PokupkaPro & Silvera
PokupkaPro
I’ve just dissected the newest graphene‑based solid‑state batteries—any idea if they could seriously extend drone endurance for a lunar outpost?
Silvera
Solid‑state graphene cells can seriously boost drone endurance—think 40‑50% more flight time on the Moon if we keep the heat in check. I sketched a lightweight thermal buffer that could do the trick. Want to run a quick prototype test before the next funding deck?
PokupkaPro
Sure, let’s get the specs on that buffer—material, mass, thermal conductivity, weight per square meter. And we need a detailed heat‑flux model for lunar regolith exposure, otherwise you’ll end up with a nice looking prototype that just overcooks the cells. Also bring the battery’s voltage‑current curve and capacity fade data; we’ll run a full simulation before you touch anything.
Silvera
Okay, here’s the quick rundown: the buffer is a composite of aerogel‑reinforced polymer—about 0.6 mm thick, mass 0.12 kg per square meter, thermal conductivity 0.04 W/m·K, so we’re looking at roughly 0.1 kg/m² in total. For the lunar regolith heat‑flux model I’ve got a 3‑D finite‑difference setup that runs the regolith temperature, solar radiation, and conduction through the buffer over a 24‑hour cycle—keeps the cells below 50 °C even at peak sun. Battery data: nominal voltage 4.2 V, max 5.5 V under load, 250 mAh capacity, 5 % fade per 100 cycles, and the I‑V curve shows a flat plateau until 80 % SOC. We’ll plug everything into the simulation and see if the buffer holds up before we actually build anything. Let's keep the coffee flowing, and we’ll get this in the deck before the next IPO round.
PokupkaPro
That’s a solid starting point, but you’re still skirting the edge of thermal runaway if the regolith temperature spikes in a micrometeorite event; add a safety margin to the conductivity figure and run a worst‑case scenario. Also the 250 mAh figure is tiny for a lunar drone—unless you’re planning a 30‑second hover, you’ll need to stack cells or rethink the power budget. Run the simulation with a 10‑minute spike at 70 % irradiance and see how the 5 % fade stacks up over 300 cycles; that’s the minimum you need to convince the board. Coffee is fine, but let’s keep the data as clean as the design.
Silvera
Got it, tightening the safety net. I bumped the thermal conductivity up to 0.06 W/m·K and added a 20 % margin in the model. Ran the worst‑case 10‑minute, 70 % irradiance spike—cells stayed under 55 °C, so no runaway risk. For the 300‑cycle fade, the 5 % per 100 cycles stacks to about 15 % overall, which is still within our tolerance if we go with a 6‑cell stack for a 1.5 Ah pack. The power budget now matches a 10‑minute hover with a little wiggle room for transit. I’ve got the updated heat‑flux plot and battery curve ready for the deck; the board should see a clean, risk‑managed pitch. Let's keep the coffee coming, but the data is solid.
PokupkaPro
Nice work tightening the margin, but remember that a 6‑cell stack still adds roughly 0.7 kg plus the buffer weight—keep the total mass in line with the launch budget. Also, the flat I‑V plateau means you’ll draw a high current during the recharge phase; verify the charger can handle that without overheating. If that checks out, the deck should look solid. Keep the coffee flowing, but keep the data tight.
Silvera
Mass is creeping—6 cells and the buffer hit 1.4 kg, so I’m slashing the buffer to 0.4 mm and swapping the aerogel for a carbon‑foam blend; that cuts another 0.2 kg and pushes conductivity to 0.07 W/m·K. The charger’s got a 2 A ramp‑up spec and a passive heat sink, so it stays below 65 °C under peak recharge. All the numbers are in the deck, and the coffee is brewing—ready to pitch without breaking the launch budget.