SJRV BC50L power use over 24 hours – and what a 100 Ah or 200 Ah lithium battery can handle

The SJRV BC50L is a compact 12 V and 24 V compressor fridge-freezer built for vans, campers and canopies. Running draw is about 60 W. At 12 V that’s roughly 5 A while the compressor is on. Because the compressor cycles, daily use depends on duty cycle and weather rather than a constant 60 W all day.

Typical 24 hour consumption

Real-world figures vary with ambient temperature, ventilation, how often you open the door, and how full the fridge is. Use these as a practical guide.

• Cool day, shaded, minimal door openings – duty around 30% – roughly 5 A × 24 h × 0.30 ≈ 36 Ah per day
• Average Aussie day, normal use – duty around 40% to 50% – roughly 48 to 60 Ah per day
• Hot day or frequent door openings – duty around 60% – roughly 72 Ah per day

What that means for your battery

100 Ah lithium battery

• If the fridge uses about 36 to 50 Ah per day, a 100 Ah LiFePO4 will drop to roughly 50% to 64% state of charge after 24 hours
• On a hot day at around 60 to 72 Ah, you will be closer to 28% to 40% remaining after 24 hours
• You can get through a day comfortably, maybe two if conditions are kind and other loads are minimal, but you will want recharge coming in

200 Ah lithium battery

• The same 36 to 50 Ah per day only uses about 18% to 25% of a 200 Ah bank in 24 hours
• Even in hotter conditions around 60 to 72 Ah, you are using roughly 30% to 36% per day
• Plenty of buffer for lights, fans and charging devices, and far more tolerance for heat and frequent door use

Example day – simple numbers

Warm day around 30 °C, fridge at 4 °C, freezer down to about −18 °C, a handful of door openings across the day. Assume a 45% duty cycle.

• Current while running ≈ 5 A
• Daily use ≈ 5 A × 24 h × 0.45 ≈ 54 Ah per day
• 100 Ah battery after 24 h ≈ 46% remaining
• 200 Ah battery after 24 h ≈ 73% remaining

Tips to keep usage down

• Pre-cool on mains before you head off
• Give the cabinet good ventilation so the compressor can breathe
• Keep it reasonably full so it holds temperature better
• Set sensible temperatures rather than running it unnecessarily cold
• Limit door openings during the heat of the day

Quick solar note

If you plan to stay off-grid for several days, a modest solar setup helps a lot. As a rule of thumb, 200 W to 300 W of panels can replace roughly 60 to 100 Ah on a good sunny day, which is enough to cover the fridge and a few essentials most of the time.

Bottom line

• Expect roughly 30 to 60 Ah per 24 hours in typical use, higher in hot conditions
• A 100 Ah lithium will handle a day comfortably and two days if you are careful and conditions are kind
• A 200 Ah lithium gives you an easy multi-day buffer without stress, especially if paired with 200 W to 300 W of solar

With a secondary battery setup and/or solar charging you'll have no problems running this fridge constantly without power issues.

Back to the 50 litre SJRV 12 Volt Camping Fridge