101S 12V Timer (use S-Variant for 1s interval)
• Electronic Lock 12V
• 3S Charger (choose one)
  • slow charger
  • fast charger IP2368
• 3S BMS (choose one)
  • BMS1 
  • BMS2 
• 3* 3x18650 mounts
• 6* 6.3mm flat receptacles 
• car fuse 5A
• 12* M3 heat inserts
• M2,M3 and M4 screws Set1 and Set2
• 9x 18650 Cells (in 3S3P config)
• cables

Notes

• the charging boards and BMS can get quite warm, so I limited the IP2368 to 30W, alternatively you could use a more heat resistant filament like ABS or ASA
• the IP2368 is bidirectional, so you can also use it as a power bank
• there are two BMS mounts, choose the one fitting your BMS
• there are two backside variants, choose the one fitting your charger
• the backsides have a little window for seeing the charging-LEDs, I printed the windows in transparent PETG
• you can insert 2xM4 nuts mid print in the hook extension, the print profile pauses at the right layer
• inside photos are from a little different prototype