Off Grid Solar Generator - Part 2: Battery Packs

Starting from the ground up, I decided to build the battery packs first.  Needing to split up the weight so that the system will remain man portable, the batteries were split into two series wired 12V packs.  I also took this opportunity to upgrade the wire size, add fuse protection, and seal the batteries to make it possible later to add hydrogen ventilation.

To begin, the framework was divided into two smaller frames that fit tighter around the batteries.

Then trays were cut to support the batteries using aluminum sheet.  Holes were cut into the sheets and then dimple die'd to add rigidity.

 A 200 amp Class T fuse was added to each pack for short-circuit protection and mounted in an accessible location.

Installation instructions for the PROsine inverter recommend 250 MCM battery cables for runs under 6ft.  Two battery packs means two wire runs, so wire size can be reduced significantly.  Looking at ampacity guidelines, two runs of 1/0 cable has an ampacity 20% greater than a single run of 250 MCM cable.  Wanting to achieve good crimps, I made a test crimp with a new homemade tool,then cut the cable lug in half.  The results were good, the copper was solid and tight within the connector.

The 1/0 cable was cut to length, then lugs were crimped on and finished with heat shrink tubing.

Here is the pack wired up and terminated with an Anderson SB175 connector.

To finish each pack, plastic panels were cut to (semi) seal up each box.

Up next: Part 3: The inverter/charger module