A compressor fridge is the single biggest power user on most South African camping trips, so the useful question isn't just "how many litres?" but "how much battery will it need?". The table sets out five portable 12V fridge/freezers in the 40 to 52 litre range, using the figures their makers publish.
We haven't used, measured or tested any of these fridges. Every number comes from the manufacturer's own page or manual (linked on each row), checked on 15 October 2026. Makers don't publish power use the same way. One gives amp-hours per hour at a stated temperature, others give a rated current or a wattage range, so the power column can't be read as a straight ranking. The section below explains why.
The table
| Model | Capacity (L) | Weight (kg) | External size (mm) | DC supply | Published power figure | Temperature setting (°C) | Warranty | Source |
|---|---|---|---|---|---|---|---|---|
| NL 52 Legacy SmartNational Luna | 52.6 | 24.4 | 710 × 385 × 506 closed, including handles, latches and hinges | 9.6–32 V | Running power 40–75 W, no USB loads (from the Legacy Smart manual, which covers the whole range) | Down to -30 (minimum setting) | 3 years | nationalluna.com |
| CFX5 45Dometic | 46 | 18.26 | 398 W × 694 D × 476 H (rounded from 398.02 × 693.93 × 476) | 12/24 V | 0.76 Ah/h at 12 V (32 °C outside, 4 °C inside); rated input 9.4 A at 12 V | +20 to -22 | 3 years | dometic.com |
| SMDZ-TR42S (42 L, stainless steel)SnoMaster | 42 | 23.5 | 365 W × 680 D × 520 H, including handles and hinges | 12/24 V | Compressor 45 W; rated current 3.75 A at 12 V | +10 to -22 | not published | snomaster.co.za |
| SMLS-50 (40 L, plastic)SnoMaster | 40 | 13 | 657 W × 401 D × 394 H, including handles and hinges | 12/24 V (220 V via an external adapter) | Total input power 60 W; rated current 5.9 A at 12 V | +20 to -20 | not published | snomaster.co.za |
| MT-V45F 40 L (Engel Australia listing)Engel | 40 | 24 | 631 W × 360 D × 508 H, plus 60 mm per handle | 12/24 V (also 240 V AC) | DC consumption variable from 0.5 to 3.0 A | not published | 5 years (Engel Australia terms; South African terms may differ) | engelaustralia.com.au |
- National Luna NL 52 Legacy Smart: Single compartment, stainless steel exterior, lid can be set to open from the front or the side.
- Dometic CFX5 45: Capacity is stated to IEC 62552-3; Dometic lists an operating ambient range of 16 °C to 43 °C.
- SnoMaster SMDZ-TR42S (42 L, stainless steel): SnoMaster lists 50 mm polyurethane insulation and asks for 150 mm clearance around the unit for airflow.
- SnoMaster SMLS-50 (40 L, plastic): Low-voltage cut-out can be set to 10 V, 10.7 V or 11.8 V; SnoMaster says not to tilt it more than 45°.
- Engel MT-V45F 40 L (Engel Australia listing): Figures are from Engel's Australian distributor; we couldn't find a South African Engel page with a spec table, so check the rating plate on local stock.
Reading the table
Capacity and outside size
Litres tell you how much fits inside; the outside size tells you whether it fits your load bay, fridge slide or canopy. These are not the same thing: insulation thickness and the compressor housing add a lot. Measure the space you have, including room to open the lid and the ventilation gap the maker asks for (SnoMaster says 150 mm). If the fridge will sit on a slide, check the slide's size and load rating too.
Why the power figures don't line up
Each maker reports power differently:
- Amp-hours per hour (Ah/h) at a stated outside and inside temperature (Dometic: 0.76 Ah/h at 32 °C outside, 4 °C inside) is the most useful number for planning, because it already averages the compressor switching on and off.
- Rated current (SnoMaster: 3.75 A or 5.9 A at 12 V; Dometic: 9.4 A) is roughly what the fridge draws while the compressor is running. It doesn't run all the time, so daily use is lower.
- Watts (National Luna: 40 to 75 W running) can be turned into amps at 12 V by dividing by 12, so 60 W is about 5 A while running.
- A current range (Engel: 0.5 to 3.0 A) shows low and peak draw but not how long it spends at each.
Real daily use depends heavily on outside temperature, how cold you set it, how full it is and how often it's opened. Compare power only where two makers use the same measure.
DC supply range
All five run on 12 V and 24 V. National Luna publishes a working range of 9.6 to 32 V. The more important setting is the low-voltage cut-out, which switches the fridge off before it flattens your battery. SnoMaster lists three cut-out levels on the SMLS-50; National Luna lists low-battery protection without giving the voltages on the product page, and Engel's page doesn't mention it. Set the cut-out to suit your battery type (see the buying guide).
Temperature setting
All five can freeze, and these are single-compartment units, so they work as either a fridge or a freezer at one time, not both. If you want frozen meat and cold drinks together, look at dual-zone models or a second unit. Dometic also lists an ambient operating range (16 °C to 43 °C), which is the outside air temperature the fridge is designed for, not what it can be set to. A hot vehicle or closed canopy in the Kalahari in summer can get close to the top of that.
Warranty
National Luna and Dometic list three years on their South African pages. Engel's five years comes from its Australian distributor and may not apply to local stock. SnoMaster links to a separate warranty page rather than stating the term on these product pages, so we've left it as not published. Always confirm warranty terms with the seller.
Buying guide
Work out your daily power use first
Use the maker's Ah/h figure if they publish one. Dometic's 0.76 Ah/h at 32 °C ambient works out to roughly 18 Ah over 24 hours at those test conditions (our calculation: 0.76 × 24). If the maker only gives watts or a rated current, ask them for an average daily figure at a stated temperature; guessing from the peak current will give you a number that's too high, and guessing from the low end will leave you short. Allow extra for hot weather, a warm fridge being cooled down, and frequent opening.
Size the battery with headroom
National Luna's manual suggests a battery of at least 100 Ah, with 100 to 150 W of solar if 6 to 8 hours of direct sun is available, for remote use where solar is the main charging source. Treat that as a starting point. Lead-acid batteries (flooded or AGM) last longer if you don't drain them deeply, so you can only plan on using part of their capacity; lithium (LiFePO4) batteries tolerate deeper discharge. Check your battery maker's recommended depth of discharge, then size the battery so a full day (or two, if you'll stand still without sun) fits inside it.
Wire it properly
Voltage drop on thin or long cables is a common reason a fridge cuts out on a full battery. National Luna's manual specifies at least 4 mm² cable between the fridge and battery and a 15 A fuse close to the battery on the positive cable. Follow your fridge maker's own cable size and fuse rating, and use a dedicated circuit rather than a shared cigarette-lighter socket where you can. If you're adding a second battery, have a qualified auto electrician fit the isolator or DC-DC charger.
Set the low-voltage cut-out for your battery
If the fridge runs from your starting battery, use the highest cut-out setting so you can still start the vehicle. On a dedicated auxiliary battery, follow the battery maker's guidance: lithium and lead-acid batteries have different safe minimum voltages.
Mounting and ventilation
The NL 52 weighs 24.4 kg empty, and a load of food and drinks adds a lot more, so the fridge must be tied down to rated points or a proper fridge slide. A loose fridge in a crash or hard braking is dangerous. Leave the ventilation gap the maker asks for and keep the vents clear of dust and bags; a fridge that can't get rid of heat runs longer and uses more power.
Plan for how you camp
If you mostly do weekends with a vehicle that gets driven daily, a smaller fridge on a modest battery will cope. If you stand still for days at a time, power budget and solar matter more than an extra 10 litres. A dedicated freezer plus a separate fridge, or a dual-zone unit, may suit long trips better than one large box.