Hi. I'm in the design/ planning phase on about 1,000 watts of 12 volt panels going on the roof of my fifth wheel. Because of the array wattage, I'm going MPPT on the controller. I'm comparing the Midnite Classic 150 (96 amp) to 2 stacked Morningstar TS 45s (combined 80 amp). The classic is looking like less money and less phantom draw, even with the fan, but still not finished.
Since I'm going MPPT due to project creep (400 watts to nearly 1,000 now), should I be considering higher voltage panels (e.g., going up from 12V to 24V), as a general design parameter? Seems like 24V would reduce wire size (I'm designing to 2% to the controller, 1% thereafter), and lower the amp requirements on the controller.
I'm trying to price 24V panels that are at least 160 watts each and can't find many.
What 24V panels make sense for RVs?
Thanks
Bill and Linda said
11:56 AM Feb 27, 2016
John:
I appreciate your comment about "project creep." Guilty as charged. :)
Let me just cut to the chase and suggest you contact AM Solar for an opinion. http://amsolar.com/
Call them, don't just go by the website. 541-726-1091 They are knowledgeable and helpful.
I think these two sources will be more than helpful.
Bill
Dranoel said
03:29 AM Feb 29, 2016
I just installed 6 100 watt panels and a Tristar 45 MPPT. I used 3 strings of 2 panels each in series. That boosted my voltage from 19 to 38 to reduce current drop and take better advantage of the MPPT.
Bill and Linda said
08:21 AM Feb 29, 2016
A comment about the Tri-Star 45 controller - By design these controllers "welcome" more panels with higher watts than the 45 amp design. For 12 volt batteries the TS-MPPT-45 is designed for 600 watts worth of output. However, they are also designed to accept more than 600 watts worth of panel "rating" but will only "use" up to 600 watts. So, like I have, with 720 watts worth of panels feeding the "45" controller I get closer to 600 watts worth of charging more of the day due to the extra panels.
Recall one will, in reality, never get all the output of the panel's rating. Therefore "over sizing" this particular controller will effect more charging. To restate, the TS-MPPT-45 is specifically designed to have "over sized" panels feed it and will protect itself if excessive wattage is coming from the panels. It just doesn't use that extra wattage." This is not true of all controllers. My comments are specific to the TS-MPPT-45 unit. (The TS-MPPT-60 is the same as to design.)
On Edit I wanted to add in case you were not aware, there is a nice remote read out panel - TS-M-2 - that provides a nice read out of all the how - goes -it and diagnostic information for the Tri-Star. Comes with the connecting cable, connectors included. A nice addition IMO.
-- Edited by Bill and Linda on Monday 29th of February 2016 04:09:56 PM
bjoyce said
08:55 AM Feb 29, 2016
A side comment: Do the Morningstar controllers still require using an old Windows machine with a USB to serial adapter to custom configure them? I ask this, since many batteries now require custom settings for optimal charging.
Bill and Linda said
03:06 PM Feb 29, 2016
bjoyce wrote:
A side comment: Do the Morningstar controllers still require using an old Windows machine with a USB to serial adapter to custom configure them? I ask this, since many batteries now require custom settings for optimal charging.
I don't know how "old" a computer it has to be but if you want to do some micro settings it requires a serial port. However, most nominal settings are dip switch controlled.
That said, when I bought mine from AM solar I had them set it to match specifically the charge numbers available on my Magnum Inverter/Charger for the Lifeline AGM batteries such that both "chargers" were charging the same. The dip switch setting were really close to the Magnum's but because I could get it configured to perfectly match I did and that way I didn't have to make up a serial cable.
With the 60amp version it is controllable via a network / Ethernet cable. I just didn't need 60 amps and the 45 was more efficient for the available roof space / watts I had for panels.
Hi. I'm in the design/ planning phase on about 1,000 watts of 12 volt panels going on the roof of my fifth wheel. Because of the array wattage, I'm going MPPT on the controller. I'm comparing the Midnite Classic 150 (96 amp) to 2 stacked Morningstar TS 45s (combined 80 amp). The classic is looking like less money and less phantom draw, even with the fan, but still not finished.
Since I'm going MPPT due to project creep (400 watts to nearly 1,000 now), should I be considering higher voltage panels (e.g., going up from 12V to 24V), as a general design parameter? Seems like 24V would reduce wire size (I'm designing to 2% to the controller, 1% thereafter), and lower the amp requirements on the controller.
I'm trying to price 24V panels that are at least 160 watts each and can't find many.
What 24V panels make sense for RVs?
Thanks
John:
I appreciate your comment about "project creep." Guilty as charged. :)
Let me just cut to the chase and suggest you contact AM Solar for an opinion. http://amsolar.com/
Call them, don't just go by the website. 541-726-1091 They are knowledgeable and helpful.
Another excellent source of information more general but accurate information: http://www.jackdanmayer.com/rv_electrical_and_solar.htm
I think these two sources will be more than helpful.
Bill
A comment about the Tri-Star 45 controller - By design these controllers "welcome" more panels with higher watts than the 45 amp design. For 12 volt batteries the TS-MPPT-45 is designed for 600 watts worth of output. However, they are also designed to accept more than 600 watts worth of panel "rating" but will only "use" up to 600 watts. So, like I have, with 720 watts worth of panels feeding the "45" controller I get closer to 600 watts worth of charging more of the day due to the extra panels.
Recall one will, in reality, never get all the output of the panel's rating. Therefore "over sizing" this particular controller will effect more charging. To restate, the TS-MPPT-45 is specifically designed to have "over sized" panels feed it and will protect itself if excessive wattage is coming from the panels. It just doesn't use that extra wattage." This is not true of all controllers. My comments are specific to the TS-MPPT-45 unit. (The TS-MPPT-60 is the same as to design.)
This document might be helpful in your design:
http://www.morningstarcorp.com/wp-content/uploads/2014/02/MPPT-Technology-Primer.pdf
Bill
On Edit I wanted to add in case you were not aware, there is a nice remote read out panel - TS-M-2 - that provides a nice read out of all the how - goes -it and diagnostic information for the Tri-Star. Comes with the connecting cable, connectors included. A nice addition IMO.
-- Edited by Bill and Linda on Monday 29th of February 2016 04:09:56 PM
I don't know how "old" a computer it has to be but if you want to do some micro settings it requires a serial port. However, most nominal settings are dip switch controlled.
That said, when I bought mine from AM solar I had them set it to match specifically the charge numbers available on my Magnum Inverter/Charger for the Lifeline AGM batteries such that both "chargers" were charging the same. The dip switch setting were really close to the Magnum's but because I could get it configured to perfectly match I did and that way I didn't have to make up a serial cable.
With the 60amp version it is controllable via a network / Ethernet cable. I just didn't need 60 amps and the 45 was more efficient for the available roof space / watts I had for panels.