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Post by fish on Jul 30, 2023 9:38:46 GMT 12
There is a random thing with solar controllers. You can go with panels of higher wattage than the controller's rated amperage. I think by 25%. I first read about this on a Victron technical paper. I think I've seen it for other brands as well. I think you wont / can't get more than 10 amps out of the controller, bit you can have bigger panels going in. The logic is that you very rarely get the full power out of a panel, due to sun angle, shading and deteriation of panel performance. The controllers have sufficient redundancy and safety features to tolerate an amount of excess wattage from time to time. This means you can optimise your panels to capture more sun / watts on the shoulder periods of the day, on the basis that you can't get more than the controllers rated wattage at the peak time (which hardly ever occurs. I was looking at putting on a new 15a Victron controller, and technically that would have limited me to 180 watt panels. There are a lot of panels on the market at 200 watt, so far more choice and generally a better price point. Turns out that going slightly over is perfectly acceptable for the Victron controller, and likely the same for the Epevers. The Epever manual states, in the best Chinese-English If the maximum power of PV array exceeds the rated charging power of the controller too much, it will not only cause the waste of PV modules but also increase the open circuit voltage of the PV array due to the influence of environmental temperature which may make the probability of damage to the controller ariseEpever 10amp controller rated for Max PV array power 195W/12V, so you would probably get away with this for a 200W panel. Not sure if there is any real benefit going down this road as against using a 20amp controller I have thought about upgrading my 110's to 200's but the only concern is the size of the latter, 1500 x 670, just about the size of a door! That is a very good example CZ. A lot of people would think a 10 amp controller can only handle a 120 watt panel. (12v x 10amp=120watt). But that 10 amp controller is stated as handling 195watts, in theory 16.25 amps (195 watt / 12 volt = 16.25 amp)
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Post by GO30 on Jul 30, 2023 10:06:36 GMT 12
CZ's mounting system is the most common seen, very simple and effective. Also can be tweaked to suit most boats quite easily. If you had some say 40mm x 2mm SS strap you could bend the brackets to wrap around the pushpit yourself. My EPEVER controller states a maximum PV array shall not be more than 1.5 times the controllers rated charging power. That possibly allows for system drag and leakage? It's a 60amp and it rated at 750W/12V with a maximum of 1125W/12V. I am assuming you are on 12V, I'm on 24 so can run twice the 12V wattage, if 36 then 3 times, if 48V then 4 times the 12V numbers. Currently feeding that controller is 1590W of panels. 4 of them in 2 sets Paralleled then those Series or the other way around, I always get them confused. I see between 65 and 79V coming off them depending on the day. Right now it's 77V and 9.2amps coming in, 28.9V and 29.6amps going out. In an hour or so they will drop off to bugger all. The panels are 390W each, 1750 x 1090mm. They don't seem much bigger than CZ's suggested 200W which seems a little ? This morning I was pondering putting in a 2V controller and battery system as 11pm last night the PV's were putting out 7V. I could run a Moon powered beer fridge No idea if that would work but with the right gear it should...shouldn't it?
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Post by ComfortZone on Jul 30, 2023 10:59:36 GMT 12
The Epever manual states, in the best Chinese-English If the maximum power of PV array exceeds the rated charging power of the controller too much, it will not only cause the waste of PV modules but also increase the open circuit voltage of the PV array due to the influence of environmental temperature which may make the probability of damage to the controller ariseEpever 10amp controller rated for Max PV array power 195W/12V, so you would probably get away with this for a 200W panel. Not sure if there is any real benefit going down this road as against using a 20amp controller I have thought about upgrading my 110's to 200's but the only concern is the size of the latter, 1500 x 670, just about the size of a door! That is a very good example CZ. A lot of people would think a 10 amp controller can only handle a 120 watt panel. (12v x 10amp=120watt). But that 10 amp controller is stated as handling 195watts, in theory 16.25 amps (195 watt / 12 volt = 16.25 amp) Fish, you need to be careful using a nominal 12V in calculations, it is not what is actually happening. The Epever manual states the Tracer 1210 has a rated charge current of 10A, rated charge power of 130W and Max PV array of 195W. The rated charge power of 130W equates to a charge of 10amps at 13V, which is a little on the low side for a charging voltage. My controller shows the panel on open circuit as 21V, when charging with some grunt around 18V, which once again approximates to 10 amps.
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Post by fish on Jul 30, 2023 11:51:03 GMT 12
That is a very good example CZ. A lot of people would think a 10 amp controller can only handle a 120 watt panel. (12v x 10amp=120watt). But that 10 amp controller is stated as handling 195watts, in theory 16.25 amps (195 watt / 12 volt = 16.25 amp) Fish, you need to be careful using a nominal 12V in calculations, it is not what is actually happening. The Epever manual states the Tracer 1210 has a rated charge current of 10A, rated charge power of 130W and Max PV array of 195W. The rated charge power of 130W equates to a charge of 10amps at 13V, which is a little on the low side for a charging voltage. My controller shows the panel on open circuit as 21V, when charging with some grunt around 18V, which once again approximates to 10 amps. Absolutely agree. But a lot of people will assume that it is a straight power = volts x amps equation to determine how big a panel you can put on a 10 amp controller. The point being that most controllers can handle a bigger panel than based on that simple calculation. It is the danger of a little knowledge, or, not knowing what you don't know. How many males do you know that read the manual BEFORE trying to do something?
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Post by jim on Jul 31, 2023 19:20:51 GMT 12
Some years back i made up mounting hardware for panels on each side of the pushpit. I used a selection of aluminium flat bar and angle and machined up the pieces to match the (1"?) railing and to evenly support the panels . I'm a long way from that boat so can't take photos but have some holiday (remember them?) photos with the setup in view Attachments:
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Post by Fogg on Jul 31, 2023 19:30:49 GMT 12
Some years back i made up mounting hardware for panels on each side of the pushpit. I used a selection of aluminium flat bar and angle and machined up the pieces to match the (1"?) railing and to evenly support the panels . I'm a long way from that boat so can't take photos but have some holiday (remember them?) photos with the setup in view - how do i add photos here? i can't find any prompts and have read the help section to no avail... Jim, to add photos you simply need to switch from Mobile mode to Desktop mode (see bottom right corner of screen). This will turn open up a new option to add attachments to your posts. The only other thing to be aware of is a size limit of 2Mb per attachment - the upload will fail and tell you if the pic is too big - in which case you need to compress the image and then attach. Make sense?
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Post by jim on Jul 31, 2023 19:33:39 GMT 12
Thanks Fogg - sorted now
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Post by jim on Jul 31, 2023 19:53:18 GMT 12
actually , zooming in on those clamps i should have much bigger radius's on the corners and inboard faces... if needed by anyone i could make up more to suit.
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Post by Fogg on Aug 1, 2023 17:25:53 GMT 12
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Post by Fogg on Aug 1, 2023 17:27:26 GMT 12
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Post by sabre on Aug 1, 2023 21:27:22 GMT 12
Those bimini fittings are a good idea.
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Post by Fogg on Aug 2, 2023 8:02:37 GMT 12
Of course remember the potential hazards if attaching a/s to aluminium uninsulated. We put the whole thing together then realised we’d forgotten the nylon washers. So that’s was a couple more hours and a few beers to reassemble with those 🙄
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Post by sloopjohnb on Aug 2, 2023 8:37:54 GMT 12
come on Fogg......a few beers, by who's calculator?
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Post by Fogg on Aug 2, 2023 9:18:33 GMT 12
Sounds about right 😊
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