Compact solar mesh repeater for exposed locations: kit built around the Inhero MR2 with a 1 W panel in vertical south-facing mounting, two 26700 cylindrical cells, an N bulkhead jack for the antenna connection and a clamp for mounting on 30 mm masts. The enclosure is self-printed (STL files free in the shop).
📖 Build guide: Hilltop Mesh Repeater S – the complete build step by step, including MR2 configuration and the Na-ion pack without BMS
Design principle
An autonomous solar system is dimensioned for the leanest month of the year, not for annual yield. In Central Europe that month is January. The panel therefore sits vertical and facing exactly south: the low winter sun hits it at a favorable angle, snow slides off, and bird droppings and dirt barely stick to the vertical surface. The lower summer yield compared with tilted mounting is irrelevant for autonomy, because summer is never the bottleneck. As a rule of thumb, a vertical, unshaded south-facing panel delivers about 1 Wh per day per Wp in January. The MR2 draws a measured ~1 Wh per day. The balance is tight – and calculated to be exactly that.
Energy budget
During overcast spells the setup runs at a deficit. That is part of the design: the two 26700 cells buffer at least 25 days of operation without meaningful solar yield. Through dark weeks, battery capacity helps – panel wattage does not, since a larger panel delivers just as little under overcast skies and snow. This tight dimensioning is only possible because of the MR2: ~1 Wh daily consumption, MPPT charge controller, and automatic deep sleep with self-recovery once the sun has recharged the battery.
Enclosure size
The enclosure is drawn for minimal wind load and low visibility. 5 to 20 W of solar area are common in the community; such builds present a large wind attack surface at exposed sites and are visible from afar. This enclosure can be mounted where larger builds are ruled out mechanically or visually.
Site requirements
An unshaded, exposed location (hilltop, roof, mast) and exact south orientation are mandatory. The tightly dimensioned panel depends on every hour of sun. For partially shaded sites or sites without ideal south orientation, the Hilltop Mesh Repeater L is the intended choice.
Included in the kit
- 1 × MR2 solar mesh repeater board (multi-chemistry, MPPT, RED/CE-certified)
- 1 × battery cable – choose variant: with LiFePO4 or Li-Ion protection module, or without BMS (open ends – for LTO and Na-Ion builds)
- 1 × BLE adhesive antenna 2.4 GHz (configuration and OTA updates via app)
- 1 × pigtail N bulkhead jack → U.FL, 15 cm
- 1 × ZIISOR 868 MHz fiberglass antenna with N-male connector – choose variant: 3 dBi (26 cm), 5.5 dBi (40 cm) or 8 dBi (55 cm). Not included with the “no antenna” variant.
- 1 × solar panel 6 V / 1 W with pre-soldered cable
- 1 × screw set for MR2 mounting (stainless steel A2)
- 1 × stainless steel bolt set for mast mounting (3 × M6×50 mm TX30, 3 × M6 nuts) – the nuts sit captive in the hex pockets, so no wrench is needed
Also required
- 2 × 26700 cylindrical cells – LiFePO4 or Li-Ion, matching the chosen battery cable variant. The without-BMS variant is intended for LTO (2S, external balancer required) and Na-Ion cells – details in the battery chemistry guide
- Only with the “no antenna” variant: an omni antenna with N-male connector. Please note: the enclosure’s antenna base seal is dimensioned for the base diameter of the ZIISOR fiberglass antennas; all three ZIISOR models share the same base diameter. Antennas with a different base cannot be sealed properly with the supplied part.
- 3D printer; weather- and UV-resistant filament – ASA-CF is very well suited
- Adhesive/sealant and adhesive-lined heat-shrink tubing for the antenna base seal
Construction & mounting
- Designed for 2 × 26700 cylindrical cells and an N bulkhead jack (antenna connection)
- Mast mounting: clamp for a 30 mm mast – the required bolts and nuts are included as a stainless steel set
- Sealing: after antenna installation, the antenna base seal is glued to the enclosure and the transition to the antenna sealed with adhesive-lined heat-shrink tubing
📖 Further reading: battery chemistry guide with capacity planning in the MR2 documentation
Manufacturer Information (GPSR)
Inhero GmbH, Gewerbestraße 19, 08115 Lichtentanne, Germany · info@inhero.de