Benchmarking Battery Packs

When benchmarking battery packs the intention is to create a standard list of data and then a list of references. This form will post will form the standard list that we will use going forward and hence we need to get this 90% complete before we start.

The first thing to look at when benchmarking battery packs are the high level specifications:

  • total energy [Wh]
  • usable energy [Wh]
  • peak power [W]
  • continuous power [W]
  • nominal voltage [V]
  • capacity [Ah]
  • voltage range [V]
  • weight [kg]
  • volume [litres]
  • pack dimensions x,y,z [m]
  • number of cells [#]
  • charge time [minutes]
  • cell format
  • cooling system
  • cell make and model
  • pack cost

Using these we can ascertain a number of the key pack metrics:

  • Wh/kg
  • Wh/litre
  • W/kg
  • W/litre
  • $/kWh
  • Cell to Pack mass ratio
  • Cell to Pack volume ratio

Also, these specifications and metrics can be cross-correlated to check their legitimacy.

Other key features:

  • Safety
  • BMS design
  • HV and LV Connections
  • Cooling Connections
  • Structural / non-structural pack
  • Case material
  • Sealing strategy
  • Venting strategy
  • Durability – % of pack capacity available after 10 years
  • Availability
  • Recycling
  • Shipping

This list will need to work with the simplest of battery pack designs through to the most complex.

References:

  • Manufacturer specification pages
  • Manufacturers repair manuals
  • Blogs and articles
  • Youtube teardowns
  • Published usage data
  • Battery consultant teardowns – often programs that have a subscription or substantial report cost.

The battery pack database is now available as an excel file via a download. This is $25 and gives high level data for a number of battery packs (see page for details).

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