Design and Install Questions
- Thread starter 95RRC
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cruiseroutfit
Well-known member
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95RRC
Adventurer
Really, I just figured it was not going to get answered - at all.
This is for onboard electrical application for a trailer.
Well I am looking for advise on a complete electrical setup/design. I am going to make a box to house two AGM batteries (like these - OPTIMA® Batteries 8027-127 D27M 27 BLUETOP® Marine/RV (Deep-Cycle & Starting), I know I need to link these together then run the pos side of one and the negative side of another to a "junction box" or fuse box. Then from the fuse box I go to the desired application - like a fridge port(wired in cig lighter) or direct to a switch for lighting on the trailer.
I want to be able to power up:
Fridge - 50L Ironman4x4
LED camp lights on the trailer - and in it - probably at least 10
Radio and speakers
Charge iPhones and the like via USB charging ports
Maybe even put a 1000W Inverter on
Then comes the charging part for the batteries. I have two things to accomplish:
1. Anderson plugs - not sure how these wire up - but assume they go from the alternator on the tow vehicle - but do they go to a charger of some sort that is then hooked to the battery?
2. Solar charging
3. Trickle charge for at home and at campsites with 120V hookup
So these areas are where I have the most questions. What is the best thing to buy, and where to source it.
I am thinking of:
flexible solar panels so they can be rolled up and laid out - with a 100W charging ability
a solar controller unit? What type etc? dunno...
a trickle charger of some sort??? for when the trailer is not in use - plug in to an outlet at the house???
Do I need a "main battery" switch to turn the batteries off - between the battery and the fuse unit??? - if so - what is good?
SO I am looking into design/wiring/installing guidelines or advice.
Thanks - I will leave this up now.
This is for onboard electrical application for a trailer.
Well I am looking for advise on a complete electrical setup/design. I am going to make a box to house two AGM batteries (like these - OPTIMA® Batteries 8027-127 D27M 27 BLUETOP® Marine/RV (Deep-Cycle & Starting), I know I need to link these together then run the pos side of one and the negative side of another to a "junction box" or fuse box. Then from the fuse box I go to the desired application - like a fridge port(wired in cig lighter) or direct to a switch for lighting on the trailer.
I want to be able to power up:
Fridge - 50L Ironman4x4
LED camp lights on the trailer - and in it - probably at least 10
Radio and speakers
Charge iPhones and the like via USB charging ports
Maybe even put a 1000W Inverter on
Then comes the charging part for the batteries. I have two things to accomplish:
1. Anderson plugs - not sure how these wire up - but assume they go from the alternator on the tow vehicle - but do they go to a charger of some sort that is then hooked to the battery?
2. Solar charging
3. Trickle charge for at home and at campsites with 120V hookup
So these areas are where I have the most questions. What is the best thing to buy, and where to source it.
I am thinking of:
flexible solar panels so they can be rolled up and laid out - with a 100W charging ability
a solar controller unit? What type etc? dunno...
a trickle charger of some sort??? for when the trailer is not in use - plug in to an outlet at the house???
Do I need a "main battery" switch to turn the batteries off - between the battery and the fuse unit??? - if so - what is good?
SO I am looking into design/wiring/installing guidelines or advice.
Thanks - I will leave this up now.
I'll be able to take a better look at this later, but pretty much you first need to get a good number on your daily power needs. This value can be either Amp hours (Ah) or Watt hours (Wh). I like to use Ah personally.
For example, if your "Radio and speakers" use .7 amps and you want to be able to run them for 3 hours per day, you will use .7 Amps per hour. So at 3 hours, you will have used 2.1 Amps. You can also say this as you used 2.1Ah from the battery.
Once you add up all of your daily power needs, you need to add a little more. After I find my daily (Ah) number, I usually add another 25% to that to be safe to come up with my "Safe Ah value". Next would be how many days you want to run this "Safe Ah value". Multiply the "Safe Ah value" by the number of days you want to run everything and you come up with the "Long-Term Ah value".
Now for the battery selection, one thing to keep in mind is you don't want to bring the battery below 50% capacity too many times. Best practice is to have all of your "Long Term Ah" needs in the top 50% of the battery. So multiply your "Long-Term Ah value" by 2. This should be your minimum, bottom dollar, don't get less than Ah rating for your battery(s).
Now with solar, you can offset the batteries from reaching the 50% mark and in some cases (depending on how much solar you will have), you can even sustain your batteries at 100% each day.
For example, if your "Radio and speakers" use .7 amps and you want to be able to run them for 3 hours per day, you will use .7 Amps per hour. So at 3 hours, you will have used 2.1 Amps. You can also say this as you used 2.1Ah from the battery.
Once you add up all of your daily power needs, you need to add a little more. After I find my daily (Ah) number, I usually add another 25% to that to be safe to come up with my "Safe Ah value". Next would be how many days you want to run this "Safe Ah value". Multiply the "Safe Ah value" by the number of days you want to run everything and you come up with the "Long-Term Ah value".
Now for the battery selection, one thing to keep in mind is you don't want to bring the battery below 50% capacity too many times. Best practice is to have all of your "Long Term Ah" needs in the top 50% of the battery. So multiply your "Long-Term Ah value" by 2. This should be your minimum, bottom dollar, don't get less than Ah rating for your battery(s).
Now with solar, you can offset the batteries from reaching the 50% mark and in some cases (depending on how much solar you will have), you can even sustain your batteries at 100% each day.
95RRC
Adventurer
Thanks Lysol....so here goes (btw I am in Leesburg)
Radio & Speakers - lets assume .7Ah/h @3hrs per day = 2.1amps/day
Fridge - .7Ah/h @24hrs per day = 16.8amps/day
Lights - lets assume 1Ah/h @ 4hrs per day (x10) = 40amps/day
Other - lets just guestimate at 20amps/day for everything else (charging accessories, using a blender etc...)
SO - that gets me daily usage of roughly 79amps/day - so say 80amps/day (which is also inclusive a pretty good 20amps or so buffer)
I plan on having 2x Deep Cycle AGM batteries roughly 100Ah each - total is 200Ah
So 200Ah availability and a 80Ah per day usage = reserve of 120Ah or said another way I will use 40% of my batteries each day.
So I was planning on a 100W solar panel with a controller which I have read puts back 7-9amps per hr = perfect world of 8hrs daylight = approx 56amps put back (more than my drain)
IS ALL THAT RIGHT?????????
Radio & Speakers - lets assume .7Ah/h @3hrs per day = 2.1amps/day
Fridge - .7Ah/h @24hrs per day = 16.8amps/day
Lights - lets assume 1Ah/h @ 4hrs per day (x10) = 40amps/day
Other - lets just guestimate at 20amps/day for everything else (charging accessories, using a blender etc...)
SO - that gets me daily usage of roughly 79amps/day - so say 80amps/day (which is also inclusive a pretty good 20amps or so buffer)
I plan on having 2x Deep Cycle AGM batteries roughly 100Ah each - total is 200Ah
So 200Ah availability and a 80Ah per day usage = reserve of 120Ah or said another way I will use 40% of my batteries each day.
So I was planning on a 100W solar panel with a controller which I have read puts back 7-9amps per hr = perfect world of 8hrs daylight = approx 56amps put back (more than my drain)
IS ALL THAT RIGHT?????????
Thanks Lysol....so here goes (btw I am in Leesburg)
Radio & Speakers - lets assume .7Ah/h @3hrs per day = 2.1amps/day
Fridge - .7Ah/h @24hrs per day = 16.8amps/day
Lights - lets assume 1Ah/h @ 4hrs per day (x10) = 40amps/day
Other - lets just guestimate at 20amps/day for everything else (charging accessories, using a blender etc...)
SO - that gets me daily usage of roughly 79amps/day - so say 80amps/day (which is also inclusive a pretty good 20amps or so buffer)
I plan on having 2x Deep Cycle AGM batteries roughly 100Ah each - total is 200Ah
So 200Ah availability and a 80Ah per day usage = reserve of 120Ah or said another way I will use 40% of my batteries each day.
So I was planning on a 100W solar panel with a controller which I have read puts back 7-9amps per hr = perfect world of 8hrs daylight = approx 56amps put back (more than my drain)
IS ALL THAT RIGHT?????????
I read somewhere that you generally want to shoot for making all of the solar power you want in just a 4-hour window. This is because that most of your panels output will be during the peak hours of the day. If you actually end up using on average 80Ah per day and you want to fully sustain that by replenishing it each day, you'll want around 250 Watts worth of solar power to guarantee you get all of your power back the next day. Now, this is of course a "comfortable" number. I'm sure you could get by with less if you always have a bright sun shining.
With the battery, you normally don't want to take it/them past 50% Depth of Discharge (DOD). If you have a battery that's rated at 100Ah, then this could be said as you normally don't want to take it below 50Ah. If you have (2) 12V 100Ah batteries wired in parallel to give you a total of 200Ah's at 12V, then you wouldn't want to discharge them below 100Ah. Every battery has a chart in it's manual/user's guide that shows an approximate number of times you can cycle the battery past certain DOD's. Heck, some people don't like to take their batteries below 80%. It all depends on how often you would like to replace the battery. Generally, deep-cycle batteries can "handle" being taken down to low DOD's more than a starting battery. It's due to them using thicker lead plates.
I'm using a motorcycle AGM-type (Absorbed Glass Mat) battery in my mini solar generator. It only gives me around 15Ah total. I plan to discharge it down to around the 50% DOD mark if I have to. I just know that when I start to see poor performance from it, I'll replace it. Simple as that.
I would also try to memorize the percentages for 12V batteries. This has helped me really start to understand the battery state just from looking at the voltage reading.
An example of what you might see in a battery's user manual regarding Cycle Life and Depth of Charge (notice how discharging the battery only 30% each time greatly increases the life of the battery versus discharging it 100% and only getting around 200 cycles(1 cycle is seen as discharging it and recharging it)):
Last edited:
Jr_Explorer
Explorer
An example of what you might see in a battery's user manual regarding Cycle Life and Depth of Charge (notice how discharging the battery only 30% each time greatly increases the lift of the battery versus discharging it 100% and only getting around 200 cycles(1 cycle is seen as discharging it and recharging it)):
The above strikes to one comment I was going to make. You really should plan on only 20%-30% DOD if you want to get years and years out of your batteries (if they are AGM's). Also... I think 7-9 amps out of a 100 watt panel may be optimistic (I think I've sen those types of numbers for 140 watt panels).
I'll throw this out again: http://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/ Ol' Handy Bob has a TON of good info on his site/blog.