1x20A Controller (I have 3 more controllers all 20A, but I was told they dont work together)
1xDual Cycle 140A Battery
1xInverter 3000 to 6000
I want to run:
1x 57l 12v Fridge
2xled lights (little!)
1x laptop (it takes about 30' to charge)
1xphone (straight from the controller)
1xwifi modem (straight from the controller)
1xOne burner stove - Rated Power (whatever this means) 2000W
My battery is connected to the van's battery but as I am not driving much (nothing really) it is not charging.
I just learned that the inverter use a lot of power to run itself and that I should turn it off whenever I am not actually using it.
Whatever could I do to maximise my power? Would I have to buy some Lithium battery? A 100A Controller? More solar panel? I am lost! Please, can someone help me?
I am not using the stove because there is not enough power.
-- Edited by Eremita on Friday 25th of June 2021 11:58:16 AM
-- Edited by Eremita on Friday 25th of June 2021 11:59:31 AM
As Dicko said there is lots of information here in the Techies Corner and up the top in the Solar Power sub forum.
But to give my quick opinion first off.
Your one 140Ahr( ? ) battery is not enough to run your big inverter and that electric stove. I suggest that you use a small gas stove with the small cans of gas for a start until you get things sorted better. We use those !
It is true that inverters do use some power when standing by and turning it off would save power, and some are more inefficient than others with no load or small loads.
Tell us what your regulators are and your solar panel specs. Certainly one 20A regulator will not handle the three panels @ 900W so you are throttling them now. We might suggest a better quality reg or some better setup.
Your fridge is 12V so that is good if it is a compressor type. If it is a 3 way type then not good. I would suggest you give us the model and type of all you items so we can better advise you.
I bought a couple of good books years ago to learn about this stuff and still recommend it. Colyn Rivers wrote several still available.
Running a 2000 watt piece of equipment from a 140 a/h agm is crazy. Thats over 170 amps!!! A 140 a/h agm is good for around 70-80 amps...using the 50% rule for battery longevity. Thats also assuming it is a true 140a/h battery. Kickass for example are advertised as 140 but specs are closer to 110a/h. Ditch the inverter and get gas cooking...otherwise if you insist on using a 2000watt appliance you will need to go lithium or a lot more agm batteries.
Dick0 is correct....browse the forum and you,ll get your answers.
If they really are 3 x 300 watt panels, that is a huge amount for a caravan. No problem if they all fit and are secured properly. That should be sufficient to provide charging capability for what you want. That should give you maybe 45-50 amps per hour in perfect conditions. But. .... not so easy.
First, how do you store the energy? A single 140 amp/hr battery would be insufficient on a daily basis.
As already noted, you need a bigger solar charger. And the electric stove is the main killer that makes the solution unfeasible. For the other stuff you really need to check specs and work an energy budget. How many amps will your fridge consume in 24 hours in tropical conditions. It may run non stop. How long will you run the laptop for? I have made some guestimates to get you started.
Fridge, assuming 18 hours cycle on time at 4 amps = 72 amps Laptop, assume 4 hours daily incl TV, etc at 4 amps = 16 amps Inverter overhead 4 hours at 1 amp = 4 amps Wifi (turned off when not in use), phone and lights = 4 amps
Your guideline should be to stay within 50% discharge of your battery capacity so you need 200 amp/hrs of battery capacity to last 24 hours. What do you do if there there are 3 consecutive rainy days with virtually zero charge going in? If you have a generator to fill in for those days then maybe.
So, get back with some specs and more detail on what you have. Also, are you aware that most solar panels sold fall well short of their advertised specs. Measure your solar panels. About the best you should expect from common solar panels is 170 watts per square metre, and that is a theoretical "best conditions" figure.
The same overspecced situation applies to batteries. A good 140 amp/hr battery will weigh about 40kg or more. If it weighs less it is unlikely to be 140 amp/hrs. What do you mean by "dual cycle" battery?
-- Edited by Are We Lost on Friday 25th of June 2021 07:14:55 PM
Geez guys! I didnt expect you would answer so promptly and with so many good advices! Thank you!
I dont know much about my system for I paid a guy to do it for me and he doesnt have much (none) experience either! Well, starting from the bottom up, the battery is extremely heavy - really heavy. But I will get all the details - and it is not "dual cycle"it is Deep Cycle! I am so stressed out that some times I mess things up.
I have already got a gas stove and it is going well - I have nothing against gas stove, I just was afraid I would burn the van down. By the way, my van is a Ford Transit 2005.
The AGM Battery is connected to the car's battery and if I could drive around it would fill up, but I cant drive just now, so some times I turn the car on and let it run for half an hour or so.
It is dark now and I cannot find the information about the system but I will look for it first time in the morning.
Another thing I want to ask is what is the best set up for the panels, if parallel or series.
Since you have 3 panels I would install in parallel. If you had 4 then 2 in series then 2 sets. Having 3 in parallel if one panel fails you still have 2/3 of your array
You will need decent wiring so you don't throw away all the amps in heat.
Draw up a scale wiring plan with all the distance. I would have a switch on each of the 3 panels near the controller so you can isolate any of them if there is a fault for testing.
Easier to do this now than fiddle while camping.
Once you have your wiring distances you can then calculate the cross sectional area of each wire & each segment.
The wire resistance is the total length of the wire. If it is 4 metres, it is actually 8 metres for both positive and negative.
A simple calculation for 8 metres ( + & - ) but you need to have cable to each panel (see chart).
Even though this chart recommends 4awg, personally I would use 2awg. But you do have 900 watts & under ideal conditions you could afford to waste a bit of energy.
Having said that, are the panels actually 300 watts. It would be worthwhile measuring their size & calculate the output at say 150 watts per square metre & if they are quality panels at 170 watts per square metre.
If there is an unrealistically high figure (marketing BS) you could scale down the wiring & controller accordingly.
As others have said I would forget battery power for cooking. Use gas or metho. At the very least, until you get your head around the sheer volume of energy required for cooking. I have a 3.0kVA (2700 watt) UPS (uninterruptible power supply) for computers with extended battery backup.
I tried this once when the batteries were still good. I put the exact amount of water in our 2200 watt kettle to boil a cup of water. 1 minute to boil & 10% of my backup resources gone.
If you insist on boiling water & you have increased your battery capacity 3 or 4 fold, get a Birko 750 watt kettle. The lower the wattage over a long period of use the better off the batteries are.
If you have a three way fridge use gas. If you have a compressor fridge you will be ok. There are a few things here you can easily do to improve efficiency.
So you do not have to run the inverter around the clock for your electric toothbrush, bet a Braun AA battery toothbrush, we have one each. They are not quite as good, but are acceptable. You can use rechargeable batteries & charge via 12 volt charger.
Look at 12 volts for everything else or 12 volts to USB. The only expensive piece of equipment we had to buy to be completely on 12 volts was a Canon battery charger for DSLR camera.
With a bit of careful planning & design you can be completely on 12 volts. Or at the very least a minimal of 240 & your 900 watts of solar will supply your energy needs in low latitudes in winter.
Start by working out the loads of each piece of equipment. Work out wiring length for your complete network. Then calculations can easily be done to get it right the first time saving money!
__________________
Procrastination, mankind's greatest labour saving device!
50L custom fuel rack 6x20W 100/20mppt 4x26Ah gel 28L super insulated fridge TPMS 3 ARB compressors heatsink fan cooled 4L tank aftercooler Air/water OCD cleaning 4 stage car acoustic insulation.
Here are are few of my posts which will bore you to death. But at the end of the day it is a lot easier & cheaper to do homework & get things right first time!
There is a lot of information throughout this website if you spend some time tediously going through the threads to pick up ideas even if you do not use the information for your current project.
__________________
Procrastination, mankind's greatest labour saving device!
50L custom fuel rack 6x20W 100/20mppt 4x26Ah gel 28L super insulated fridge TPMS 3 ARB compressors heatsink fan cooled 4L tank aftercooler Air/water OCD cleaning 4 stage car acoustic insulation.
Geez guys! I didnt expect you would answer so promptly and with so many good advices! Thank you! I dont know much about my system for I paid a guy to do it for me and he doesnt have much (none) experience either! Well, starting from the bottom up, the battery is extremely heavy - really heavy. But I will get all the details - and it is not "dual cycle"it is Deep Cycle! I am so stressed out that some times I mess things up. I have already got a gas stove and it is going well - I have nothing against gas stove, I just was afraid I would burn the van down. By the way, my van is a Ford Transit 2005. The AGM Battery is connected to the car's battery and if I could drive around it would fill up, but I cant drive just now, so some times I turn the car on and let it run for half an hour or so. It is dark now and I cannot find the information about the system but I will look for it first time in the morning. Another thing I want to ask is what is the best set up for the panels, if parallel or series. Thank you very much. ________________________________________________________________________________________________________________________-
Hi Emerita
Do not stress this forum knows everything and will help you !
The first thing I would like you to check is the specs sticker and brand on the solar panels as that is important to see what they really are. I have never seen 300W 12V panels so the choice of a controller/regulator is very important to get the most out of them. Leave the series/parallel choice just yet.
What is the 'connection' between the house battery and the engine battery ? Is it a VSR or relay or other ? If you do not know the answer just say that and look at what was bought.
Geez guys! I didnt expect you would answer so promptly and with so many good advices! Thank you! I dont know much about my system for I paid a guy to do it for me and he doesnt have much (none) experience either! Well, starting from the bottom up, the battery is extremely heavy - really heavy. But I will get all the details - and it is not "dual cycle"it is Deep Cycle! I am so stressed out that some times I mess things up. I have already got a gas stove and it is going well - I have nothing against gas stove, I just was afraid I would burn the van down. By the way, my van is a Ford Transit 2005. The AGM Battery is connected to the car's battery and if I could drive around it would fill up, but I cant drive just now, so some times I turn the car on and let it run for half an hour or so. It is dark now and I cannot find the information about the system but I will look for it first time in the morning. Another thing I want to ask is what is the best set up for the panels, if parallel or series. Thank you very much. ________________________________________________________________________________________________________________________-
Hi Emerita
Do not stress this forum knows everything and will help you !
The first thing I would like you to check is the specs sticker and brand on the solar panels as that is important to see what they really are. I have never seen 300W 12V panels so the choice of a controller/regulator is very important to get the most out of them. Leave the series/parallel choice just yet. PLENTY OF 300WATT PORTABLE 12 VOLT STYLE FOR CAMPING AVAILABLE JAAHN.
What is the 'connection' between the house battery and the engine battery ? Is it a VSR or relay or other ? If you do not know the answer just say that and look at what was bought.
It would be interesting to see how one can get a 300 watt panel in a vehicle. If it is in fact actually 300 watts to start with. But I assume people have done their due diligence & benchmarked the panel.
At about 1.7m² not exactly easily to stick it in the boot.
It's the reason my panel is actually in 6 sections.
__________________
Procrastination, mankind's greatest labour saving device!
50L custom fuel rack 6x20W 100/20mppt 4x26Ah gel 28L super insulated fridge TPMS 3 ARB compressors heatsink fan cooled 4L tank aftercooler Air/water OCD cleaning 4 stage car acoustic insulation.
The first thing I would like you to check is the specs sticker and brand on the solar panels as that is important to see what they really are. I have never seen 300W 12V panels so the choice of a controller/regulator is very important to get the most out of them. Leave the series/parallel choice just yet.
Dicko1 wrote; PLENTY OF 300WATT PORTABLE 12 VOLT STYLE FOR CAMPING AVAILABLE JAAHN.
Hi
Possibly, I never thought to look as I would consider them unsuited to mobile use. I have always said panels about 80-100W are best for a variety of reasons. Would you want a sheet of window glass that big on your roof at speed on a dirt road. AND as said where the hell do you store them as portable panels.
Hmm buying on price only may lead to a poor result.
It would be interesting to see how one can get a 300 watt panel in a vehicle. If it is in fact actually 300 watts to start with. But I assume people have done their due diligence & benchmarked the panel.
At about 1.7m² not exactly easily to stick it in the boot.
It's the reason my panel is actually in 6 sections.
You're onto it Jonathan.My Qcell 300 watts are 1650x1000mm.Cheers
Is it possible, the 20amp controller is overloaded and therefore not working?
What happens to charging in such circumstance? Does the controller only allow 20amps through (240w) which is less than 1 panel of 3?
Go gas cooking we use the Lido junior.
See my thread posted recently on charging an AGM battery in cloudy weather only a few threads down from this one. Jonathan (whenarewethere) and Jaahn we most helpful and others.
Welcome to the forum.
Tony
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Be nice... if I wanted my school teacher here I would have invited him...
I can only speak for my Victron 75/10 MPPT Bluetooth controller. According to the controller & also an analogue amp meter. I get up to 7.8amps or 3.9amps with 2 panels in series from 120 watts.
The output of the controller stops at 10amps. The manual says up to 145 watts input, but as the output stops at 10amps having more solar is not going to give you more amps output.
If it is less than ideal conditions having 145watts will help as you won't reach the 10amp output limit.
But quite frankly one might as well get all the sun you can when you can.
So I replaced the 75/10 with a 100/20. I could have gone with a 75/15, but I thought I'd get the largest in this range. It also has a heat sink (which I have further improved) so if the ambient temperature is very high the controller has a lot of headroom.
With the new 100/20 controller, at times it is a bit over 10amps output & up to 11.3amps. Not a lot extra, but why not use it if it's there.
I also have the option of getting another 80 watts of panels & still be well within the 20amp output. At this stage 120watts is plenty for our use.
We are really squeezing every last watt out of our system with extra heavy wiring.
Personally I would rather have a smaller system with quality components. I don't want to be fiddling around in the outback with third rate circus.
We also take the 75/10 as a backup. With multiple solar panels, multiple batteries & multiple controllers we are pretty well covered with redundancy.
__________________
Procrastination, mankind's greatest labour saving device!
50L custom fuel rack 6x20W 100/20mppt 4x26Ah gel 28L super insulated fridge TPMS 3 ARB compressors heatsink fan cooled 4L tank aftercooler Air/water OCD cleaning 4 stage car acoustic insulation.
AND as said where the hell do you store them as portable panels.
