Which is something I considered. However, for prolonged deep winter weeks. I do have a gas powered geny running a 24v 40amp Iota charger with IQ4 attachment and additional IQ4 Li attachment incase I need it for the lithium bank.
Solar panels to bus bars
- Thread starter Aldricoak
- Start date
Current I use an Iota 24v 40amp charger running on a geny. However I have considered the set up you just have suggested to get away from gas. I my Flooded battery bank also has an attached 24v 30amp wind generator attached but I don't see much use from it as there isn't a lot of wind to sufficiently turn it for any length of time.
HarryN
Solar Enthusiast
Just to throw out another semi crazy idea, especially AGM banks need both current / power and time to charge.
One way to extend the "time" aspect is to have solar panels facing multiple directions - such as morning, "normal" and "very late afternoon".
The morning and late afternoon directions can end up being vertically mounted on a convenient wall.
Obviously the efficiency is less, but sometimes that can still be helpful.
I have not used them, but midnight controllers are supposed to be able to deal with multiple charge units in parallel.
Depending on the situation, poly panels can sometimes be useful in overcast lighting situations as they accept wider incoming angle light and scatter.
For the van installations that I use in this area (which is quite overcast in the winter), I have had good luck with poly panels combined with bogart PWM controllers. Most vans don't have room for a lot of panels so it can be tricky balancing the available space and achieving the minimum turn on voltage for an MPPT controller.
Roughly what is the string voltage of your solar array?
The reason that I ask is that some controllers require (V battery) + ( 5 to 10 volts) just to turn on, while a PWM controller it is more like just a 1 volt higher required.
One way to extend the "time" aspect is to have solar panels facing multiple directions - such as morning, "normal" and "very late afternoon".
The morning and late afternoon directions can end up being vertically mounted on a convenient wall.
Obviously the efficiency is less, but sometimes that can still be helpful.
I have not used them, but midnight controllers are supposed to be able to deal with multiple charge units in parallel.
Depending on the situation, poly panels can sometimes be useful in overcast lighting situations as they accept wider incoming angle light and scatter.
For the van installations that I use in this area (which is quite overcast in the winter), I have had good luck with poly panels combined with bogart PWM controllers. Most vans don't have room for a lot of panels so it can be tricky balancing the available space and achieving the minimum turn on voltage for an MPPT controller.
Roughly what is the string voltage of your solar array?
The reason that I ask is that some controllers require (V battery) + ( 5 to 10 volts) just to turn on, while a PWM controller it is more like just a 1 volt higher required.
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Funny enough your thinking about arrays facing east and west to catch the majority of rays is exactly what I am after arrays wise. Next week I start to work on this very issue. 6 panels (100w 22.56VOC 5.50Isc) East; 6 panels (100w 22.56VOC 6.56Isc) South; facing, 6 panels (100w 22.50VOC 5.50Isc) West. These fused arrays would feed into busbars, then fused (2) MPPT'S, feeding their own respective battery banks. Bank #1 Flooded; Bank#2 Li.
Basically, the bus bar set up is a collection point of energy to draw from for the mppt's.
Basically, the bus bar set up is a collection point of energy to draw from for the mppt's.
HarryN
Solar Enthusiast
It does not surprise me at all to be thinking this way.
The work space for my van electrical shop is just some storage units that I rent. There are no utilities of any kind, so it really is just like being completely off grid. It isn't ideal, but it works ok.
My vehicle has solar on top facing "up", so it can capture that power.
I have solar panels mounted on 2 test stands that I can move around and test various conditions, solar / battery combinations.
Customers like to mount their own solar panels (which is fine with me) but I can't really control what they will set up so I have to be able to deal with a variety of setups.
The smaller power systems that I build are 24 volt and the larger ones are 48 volt. Some are AGM and some are LiFe - mostly depending on the weather conditions that the vehicle will experience.
The power systems that I build are first built on a table, then tested using the "test stands" prior to installing in their van or shipping to them.
The "test stands" are just some good quality metal rack shelves on large wheels that I can face various directions as needed.
The blue panels are solarland poly, the black ones are solarland monos.
It does not always look this organized.
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As far as the bus bars, most off the shelf bus bars (like the blue sea ones) are rated for max 32 volts. Look at isolators as a way to deal with the higher voltages in the array. I can send some to you if that helps. Just send a pm to me.
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HarryN
Solar Enthusiast
I am not sure if sharing the solar array(s) for feeding into the dual solar charge controllers will work or not.
Equipment suppliers will probably discourage it but they are driven by how to be 100% sure that things will work "well and meet code compliance" vs "acceptably".
The lower risk approach would be to make them individual array sets for each battery bank.
As long as you are willing to experiment / adjust as needed, many things are possible.
Equipment suppliers will probably discourage it but they are driven by how to be 100% sure that things will work "well and meet code compliance" vs "acceptably".
The lower risk approach would be to make them individual array sets for each battery bank.
As long as you are willing to experiment / adjust as needed, many things are possible.
houseofancients
Solar Wizard
HarryN
Solar Enthusiast
Looking at your setup again, if it is Vmp ~ 36 volts like I am interpreting, in overcast weather, then I would use bogart PWM controller.
It will work in low light conditions when a lot of MPPTs won't.
The flip side - on a nice sunny day, the MPPT will work better.
They will self limit to 30 amps output - not sure about your other ones.
Have not ever tested running two in parallel from one array. Sounds interesting.
It will work in low light conditions when a lot of MPPTs won't.
The flip side - on a nice sunny day, the MPPT will work better.
They will self limit to 30 amps output - not sure about your other ones.
Have not ever tested running two in parallel from one array. Sounds interesting.
I will draw out the entire system this evening and post it. The Bus Bars I have are Mofees 48v 250amp these seem to work well and I have yet to feel heat on these while in action.
Neither would I and I didn't suggest that, never would. I was speaking in the generic.
Although it has been done, nothing I would try.
MajicDiver
Solar Enthusiast
I tried connecting one mppt input of both of my Growatt MIN-XH-US inverters to the same string back in late December- both inverters tripped in a second or so, quicker than I could see anything on the app or the VOM I was watching - nothing was damaged but I’ll never do it again. I expect what happens varies widely depending on the inverter model and how it operates and the various protection schemes that exist. By tripped I mean the ac output disconnected from the grid. Was not using the off grid output at the time.
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