ckent323
Senior Member
I have the impression that a number of people start with the Solar panels when planning to add solar power to their camper (like I did). So I thought it might be helpful to write a short set of steps to start to process, with the hope that it will help minimize iterations and confusion for folks wanting to add Solar.
Caveat emptor: I am not an expert on this subject but I have read a lot on the topic and I have installed my own Solar System on my camper. I hope I have not omitted any significant steps or considerations.
Note: - This has been edited to include recommendations from Rando's comments in the reply thread (below)
1 [SIZE=10.5pt] [/SIZE]Determine your daily power consumption from all sources. Make a spreadsheet and estimate power use by device per day in winter and in summer. Determine typical and worst case power consumption.
[SIZE=10.5pt]- Better yet [/SIZE][SIZE=10.5pt]measure your power usage (assuming you already have the camper and are currently using it without solar). Do this to avoid over estimating power needs. There is tendency to add up everything in the camper and worst case run times, then call that number the typical usage. [/SIZE]
[SIZE=10.5pt]- [/SIZE][SIZE=10.5pt]To accomplish this consider investing in a battery monitor first ([/SIZE][SIZE=10.5pt]Victron BMV-712[/SIZE][SIZE=10.5pt]) or break out your voltmeter and do some careful state of charge (SOC) measurements to see what your actual usage is. Your loads may not actually add - when it is hot out, the fridge runs a lot, but you don't use the furnace and don't use the lights much. When it is cold out the fridge and fans don't run much, but you run the furnace and lights more. 30-40Ah /day seems to be a pretty reasonable average, but everyone's usage varies based on equipment and lifestyle. [/SIZE]
[SIZE=10.5pt](Note: If you use a CPAP as well as the humidifier and power it from the house battery your power needs could easily be another 40 or 50 Ah a day on top of the other items included in your measurements or estimates above. You may want to consider a separate portable [/SIZE]rechargeable[SIZE=10.5pt] CPAP battery, especially if you have access to shore power or move around frequently and can recharge from your vehicle while driving).[/SIZE]
2 Determine the environment you will most often be in and how many nights a year you will use your camper: clear, cloudy, on pavement (modest vibration and bouncing), off pavement (perhaps significant vibration and bouncing). The answers to this will help you choose the battery type and the storage capacity you need. It will also help you determine the size of the Solar panel bank that you need to recharge the battery bank.
3 Determine what kind of battery storage and capacity you need/want.
- Deep Cycle, mixed or starting type,
- Flooded lead acid (FLA) , Absorbed Gas Matt (AGM), Gell, or Lithium Iron Phosphate (LiFePO4). Each type has its pros and cons.
- Look at Depth of Discharge (DOD) vs Charge Cycles (lifetime) curves relative to your typical power needs and the type of battery you choose. (This may lead you to considering a different battery type). If you do not use your camper more than 20 or 30 nights a year you can draw your battery down significantly further on a routine basis than if you use it 60 or more nights a year (see discussion in the comment/reply thread below).
- Look at battery orientation, venting and shock protection requirements (for example sealed batteries can be mounted on their sides and do not require venting - Gell may be more resistant to shock bouncing than AGM)
4 Think about where you will house your battery bank
- Weight and volume (size) of the batteries
- Where will they fit and where will you run the wires and place the Solar control panel?
5 Think about where you will place the Solar Panels
- [SIZE=10.5pt]Weight and size (length and width) [/SIZE]of the solar panels
- Do you want the Solar panels to be fixed in place, deployable or a combination
- Where will you run the wires to connect to the charge control panel and the batteries?
6 Determine how much Solar Power you need each day and the number of panels that requires
- How much power per day will the house batteries receive from the vehicle? Do you tend to move around a lot or stay in one place. Sizing of the wires from the vehicle to the camper is important and wires smaller than around 4 ga or 6 ga can significantly reduce the amount of power available to the batteries (cause recharging to take longer)
- Solar panels (like Batteries) are rated by full or max capacity. On average a solar panel only provides about 75% - 80% of peak output during the day on a clear sunny day and even less on cloudy days so factor that into your calculations. Also keep in mind that any shadow, even a small shadow from a branch or even a leaf can significantly reduce the output from a solar panel, so where you park your camper is important if the panels are fixed on the camper.
- Look at the cost performance trade between using fewer higher output capacity solar panels (larger in length & width) with output nominally 24v versus more, lower output capacity panels (smaller in length & width) with output nominally 12 v. Note: Your Solar Charge controller will need to be able to support the type of panel you choose (12 V or 24 V as well as the max current output of the Solar Panel array).
That about covers the steps to start with.
What charge controller and what configuration is best for connecting your battery bank and Solar Panels are among the next set of steps but beyond the scope of this set of initial steps of where to start.
I hope this is helpful.
Regards,
Craig
[SIZE=10.5pt]- [/SIZE]
Caveat emptor: I am not an expert on this subject but I have read a lot on the topic and I have installed my own Solar System on my camper. I hope I have not omitted any significant steps or considerations.
Solar Power for your Camper – Where to Start (Hint: The Solar Panels are last in this list of steps)
Note: - This has been edited to include recommendations from Rando's comments in the reply thread (below)
1 [SIZE=10.5pt] [/SIZE]Determine your daily power consumption from all sources. Make a spreadsheet and estimate power use by device per day in winter and in summer. Determine typical and worst case power consumption.
[SIZE=10.5pt]- Better yet [/SIZE][SIZE=10.5pt]measure your power usage (assuming you already have the camper and are currently using it without solar). Do this to avoid over estimating power needs. There is tendency to add up everything in the camper and worst case run times, then call that number the typical usage. [/SIZE]
[SIZE=10.5pt]- [/SIZE][SIZE=10.5pt]To accomplish this consider investing in a battery monitor first ([/SIZE][SIZE=10.5pt]Victron BMV-712[/SIZE][SIZE=10.5pt]) or break out your voltmeter and do some careful state of charge (SOC) measurements to see what your actual usage is. Your loads may not actually add - when it is hot out, the fridge runs a lot, but you don't use the furnace and don't use the lights much. When it is cold out the fridge and fans don't run much, but you run the furnace and lights more. 30-40Ah /day seems to be a pretty reasonable average, but everyone's usage varies based on equipment and lifestyle. [/SIZE]
[SIZE=10.5pt](Note: If you use a CPAP as well as the humidifier and power it from the house battery your power needs could easily be another 40 or 50 Ah a day on top of the other items included in your measurements or estimates above. You may want to consider a separate portable [/SIZE]rechargeable[SIZE=10.5pt] CPAP battery, especially if you have access to shore power or move around frequently and can recharge from your vehicle while driving).[/SIZE]
2 Determine the environment you will most often be in and how many nights a year you will use your camper: clear, cloudy, on pavement (modest vibration and bouncing), off pavement (perhaps significant vibration and bouncing). The answers to this will help you choose the battery type and the storage capacity you need. It will also help you determine the size of the Solar panel bank that you need to recharge the battery bank.
3 Determine what kind of battery storage and capacity you need/want.
- Deep Cycle, mixed or starting type,
- Flooded lead acid (FLA) , Absorbed Gas Matt (AGM), Gell, or Lithium Iron Phosphate (LiFePO4). Each type has its pros and cons.
- Look at Depth of Discharge (DOD) vs Charge Cycles (lifetime) curves relative to your typical power needs and the type of battery you choose. (This may lead you to considering a different battery type). If you do not use your camper more than 20 or 30 nights a year you can draw your battery down significantly further on a routine basis than if you use it 60 or more nights a year (see discussion in the comment/reply thread below).
- Look at battery orientation, venting and shock protection requirements (for example sealed batteries can be mounted on their sides and do not require venting - Gell may be more resistant to shock bouncing than AGM)
4 Think about where you will house your battery bank
- Weight and volume (size) of the batteries
- Where will they fit and where will you run the wires and place the Solar control panel?
5 Think about where you will place the Solar Panels
- [SIZE=10.5pt]Weight and size (length and width) [/SIZE]of the solar panels
- Do you want the Solar panels to be fixed in place, deployable or a combination
- Where will you run the wires to connect to the charge control panel and the batteries?
6 Determine how much Solar Power you need each day and the number of panels that requires
- How much power per day will the house batteries receive from the vehicle? Do you tend to move around a lot or stay in one place. Sizing of the wires from the vehicle to the camper is important and wires smaller than around 4 ga or 6 ga can significantly reduce the amount of power available to the batteries (cause recharging to take longer)
- Solar panels (like Batteries) are rated by full or max capacity. On average a solar panel only provides about 75% - 80% of peak output during the day on a clear sunny day and even less on cloudy days so factor that into your calculations. Also keep in mind that any shadow, even a small shadow from a branch or even a leaf can significantly reduce the output from a solar panel, so where you park your camper is important if the panels are fixed on the camper.
- Look at the cost performance trade between using fewer higher output capacity solar panels (larger in length & width) with output nominally 24v versus more, lower output capacity panels (smaller in length & width) with output nominally 12 v. Note: Your Solar Charge controller will need to be able to support the type of panel you choose (12 V or 24 V as well as the max current output of the Solar Panel array).
That about covers the steps to start with.
What charge controller and what configuration is best for connecting your battery bank and Solar Panels are among the next set of steps but beyond the scope of this set of initial steps of where to start.
I hope this is helpful.
Regards,
Craig
[SIZE=10.5pt]- [/SIZE]