The "BOM" lists a 35 Ah / 12 V battery, which is reasonable. A 420 Ah battery is (a) a boutique item (b) should weight around 120-140 kg (c) does not fit into a toolbox (d) costs significantly more than 299 $.

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From a professional standpoint I'd nag about

> the battery is laid into the tool tray. Plenty of extra space in this toolbox, which protects the system from dust and the sun.

A closed box is not a good place to keep actively cooled electronics; less so when it's a black box in the sun.