- This topic has 6 replies, 4 voices, and was last updated 7 years, 3 months ago by
.
- Posts
Hi, I have a camping gaz fridge installed in my van. Given that it draws 9A would it be possible to run it from a leisure battery and what size solar panel would I need to keep it going with enough charge to get it through the night ?.
Hi
Hi9A is quite a lot, but you could run this fridge of a single 110AH leisure battery, connected with a 100W solar panel.
If you want to run more from this setup, you could think about adding another battery.
I would always recommend using a split charge replay to charge the leisure battery from the engine when it is running.
These are quite cheap.Hi
Hi9A is quite a lot, but you could run this fridge of a single 110AH leisure battery, connected with a 100W solar panel.
If you want to run more from this setup, you could think about adding another battery.
I would always recommend using a split charge replay to charge the leisure battery from the engine when it is running.
These are quite cheap.Absorption fridges are just
Absorption fridges are just not suitable for 12V use other than when the engine is running.
For example the actual useful capacity of a 120Ah battery is really only about 40Ah, which only will last 5 hours.
I say useful capacity, because you really should not run the battery below 50% and typically it will only charge to 85%.Really you need a compressor fridge which will draw ~3A when running, but will cut in and out and average maybe 1A per hour. This would then let you run for 40 hours without topping up.
A 100W solar panel – in theory will get you ~7A in full sun, however real use will be a lot less. Typically at the moment I’m seeing 2A, but I would expect this to increase towards the summer & further south. In my case I’m supplementing the solar with as split charge relay – and an onboard CTEK battery charger when I’m on hookup. With the split charge relay I’m seeing about 8-10A, so a 2 – 3 drive would be enough to keep the fridge topped up for the day.
Absorption fridges are just
Absorption fridges are just not suitable for 12V use other than when the engine is running.
For example the actual useful capacity of a 120Ah battery is really only about 40Ah, which only will last 5 hours.
I say useful capacity, because you really should not run the battery below 50% and typically it will only charge to 85%.Really you need a compressor fridge which will draw ~3A when running, but will cut in and out and average maybe 1A per hour. This would then let you run for 40 hours without topping up.
A 100W solar panel – in theory will get you ~7A in full sun, however real use will be a lot less. Typically at the moment I’m seeing 2A, but I would expect this to increase towards the summer & further south. In my case I’m supplementing the solar with as split charge relay – and an onboard CTEK battery charger when I’m on hookup. With the split charge relay I’m seeing about 8-10A, so a 2 – 3 drive would be enough to keep the fridge topped up for the day.
Solar Panels / Absorption Fridges
Hi – might be a bit late on this – the following sums may assist:-Power in Watts(W) = current in Amps (A) x Voltage in Volts (V)
Energy in Watt hours (Wh) = power in Watts (W) x time in hours(h)
Battery capacity in Amp hours (Ah) = energy in Watt hours / Voltage in Volts (V)Your wattage = 9*12V = 108W. Thats a big call for a campervan
If your leisure battery is 110Ah then if fully charged it should last for 12.2hours (110/12). However I would get a local garage to test your battery, many leisure batteries say they are 110 given this is an industry size but they may skimp on the lead content and have a lower output – you might want to think about 2×110 batteries with a split charger if your going to run the fridge off your batteries.
Although the fridge may say 9A – that’s the max it will use if its in defrost mode or your constantly going in and out of it, so the average consumption will be lower than this.
Even so to produce 9A for one hour you’ll need at least 100W and given inefficiencies and not direct sunshine then you’ll be looking the biggest you can get say 150W.
Unfortunately absorption fridges are very hungry on power, whereas the compressor type are less so. I hope you manage to find a solution.
Hope this helps
Solar Panels / Absorption Fridges
Hi – might be a bit late on this – the following sums may assist:-Power in Watts(W) = current in Amps (A) x Voltage in Volts (V)
Energy in Watt hours (Wh) = power in Watts (W) x time in hours(h)
Battery capacity in Amp hours (Ah) = energy in Watt hours / Voltage in Volts (V)Your wattage = 9*12V = 108W. Thats a big call for a campervan
If your leisure battery is 110Ah then if fully charged it should last for 12.2hours (110/12). However I would get a local garage to test your battery, many leisure batteries say they are 110 given this is an industry size but they may skimp on the lead content and have a lower output – you might want to think about 2×110 batteries with a split charger if your going to run the fridge off your batteries.
Although the fridge may say 9A – that’s the max it will use if its in defrost mode or your constantly going in and out of it, so the average consumption will be lower than this.
Even so to produce 9A for one hour you’ll need at least 100W and given inefficiencies and not direct sunshine then you’ll be looking the biggest you can get say 150W.
Unfortunately absorption fridges are very hungry on power, whereas the compressor type are less so. I hope you manage to find a solution.
Hope this helps
- You must be logged in to reply to this topic.