[francis_t_catte]

For a while I was scrapping dead laptop batteries to build an 18650 pack for my esk8 build. I ended up building a battery validation rig with a Turnigy battery charger that charges the battery to 4.2V, drains it to 3.8V, and charges it back up to 4.2V to figure out its true storage rating. Then I sorted them by manufacturer, model, and storage capacity, with a recycling bin for anything below 80% of their rated capacity, open cells, and shorted cells.

It's a lot of work, but the validation was all automated via the charger. The pack I ended up with had healthy cells all within 10% of each other in terms of capacity.