Chevy Malibu OEM 16s 57.6v battery module
Here are EV battery modules that came out of Chevy Malibu eco hybrid vehicles. This is a true, high power, low density battery module. Each module is used to push 5.5kW of power and 7.5kW of regenerative charge. These are the 3rd gen Hitachi 40mmx92mm 4.4ah cells with 3000 w/kg power density. Each cell weight is 0.26kg so that means each cell can push up to 49c (216a). That is almost a 50c rating. I would consider that a peak, pulse, or 10 second rating. Max continuous is likely around 90 amps per cell but that information is not available. These would be a great candidate for a car audio application but always make sure you do your testing when making a high amp battery for applications like that. Of course these are used batteries so you should expect a little degradation but every cell has been checked for voltage and all cells are balanced. Just $5 per cell at this price for the module.
Module weight is 13.5 lbs.