Embedded Electronic Designs
Featured
All prices shown are ex VAT and the product carries a 1-year warranty.
Does your motorhome, caravan or campervan fridge struggle in hot weather?
Fridges work hard in summer — and without proper airflow the fridge becomes inefficient.
FridgeAir fixes that.
It continuously monitors the temperature difference between the top and bottom of the cavity and chimney behind the fridge. When the top starts rising faster than the bottom — a reliable early warning that natural airflow is no longer keeping up — FridgeAir automatically starts circulating air before temperatures climb high enough to affect cooling performance.
Quiet when cool. Powerful when hot. You’ll never think about it again.
No app. No on/off switch. No Bluetooth. No setup. Just plug it in — it works, whatever the season.
Click to see Herman Hits the Road install & review
What FridgeAir does
Smart delta-driven cooling — unlike traditional thermostatic controllers, FridgeAir reacts to temperature difference, not just temperature, if the top of the cavity starts running noticeably hotter than the bottom, FridgeAir brings the bottom fan in to help circulate air, even before the bottom sensor itself has warmed up.
Continuously monitors top and bottom temperatures with precision digital sensors.
Variable fan speed — ramps up with temperature, very quiet when cool.
Protects your leisure battery — fans cut automatically if voltage drops too low for a sustained period, then restart when charging resumes.
Single-sensor mode — works with just one sensor and one fan. FridgeAir automatically switches to a tuned single-fan profile so performance stays strong even when dual-sensor/fan routing isn’t practical.
Green LED heartbeat confirms the unit is alive and working.
Double-flash warning when the leisure battery voltage is marginal — the unit hibernates until the battery recovers.
Boot self-test — both fans run briefly at startup so you know everything is working.
While idle and monitoring, FridgeAir draws only ~65µA (~0.002Ah per day), helping preserve your leisure battery.
PCB protected with MG Chemicals 419D acrylic conformal coating for moisture and vibration resistance.
Clearly labelled — wiring takes minutes
A — 12V DC power input
B — Top sensor
C — Bottom sensor
D — Top fan output
E — Bottom fan output
What’s in the box
Controller only option
FridgeAir controller in carbon-fibre PLA enclosure
2 × DS18B20 temperature sensors
2 × sensor mounting clips
2 × cable ties
Quick Start Guide
Complete kit adds
2 × 12V DC 120×120 mm fans with mounting hardware
2m red/black 18AWG cable
2 × lever-nut splice connectors
Technical
Protected input — onboard self-resetting polyfuse (3.5A hold / 6A trip) and reverse polarity protection safeguard both the unit and your vehicle wiring from wiring faults and transient events.
Supply: 12V DC (leisure battery).
Fan output: 12V PWM, dual channel, variable speed.
Top fan triggers above 45 °C, full speed at 65 °C.
Bottom fan triggers above 40 °C, full speed at 65 °C.
Separate fan profiles optimise airflow direction and minimise unnecessary fan operation.
Smart delta-latch — automatically runs the bottom fan whenever the top sensor is above 36°C and the temperature difference between top and bottom reaches 8°C, ensuring cold-air circulation even before the bottom temperature rises on its own. Once running, it stays engaged until the gap is acceptable.
Leisure battery warning below 12.3V, protection cuts in below 12.0V sustained, auto-recovers above 12.4V.
Flexible fan outputs — each channel can drive two fans in parallel (max 0.6A / 7.2W per channel). Dual fans top and dual fans bottom is fully supported.
Single-sensor mode — plug one sensor into the Bottom sensor terminal and mount that sensor (and the fan(s)) at the top of the chimney. FridgeAir detects this and switches to an enhanced single-fan profile.
Click for the Quick Start Guide
To see Herman Hits the Road install & review, [click here]
For full photo gallery including PCB detail [click here]
"Very pleased with the FridgeAir system now fitted." FridgeAir customer, UK
All prices shown are ex VAT and the product carries a 1 year warranty.
The Founders Edition is our first, limited run of BattGuard. Every unit is hand-built and individually tested here in the UK, and each one looks after a single 12v battery. Only four are available.
Ever come back to your motorhome, caravan, campervan or classic car to find the battery flat?
Batteries don't go flat all at once. They drain quietly while the vehicle sits, and you only find out when nothing works or the engine won't start.
BattGuard fixes that.
It keeps an eye on your 12v battery around the clock and texts your phone in plain English if it starts getting low, telling you the voltage and roughly how long until it's critical. Text it whenever it's online and it tells you how the battery is doing.
Quiet when all is well. Straight to your phone when it isn't.
No app. No account. No Bluetooth. No subscription. Just a text, and a simple setup page on your phone.
What BattGuard does
Texts you when the battery is getting LOW, when it's CRITICAL, when it's FLAT, and again when it's OK, with the voltage and an estimate of the time to the next level.
Alerts go to up to four mobile numbers, so the whole family or your storage site can know.
Works on a leisure battery or a vehicle starter battery, lead-acid (flooded, AGM and gel) or lithium LiFePO4, with wording to suit each. Set the battery type with the Li/Pb switch on the unit or choose it on the setup page.
Slowly draining warning if the battery is losing a little charge every day.
Overcharging alert on a vehicle starter battery. If the alternator pushes the voltage too high, BattGuard texts you that the charging system may be faulty, and again when it's back to normal.
Engine starting won't cause false alarms. BattGuard ignores the short dip while the engine starts.
Checks the alert is real before texting, so a passing load or a single odd reading won't set it off.
Weekly check text every Sunday morning, so you know BattGuard is still on duty. It also keeps the SIM in use.
Text 1234 STATUS for the battery right now, for example: "VAN STATUS 14:05: Vehicle 12.62V, about 94%, Lead-acid, OK, resting."
Optional daily text window. BattGuard stays online at a time you choose and answers straight away.
Uses 4G, so it keeps working after the older 2G and 3G networks are switched off.
Sleeps most of the time to look after your battery.
Set up in minutes
Activate the supplied giffgaff SIM on pay as you go.
Connect red to battery positive and black to battery negative, using the fused lead supplied.
Join the BattGuard Wi-Fi on your phone and fill in the setup page: your numbers, a PIN, the battery type and a name.
Save. A minute or two later you'll get your first text.
Discreet features
Please note. These features are an extra, not a replacement for an approved vehicle tracker. If your insurer asks for an approved tracker, keep using it alongside BattGuard.
Text LOCATE and BattGuard replies with a Google Maps link to its rough area, worked out from nearby phone masts.
Motion alerts if it's moved more than a few hundred metres while it's online.
Text TRACK if the vehicle is stolen, and it texts its rough position every hour until you text HOME.
Text AWAY before a trip so your own journeys aren't reported.
What's in the box
BattGuard Founders Edition unit with red and black battery leads fitted
giffgaff SIM card, already fitted, with its activation code
Conformity test certificate
Quick Start Guide
Technical
Supply: 12v battery, lead-acid or lithium LiFePO4. Not for 24v systems.
Network: 4G texts, using the supplied giffgaff SIM or your own SIM that can send and receive texts.
Protected input: 2A fuse inside the unit. Reverse polarity tested.
Batteries monitored: one.
Built-in leisure lead-acid levels: LOW below 12.4v, CRITICAL below 12.2v, FLAT below 11.9v. Levels can be changed on the setup page.
Alerts are confirmed over several readings before a text goes out.
Location: approximate, from phone masts, with no GPS.
Enclosure: PLA Carbon Fibre (CF).
Sleep current: 30µA.
Designed, hand-built and tested in the UK by Digconn Systems.
All prices shown are ex VAT and the product carries a 1-year warranty.
The original Lotus Esprit headlight pod control module (A082M6363F / GM16523917) is no longer available from Lotus or GM. These units commonly fail from overheating, failed relays, cracked solder joints, unreliable stall detection, crumbling PCBs and classic MOSFET burnout. This is a complete plug-and-play UK-built replacement — a new controller, not a repair of the old board.
Key features
Position memory — remembers pod position even after battery disconnect
Independent motor stall detection
Obstruction safety cutoff
Ultra-low idle current (2.4mA, less than 2Ah per month) — ideal for long-term storage
Conformal coated for protection against moisture, condensation and vibration
Direct drop-in fit — no wiring modifications required
Custom 3D-printed carbon black PLA-CF enclosure
Hand-built and fully tested in the UK by Digconn Systems
Replaces
Lotus part number: A082M6363F
GM part number: GM16523917
Confirmed compatibility
Lotus Esprit (1989–2004)
Renault Alpine A610 (1991–1995)
Also expected to fit (pending confirmation)
Chevrolet Corvette C5 (1997–2004)
Important note
The Lotus Esprit and Renault Alpine A610 are the only vehicles fully tested and confirmed. The Corvette C5 shares GM16523917 and is expected to be compatible, but has not yet been independently verified. If you own a Corvette C5 then please contact us using the contact page before ordering.
Full technical details are available on GitHub: