Heltec T114 solar and air cooled case with 10,000mAh battery - Immortal

A solar powered Heltec T114 with active air cooling and a 10,000mAh battery. The fan will activate automatically when the case heats to 40℃ and turn off when cool. Named 'Immortal' because it can go months on a single full charge. This case can also accommodate an L76K GPS module. No screws or bolts required. Print in light coloured PETG (dark colours absorb heat, PLA filament will break on the side clips that keep the case together).

This build is not affiliated with or endorsed by Heltec. It's my own design and the logo is just decoration.

Parts list for the full build:

• Heltec T114

• 10,000mAh 3.7V LiPo battery

• 130mm x 60mm solar panel (listed as 5V 200mA)

• KSD9700 Thermostat, 40℃ Normally Open Temperature Switch 5A (Other switches should work. You may want a switch that works at higher temps)

• Caizhu CZ 2006g 20mm x 20mm x 6mm fan (these fans are 'blower' types so they exhaust out the side)

• L76K GPS module (optional)

• Probably a Micro JST 1.25SH Female to JST-PH 2.0 Male adapter cable for the battery connection. CHECK POLARITY BEFORE POWERING THE T114! Sometimes these connectors or batteries are incorrectly wired for the Heltec, test them with a multimeter. You may need to pull the cable crimps from the plastic connectors and switch them around, the print on the T114 board by the JST connectors shows which side is + and -.

Cooling system:

The fan connects to the thermostat, the thermostat connects to the battery. This cooling system has a very low power usage so the battery will still charge from solar while the fan is running. The rear exhaust vent is curved to prevent back pressure so the fan runs very quietly. There are vent holes around the bottom of the case to draw in cool air behind the solar panel and around the battery.

Printed parts assembly:

'Immortal Case Top' - See images. The 'Immortal Case Button' fits into the recess for the User button of the T114. The T114 pushes into the front frame (push the USB side in first). The fan pushes into the rear centre with the exhaust pointing up towards the vent. GPS module pushes into the recess next to the fan. Fit IPEX SMA pigtail for the antenna in the top.

'Immortal Case Bottom' - There are 2 different internal sized parts available depending on the width of battery you use (batteries are usually either 60mm or 63mm wide). Battery drops into the large slot. Solar panel slides into front rails, there is a centre gap so the cables will not be trapped. Thermostat sits in either side gap between the battery and solar panel. Any loose cables can also fit in the gaps.

'Antenna Connector Ring' - Hides the external SMA connector under the antenna. This is optional, it just makes it look better.

'Immortal Case Button' - For the 'User' button of the T114. There is no button for the 'Reset', use something pointy.

'Heltec Badge' - Single piece badge. This can be glued to the front of the case.*

'Heltec Badge With Cutout' - Two piece badge so you can customise the background text colour/texture. Requires the 'Heltec Badge Cutout Infill', this is a small rectangle that fits inside the back of the badge behind the text. Glue together.*

'Immortal Tilt Stand' - A stand for the case that helps point the solar panel higher. Useful for solar charging on a window sill.

• This build is not affiliated with or endorsed by Heltec in any way. It's my own design and the logo is just decoration.