+1 that water is likely the primary constraint, with power a close second. On the power side, it really comes down to three variables: arrival SOC, daily solar input, and daily output (systems, accessories, HVAC).
I’m continuing to refine my CER calculator (Camp Establishment Reserve), or more practically, “How much power do I need for a 3/5/7-day boondocking trip?”.
While I wait patiently for VIN 15 to roll off the line and begin real-world testing, my primary analytics have focused on:
1. EV tow vehicle range (now largely answered), and
2. CER sustainability once on site.
My current theoretical modeling supports the premise that water, not power, is likely the limiting factor in most scenarios. That said, there are clear baseline and edge cases (especially arrival SOC). If you pull in near 100%, as
@turbopilot seems to be doing, water may be the only real constraint in typical conditions.
Tokenblitzing with ChatGPT to pressure-test my assumptions, the 1.8 kWh solar array appears to average roughly:
- Fall: ~5.0 kWh/day
- Spring: ~5.0 kWh/day
- Summer: ~8.0 kWh/day
- Winter: ~3.0 kWh/day
Against that, modeled kWh (systems and HVAC) draw ranges from ~5.5 kWh/day (≈20° temp delta over 8–10 hrs) up to ~9.5 kWh/day (≈40° delta). I built a sliding-scale model using interpolated data from
@Rory (Lightship Team)’s Florida testing.
In reality there are hundreds of variables (shade, orientation, usage behavior, etc.). But so far the modeling is showing:
- Summer: likely net positive or neutral energy into the battery
- Spring/Fall: neutral to modest drawdown on the battery
- Winter: meaningful battery drawdown
I’ll validate all of this once VIN 15 arrives, but the modeling is increasing my confidence that, in most real-world scenarios, water will tap out before electrons do.
