LightShip 4 Now Starting Customer Evaluation

[Holdmybeer]

Yes this feels right! We also know some customers are investigating auxiliary ground deploy systems that would boost the Lightship through the NACS while boondocking, further supplementing roof solar.

Having the power for an extended stay is one thing. Tank capacity is another. My guess is you've got plenty of Batt and Solar onboard for no longer than the black/ gray tanks and fresh water supply are going to allow you to stay in place. Especially with a crew of four. I guess a person could carry extra water and a 30 gal. or so portable waste tank ( which however full would weigh about 250 lbs.).

 

[Rory (Lightship Team)]

Having the power for an extended stay is one thing. Tank capacity is another. My guess is you've got plenty of Batt and Solar onboard for no longer than the black/ gray tanks and fresh water supply are going to allow you to stay in place. Especially with a crew of four. I guess a person could carry extra water and a 30 gal. or so portable waste tank ( which however full would weigh about 250 lbs.).

agree, we believe that water is the primary limiter, though we've maxed that as much as we could (50 fresh, 10 fresh in hot water heater=60 vs the 39 gallons in airstream tradewind 27fb for example)

 

[josephpRV]

agree, we believe that water is the primary limiter, though we've maxed that as much as we could (50 fresh, 10 fresh in hot water heater=60 vs the 39 gallons in airstream tradewind 27fb for example)

+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.

 

[Holdmybeer]

+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.

Gemini says it should be net neutral with the 20k btu hvac in full summer and the solar producing at max capacity, but that's not accounting for any other draws. It will be interesting to see how that bears out. Apparently unlike traditional rooftop units the HVAC on the Lightship isn't either hauling a...or off, but goes into an efficiency/maintainance mode requiring less energy.

 

[josephpRV]

Gemini says it should be net neutral with the 20k btu hvac in full summer and the solar producing at max capacity, but that's not accounting for any other draws. It will be interesting to see how that bears out. Apparently unlike traditional rooftop units the HVAC on the Lightship isn't either hauling a...or off, but goes into an efficiency/maintainance mode requiring less energy.

Yes ... @Rory (Lightship Team) says I'm way overestimating power drawdowns, I'm sure he's right. For transparency here's my assumptions (to be verified when I get VIN 15):

 

[turbopilot]

If you pull in near 100%, as @turbopilot seems to be doing, water may be the only real constraint in typical conditions.

Not sure what all this pre-occupation with water is all about. Water is probably the easiest consumable to source when you are off the grid.

I carry a 30 gallon water bladder in the RV. Folded up it takes up little space when not in use. I also carry a small pump that is driven by an electric hand drill. When I need more water I can normally find some then fill up the bladder in the back of the truck, bring it back to the RV then pump it into the RV.

https://www.amazon.com/dp/B009MU64Y0?tag=rvf01-20

Gray water is next, which for most campers is simply shower water. Shower water is not a hazard. Many who boondock take outside showers by the side their RV. In a remote area there is no reason gray water cannot be used to water the vegetation.

Now we are down to black tank. I have found with careful attention to your "flushing habits" the black water tank can be conserved for a long time.

So I would submit the black tank may be the real limiting factor for extended off grid stays, since there are fewer options to dispose of that waste, versus gray water or sourcing fresh water.

There is an option for the black tank that only the LightShip is configured to support: electric incinerating toilets. I have suggested LightShip put that feature on the new options road map. An electric incinerating toilet does away with the entire black tank. These toilets incinerate solid waste and vaporize liquid waste. It takes about 1.5 kW for a "flush". But some toilets have enough capacity to handle a day or so of cummulative waste before initiating the "flush". These toilets cost between $4k and $6k and run off the 240 volt circuit (NEMA 14-50). I think they could also be engineered to recoup the residue heat generated to offset the kW draw of the hot water tank.

Because of the large battery in the LightShip it is a perfect RV to be the first to eliminate the black tank. They would require extra engineering to satisfy the ventilation requirements for incineration because of the moveable canopy.

 

[turbopilot]

I completed a 300 mile trip to day in Arizona towing the LightShip 4. For this trip I used the LightShip battery only with the air conditioner running while in motion. For this leg I did not hook up the NACS port to the Powerboost, I just ran on battery alone. The solar panels were active satisfying all 12 volt demand while taking the 12 Renogy battery up to 100% SOC.

I departed with the high voltage battery at 93% SOC and arrived at 84% SOC, so I consumed about 7 kW on the trip over the 300 mile trip, mostly supporting the HVAC unit that was set at 73F. I was seeing nominal demand around 600 to 900 watts. Outside temperatures were in the mid 70's during most of the trip.

On a 100 mile segment beginning and ending at sea level, with light winds and a speed target of 62 MPH the fuel economy was 16.7 MPG. I never used TrekDrive on this trip.

The LightShip tows very well. Compared to the Airstream it feels like you always have a strong wind at your back. When I let off the accelerator there is no sudden deceleration like a feel with the Airstream because of all the wind resistance pushing on the Airstream

I also feel much more comfortable towing at higher speeds with the LightShip. With the Airstream I felt uncomfortable going more then 62 MPH. Today with the LightShip I found my cruise speeds feeling natural up to around 70 MPH.

And the heads were turning at the gas stations. It is interesting to watch people when they first see the LightShip. I think many people are trying to process what the machine is at first glance.

 

[Neal]

Does LS have a web portal that allows you to monitor the electricals like Victron's VRM? Also something LS could use to collect data if customers allowed?