I don't think the trouble of scavenging, testing and grouping the laptop batteries is worth it. The cheapest quality cells I've found costs around 210 euro for

I don't think the trouble of scavenging, testing and grouping the laptop batteries is worth it. The cheapest quality cells I've found costs around 210 euro for 1 kwh. To reach the same capacity you would need ~17 healthy laptop batteries @ 60wh. With all the added work, buying just one type of cell seems way better. But really, why not buy deep cycle lead acids and an auto-watering system? No hype!