1.6.2 Battery form factors

Stackable > vertical / wall-mounted > visible-wiring chains.
Stackable installs are simplest but take up more floor area.
Wall-mounted vertical units take less area, but verify it is a current-generation product. Older models still sold in the U.S. squeeze only one-third of the capacity into the same footprint as today's batteries.
Open-wiring chains loosen and can short over time — rarely approved for residential installs in cities.