Store Power

Purpose

If areas are hazardous for humans, the robot will need to store power to allow for safe operation.

Research Findings

We are extremely limited in our options of truly waterproof batteries in terms of specs, size, voltage. It may be beneficial to incorporate in full waterproofing of the robot but will result in larger risk factors to mitigate the risk.

Lithium-Air Battery

  • Rechargeable
  • High energy density

Alkaline Battery

  • Non-rechargeable
  • Various cell arrangement options depending on power needs
  • Requires safety plans in place to reduce risk of electrocution and power shortage

Lithium-Ion Battery

  • Dense and will tend to sink
  • Many RC boat batteries are LiPo which is basically the same as lithium-ion

Metrics

  • Charging time less than 10 hrs
  • Battery lifespan more than 1 day
  • Maximum operational time less than 30 min

Constraints

  • Minimum power output (voltage, current) 16 V
  • Minimum operational time more than 10 min
  • Chemical or physical stability: does not corrode underwater
  • Waterproof
  • Dimensions: no larger than 1/3 size of robot
  • Weight: no more than 5 lbs

Relevant Codes and Standards

(International Battery Standards)

IEC 60086-2, BS

Batteries – General

IEC 61508

The IEC requirements for the functional safety of Electrical/Electronic/Programmable Electronic Safety Related Systems

ANSI C18.2M 

Safety Requirements for Portable Rechargeable Cells and Batteries

Citations

  1. International Battery Standards. Electropaedia, Energy Sources and Storage and History of Technology. (n.d.). Retrieved October 13, 2021, from https://www.mpoweruk.com/.
  2. Imanishi, N., & Yamamoto, O. (2019, November 27). Perspectives and challenges of rechargeable lithium–Air Batteries. Materials Today Advances. Retrieved October 13, 2021, from https://www.sciencedirect.com/science/article/pii/S2590049819301055.
  3. Lithium-ion batteries in water – effect with water. E. (n.d.). Retrieved October 13, 2021, from https://m.greenway-battery.com/news/Lithium-ion-Batteries-in-Water—Effect-with-Water-265.html.
  4. Submersible battery packs. SeaBird. Retrieved October 13, 2021, from https://www.seabird.com/submersible-battery-packs/product-downloads?id=60762467735.