John Frum
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If your summarize your 24 volt system I will make an 12 volt version.
Travel Trailer 24v LiFePo4 / Solar / Charger / Inverter system setup...
- Thread starter CanadianEH
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There should be a set of common bus bars in your system where the loads all connect into. The batteries will also connect into these bus bars. The two MPPT solar charge controllers would also tie into the same common bus bars. Once you connect the two solar charge controllers to the common bus bars, you're done. They will both work.
CanadianEH
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so its ok to have 2 controllers hook up through a bus bar? they wont feed back each other or anything?
What happens if one of the panels is shaded and that controller turns off?
CanadianEH
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I believe that info is all in my first post of this thread?
Yep. Works fine. I have two controllers feeding into my LiFePO4 battery bank. I've had one set of panels partially shaded, while the other set was in full sun. No big deal.
Some good points for a 12 volt system there. Is Sterling Power the only maker of a 12 to 24 volt DC to DC Charger? My 12 volt loads are minimal and I already have a 24 volt inverter and 24 volt battery otherwise I’d likely go with a 12 volt system. .
Victron has a few 12v-24v chargers, in various amp ratings. I can't speak to other brands.
Sounds like you are sorting it out, but I wanted to comment as I recently did a fairly large rewiring of my smaller TT with a 12V system and a MP Solar all in one (1012lv I believe).
When I wired things, I wanted to not mess around with certain outlets not working depending if I was on shore power, etc. So, other than the Microwave and AC unit, the rest of the panel runs off the inverter. This is fine, but it means you cannot plug anything over 1000W into any outlet, regardless of whether you are plugged into the pedestal (obviously). This is SO DAMNED frustrating. Instant pot? over 1K watts. Tiny nespresso machine? Over 1K. I ended up having to wire in some additional outlets that bypass the inverter.
Honestly, if I did it again, I would not have done the all-in-one, although that is the ONLY complaint I have.
When I wired things, I wanted to not mess around with certain outlets not working depending if I was on shore power, etc. So, other than the Microwave and AC unit, the rest of the panel runs off the inverter. This is fine, but it means you cannot plug anything over 1000W into any outlet, regardless of whether you are plugged into the pedestal (obviously). This is SO DAMNED frustrating. Instant pot? over 1K watts. Tiny nespresso machine? Over 1K. I ended up having to wire in some additional outlets that bypass the inverter.
Honestly, if I did it again, I would not have done the all-in-one, although that is the ONLY complaint I have.
CanadianEH
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Could you not have used a larger all in one units. Like those growatt 3000 systems. Seems that would solve your problem of not being limited to 1000 watts. They seem to be an excellent solution for a budget conscious builder.
Yup, but was limited on space, and wanted to stick with 12V. I don't think they make 12V 3K inverters.
We just make do now. Too lazy to mess with it. The camper is parked on some land we bought and we plan to build a pole shed with an outdoor kitchen, so a lot of this won't be such a big deal going forward. More of a minor annoyance.
the_colorist
"Move over... let me fix it" Installer/Engineer
1. IMHO the biggest issue I see with the Growatt's inverters would be real-world efficiency at low wattages (besides other things). It's a bit low IMHO. On a large system with excess PV and batteries it's probably not that big of a deal. On a small system though, every watt counts. Sizing is also more critical, even with high-eff inverters. The larger they are, the more inefficient they are at lower wattages. Without AC, most of the time I'm guessing you'll be using 200W on average? Probably less? If so and you see no possibility of running more than 1600W continuously then the 2000VA Multiplus is usually a good choice.
2. Victron MSRP/retail is expensive. Unless you know an installer/dealer like me or someone else who is willing to work out a discount.
Feel free to PM me if you want a quote.
3. You'll save power if you can switch to a BMS that uses an external latching contactor. Those FET's burn power. It's been tossed back and forth but IMHO if you can use a BMS that has both Victron CAN comms and uses a latching contactor, you'll save a bit of power. Plus your cells will likely last longer/capacity will probably fade slower.
4. If you use Victron, you have the option of using microinverters (per panel input) or string inverter such as a SolarEdge with optimizers. Either option will ensure you get the most power out of your panels at all times due to the per-panel tracking.
There have been some good deals on SolarEdge inverters/optimizers lately on eBay. Anything HDWave should be fine.
5. I would need to check on the shipping costs but if you're interested I could have some 350W REC TwinPeak 2S 72 Series (144-Half Cell) shipped up to you for $95 ea (before shipping). They are new off of a commercial install but never operated (as I recall, have to check the warehouse). As such they only have a 1-year warranty.
We also have some Phono 370W PS370M-24/T panels for $130 ea (before shipping). Full 25-year warranty.
Datasheets for both attached.
They aren't as large for sure but if you have the space could save you some $$$.
2. Victron MSRP/retail is expensive. Unless you know an installer/dealer like me or someone else who is willing to work out a discount.
Feel free to PM me if you want a quote.3. You'll save power if you can switch to a BMS that uses an external latching contactor. Those FET's burn power. It's been tossed back and forth but IMHO if you can use a BMS that has both Victron CAN comms and uses a latching contactor, you'll save a bit of power. Plus your cells will likely last longer/capacity will probably fade slower.
4. If you use Victron, you have the option of using microinverters (per panel input) or string inverter such as a SolarEdge with optimizers. Either option will ensure you get the most power out of your panels at all times due to the per-panel tracking.
There have been some good deals on SolarEdge inverters/optimizers lately on eBay. Anything HDWave should be fine.
5. I would need to check on the shipping costs but if you're interested I could have some 350W REC TwinPeak 2S 72 Series (144-Half Cell) shipped up to you for $95 ea (before shipping). They are new off of a commercial install but never operated (as I recall, have to check the warehouse). As such they only have a 1-year warranty.
We also have some Phono 370W PS370M-24/T panels for $130 ea (before shipping). Full 25-year warranty.
Datasheets for both attached.
They aren't as large for sure but if you have the space could save you some $$$.
CanadianEH
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Hey thanks for all the Info. I do appreciate your response and offers!1. IMHO the biggest issue I see with the Growatt's inverters would be real-world efficiency at low wattages (besides other things). It's a bit low IMHO. On a large system with excess PV and batteries it's probably not that big of a deal. On a small system though, every watt counts. Sizing is also more critical, even with high-eff inverters. The larger they are, the more inefficient they are at lower wattages. Without AC, most of the time I'm guessing you'll be using 200W on average? Probably less? If so and you see no possibility of running more than 1600W continuously then the 2000VA Multiplus is usually a good choice.
2. Victron MSRP/retail is expensive. Unless you know an installer/dealer like me or someone else who is willing to work out a discount.
3. You'll save power if you can switch to a BMS that uses an external latching contactor. Those FET's burn power. It's been tossed back and forth but IMHO if you can use a BMS that has both Victron CAN comms and uses a latching contactor, you'll save a bit of power. Plus your cells will likely last longer/capacity will probably fade slower.
4. If you use Victron, you have the option of using microinverters (per panel input) or string inverter such as a SolarEdge with optimizers. Either option will ensure you get the most power out of your panels at all times due to the per-panel tracking
There have been some good deals on SolarEdge inverters/optimizers lately on eBay. Anything HDWave should be fine.
5. I would need to check on the shipping costs but if you're interested I could have some 350W REC TwinPeak 2S 72 Series (144-Half Cell) shipped up to you for $95 ea (before shipping). They are new off of a commercial install but never operated (as I recall, have to check the warehouse). As such they only have a 1-year warranty.
We also have some Phono 370W PS370M-24/T panels for $130 ea (before shipping). Full 25-year warranty.
Datasheets for both attached.
They aren't as large for sure but if you have the space could save you some $$$.
1. I have been honestly been deeply considering the growatt as a good all around solution for my situation. Likely the 24v 3000. I really like the simplicity. And at the cost it seems almost like a no brainer. I feel ill have power to spare. I'll have large battery capacity. And with 2 x 800 panels I should easily be able to cover my daily use.
2.ill pm you.. ??
3.ill have to read more About this as I'm not totally sure I understand the benefits vs Cost.
4.is this worth it for 2 Panels? Or just complicating things?
5. where are you shipping up from? I am guessing once I convert USD to Cad and add shipping, it would be prohibitively expensive. Those 400w peak duo q cells I can get are in Canadian dollars, walk in, pick up and drive home with Full warranty.
CanadianEH
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Ok.. finally had a chance to get proper measurements and do a sketchup mock up.
The front of the trailer is to the left. A few items I guess on the height. But it is likely pretty accurate. The roof vent in between the 2 panels is the roof vent in our bedroom. We never open it and have a insulated pillow stuffed in it.
The front of the trailer is to the left. A few items I guess on the height. But it is likely pretty accurate. The roof vent in between the 2 panels is the roof vent in our bedroom. We never open it and have a insulated pillow stuffed in it.
Looks great! I have the same vent in my "bedroom" with an insulating pillow in it. I hardly ever open the vent. It looks like a couple of smaller panels would fit at the front, on either side of the vent.
At one point, I was so frustrated with the layout, I considered ripping out my TV antenna. I never use it, so it wouldn't have been missed. But that was when I was trying to fit four 200 watt panels, which wasn't going to work no matter what I did. The pair of 320 watt panels ended up being an ideal fit, once I removed the useless roof rack.
At one point, I was so frustrated with the layout, I considered ripping out my TV antenna. I never use it, so it wouldn't have been missed. But that was when I was trying to fit four 200 watt panels, which wasn't going to work no matter what I did. The pair of 320 watt panels ended up being an ideal fit, once I removed the useless roof rack.
orangeminnie
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If the battery has a BMS, it would disconnect before destroying the battery. Also, the brakes only pull a few amps - much less than I would have guessed. If a trailer gets loose, there are many other things that could break that would be more concerning.
CanadianEH
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One more 400 watt would fit between the front roof vents as there is a 42"+ gap there and the panels are 39" wide... but honestly I dont think I need more than 800 watts. especially with a 310ah 24v battery bank. at least I know know that I can fit more if required later on.
The thing I am not sure if it is an issue or not for wind... I have a slightly curved roof. Yet the panel at the back would be sitting like the following picture. now this is quite exaggerated I dont believe the curve of the roof is this much.. I did this just to illustrate the curve with the flat solar panel at the back of the trailer.
Assuming you use standard z brackets, if you use only four brackets, the curve won't matter at all. If you use six brackets, the middle set will be a problem. But there are ways around that. Mount the end brackets on the bottom of the frame rail and the middle brackets on the top (inside) of the frame rail. That may be enough of a difference to handle the curve.
CanadianEH
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Sorry I should have clarified.. not worried so much about mounting it.. worried about the wind speed increasing under the middle of the panel where it narrows form the curve of the roof, casuing panel flex towards the middle.
I suppose for that one a wind dam would be the best course of action.
A set of brackets in the middle is less complicated (in my opinion) and provides 50% more security.
An air dam would have to be secured to both the panel and the roof.
CanadianEH
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Here is a quick idea of the system I am leaning towards.. thoughts? I could use some help on where to put fuses/breakers and what size.
Also I ordered a 100A JDB 8s 24v bms ( thinking I was doing separate components. with a 2000w inverter). The growatt is a 3000w inverter I believe the math shows I should have likely gone to a 150a bms. I cannot see myself use anywhere close to 3000w. Is there a way to limit the growatt inverter to 2000w or should I order another BMS in the 150A size.
Thanks!
Also I ordered a 100A JDB 8s 24v bms ( thinking I was doing separate components. with a 2000w inverter). The growatt is a 3000w inverter I believe the math shows I should have likely gone to a 150a bms. I cannot see myself use anywhere close to 3000w. Is there a way to limit the growatt inverter to 2000w or should I order another BMS in the 150A size.
Thanks!
I haven't looked at the specs for the higher amp JBD BMS. I think I recall reading that it didn't have the same feature set as the 100 amp. That may be why Overkill Solar doesn't carry it.
Those Blue Sea battery disconnect switches are going to add a lot of cost to your project. The top right one is expected. The bottom right should be a circuit breaker. The left switch, I'm thinking isn't right, but I'm not sure if any switch/breaker is necessary there at all. If you want to turn off the AC part of the system you would flip all the AC breakers in the panel.
Those Blue Sea battery disconnect switches are going to add a lot of cost to your project. The top right one is expected. The bottom right should be a circuit breaker. The left switch, I'm thinking isn't right, but I'm not sure if any switch/breaker is necessary there at all. If you want to turn off the AC part of the system you would flip all the AC breakers in the panel.
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