Is that what other folk use? I reckon it sounds pretty light. I would usually use a minimum of 35mm2 for battery connections. 13.5mm2 might *just* suffice if the batteries are sitting next to each other, but even then could become a charging ‘bottleneck’. Telstra also used 35mm2 when they installed the dual battery system my car came with. (Since removed).
The ebay hydraulic crimpers usually come with a variety of dies, the one I have goes from 6mm up to 70mm, & I usually use the one below the size wire I’m crimping. Cost is less than the lever one linked to in the OP. Have had mine for several years now, did all the cables (up to 70mm2) in the Patrol & it’s a reliable piece of gear.
http://www.ebay.com.au/itm/8-Ton-Hyd...item1a0494b8e5 Prices have come down since I bought mine - same as in the ebay link, but I paid around $70.