In Part 1, I explained how clean technology made camping a lot better (and safer) for my brother. I then got into the challenges that come when you park an RV somewhere other than an RV park, and you can’t plug it in. Now, I’m going to discuss the ways that cleantech is solving it.
The Challenges of Boondocking are Driving Crazy Efficiency for Refrigeration & HVAC
Better efficiency and better battery technology is slowly changing the equation on battery power for RVs.
LED bulbs mean kids can keep the lights on pretty much as much as they want now, even with lead-acid batteries. Lithium batteries not only have more capacity in the same size, but you can run them down almost dead without doing big damage to their guts. So, in the space of a lead-acid battery, you can double or quadruple the amount of power on tap.
If you don’t mind giving up a little bit of storage space, you can put a bank of several lithium battery packs to increase energy storage. In my case, I’ve got a bank of four lithium deep-cycle batteries that I’m about to review for Lion Energy. With all four batteries wired together, that gives me around 420 amp-hours, or a little over 5 kWh of storage at 14 volts (the normal voltage for lithium batteries, the number could be a lot higher). That’s not impressive by Tesla Powerwall standards, but for an RV, that’s a lot of juice!
But a traditional RV air conditioner pulls anywhere from 1000-5000 watts. That would deplete the battery bank in only an hour at worst, and 5 hours at best. On a hot night, you’d wake up at 3 AM when the AC quit and the place gets hot. A typical RV refrigerator could pull only a trickle of power if you’re running it on propane, but putting that on electricity would mean another 1000 watts, cutting the best-case for a traditional AC in half, leaving you sweating it out after only 2-3 hours.
However, companies are solving all of that, both for RVers and for truckers. There are air conditioners like the Dometic RTX 2000 or the Mabru RV 12000 that run on 12 volts (eliminating power inverter losses) and pull less than 300 watts in “eco” mode. Testing shows that for a smaller RV or truck sleeper, these units do just fine, and don’t even pull that 300 watts continuously when it’s cooler (but still uncomfortable) at night. That means with my battery bank, I’d be looking at over 16 hours of runtime keeping the RV cool. If I found a model with a heat pump, I could keep the RV warm, too.
As we learned from my brother’s story, refrigerating food with a 12-volt ice box (which can be built-in instead of looking like an ice chest) means you’d only need another 50 watts or so, which barely puts a dent in the air conditioning time. With 800-1200 watts of solar on the roof and a DC-DC charger that can top the battery bank off from the RV’s engine on cloudy days, going to bed with more than enough battery to sleep comfortably isn’t a problem.
This doesn’t completely solve the challenges of cooking or having hot water for a shower, but we can use a little bit of propane for those things until the technology for those improves a little more, too.
There’s no reason these super efficient technologies can’t be transplanted and scaled up a bit for stationary homes, businesses, and other uses. There isn’t that much demand for it, but keeping energy consumption down helps keep the need for grid power or rooftop solar and battery storage down instead of up. So, the challenges of boondocking and RVing could pay off for everyone in the next few years!
Featured image by my brother (used with permission).