What Solar Panels to Buy

Discussion about any electrical topic except 240 volts. Solar, converters, inverters, lights, battery chargers, etc
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T1 Terry
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Re: What Solar Panels to Buy

Post by T1 Terry »

Where are you located at the moment Warren?
I would recommend a 150/50 Victron Smart MPPT controller but you will also need to replace the Victron BMV 700 (if you have one) with a Victron 712 BMV. This is because the Smart Victron system talk to each other via Bluetooth so the BMV tells the solar controller what the true battery voltage is and this gives much better solar output. The other bonus is both the solar controller and BMV can be viewed on a smart phone, so no need to check gauges any more.
Connect the panels in 2 x 6 panel series strings, a Noark 40 amp DC circuit breaker, so you can turn the solar off if required so you can work on the system, from there to the Victron 150/50 and 6 B&S cable, a 60 amp midi fuse in the positive cable and on to the rest of the electrical system, the negative to the load side of the 712 BMV shunt.
We buy our solar panels from a wholesaler and the sticker says "solar module" so that's not a lot of help, but we also fit ones with atempower stickers on them and they seem to be ok as well. We also looked at some slimline panels at a solar place in Sheparton that looked promising to give better clearance beside air conditioners and hatches to avoid shading. Margaret took a photo of the panel label so I'll have to find out what brand they were ....
We mount them using 70mm x 25mm x 1.6mm aluminium angle, rivnuts in the panel and 6mm stainless bolts through the angle and the 25mm angle glued to the roof using Selleys Armourflex .... 2 panels per set up because that's just easier to handle, take the plastic covers off the MC4 connectors so you can fully engage them together and solder the join, slide a bit of heat-shrink over the join to protect it and you can put the possible problems of a bad connection out of mind when trying to sort problems if they ever come up.
Don't forget the diodes in the positive cables at the end of each series string.

Sorry, long post, should have warned you to get a coffee first :lol:

T1 Terry
A person may fail many times, they only become a failure when they blame someone else John Burrows
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WarrenK
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Re: What Solar Panels to Buy

Post by WarrenK »

Again thank you for this information. I am in SE Qld. Just need the controller and circuit breaker as I already have the BMV712 in the caravan and fuse and cable accumulated over the years. Currently my panels are glued to a 25x25 mm frame attached to sides and middle of the caravan, so I might be able to install a frame on the panels and glue the panels to the frame on the caravan as they are around the same size as the ones I am going to remove. The diodes that are required, are ther specfic ones that should be used?
Thanks again,
Warren
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T1 Terry
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Re: What Solar Panels to Buy

Post by T1 Terry »

WarrenK wrote: Sat May 28, 2022 9:47 am Again thank you for this information. I am in SE Qld. Just need the controller and circuit breaker as I already have the BMV712 in the caravan and fuse and cable accumulated over the years. Currently my panels are glued to a 25x25 mm frame attached to sides and middle of the caravan, so I might be able to install a frame on the panels and glue the panels to the frame on the caravan as they are around the same size as the ones I am going to remove. The diodes that are required, are ther specfic ones that should be used?
Thanks again,
Warren
Schottky diodes so the voltage drop across the junction does't generate as much heat. The current is only around 3 amps or so, but the voltage is up to 130vdc plus ..... although they would only see that much back voltage (reverse bias I think it's called) if all 6 panels were shaded in that string yet none in the other string ..... We have a heap of these https://www.phippselectronics.com/produ ... 4EQAvD_BwE that we use on smaller strings or multiple rooftop solar panels linked in parallel, if you send us a mailing address we can send you some .... we had to buy them in lots of 500 so we still have quite a few left :lol:

T1 Terry
A person may fail many times, they only become a failure when they blame someone else John Burrows
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves

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