Starting out

Redford
Redford Solar Expert Posts: 38 ✭✭
So at the end of this week I will be in a position to start putting together my solar system.

I am going to start out with a Flexmate 80 charge controller and one Evergreen Es190. I am also going to splurge and get the Flexnet DC battery monitor.

I already have two 120 ah batteries that are in good shape. I have minimal loads as of now, but of course they will increase in time which will allow me to get more panels.

I was wondering if the battery monitor is needed with the network communications and status information that the FM 80 has. Also the ES190 will put out >7 amps max, is there any minimum 12v input that the FM 80 would need to properly operate? (I have to go with the FM80 to work when the system is rewired for 24v and the current will double)

In time, I would like to have a total of 5 ES190's and have read that sometimes if a panel is discontinued, there could be problems wiring other panels in the system. I don't see the evergreen company going away anytime soon but if I buy one or two ES190's then they are no longer made, could I put ES180's or ever 195's in the string? When I get more panels I am going to wire the array for 24v, but i will have to start with 12v.

Also as far as wiring goes, I know that I need a shunt for the Flexnet DC monitor. Would there be any other suggestions of extra items I would need to wire this all up? I have a 100amp DC load center already configured with an inline disconnect?

I thank you in advance for reading and helping!

Comments

  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Starting out

    Not really to answer your questions, but an observation.

    Be advised that your battery bank seems quite small. Remember that batteries should never be drained more than 50% and ideal no more than 20%. Also adding new batteries to an old battery bank will serve to "age" the new batteries to the effective age of the old. Battery banks should be generally the same size, configuration, and age. Consider starting with more batteries if you are going to increase you PV capacity soon. As for discontinued panel wiring, as I understand it, wiring new panels should not be a real problem assuming they are SIMILAR in voltage and amperage. BB or SG or someone with more experiance will weigh in.

    Good luck

    Icarus
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Starting out

    The Flexmax is WAY oversized for this configuration, I would be surpised if a cheap pwm controller wouldn't get better harvest as the Flexmax has a large tar loss realitive to this small configuration.

    A MorningStar Sunaver Mppt is good for one of these evergreens, or two if your running 24V and will out harvest the Flexmax for sure.

    For the cost of the Flexmax, you can have 3 of the MorningStars and handle 6 of the evergreens at 24V and can add, when and IF you ever buy more panels, heck, for the price of the Flexmax, you can have another 50-75 watts of solar for the cost difference on the charger controllers

    To be clear, I'm not knocking the Flexmax, its just its an 80 amp, 4kW charge controller and you connecting a 190w solar panel to it. Not a good match
  • Redford
    Redford Solar Expert Posts: 38 ✭✭
    Re: Starting out

    The batteries I have don't have the capacity to run a whole lot. Right now they run two alpendglow lights which are 9 watts a piece and a sattelite radio. About an hour or two a week they power a small TV that registers at about 60 watts.

    When I can afford a better battery bank I would like to shoot for four 4D AGM's and shoot for about 800 ah of capacity. As of now all I have to work with is about 200 ah of reserve.
    I think what I have to work out in they future is if my percent charge will be too high as I purchase panels.

    I was afraid that the FM80 was (initially) too large a controller. By going with the larger controller, I was hoping to accommodate for future solar expansion. If I get 4 ES190's @ 24v, charging at 7 amps a piece, that would be around 60 amps going to the controller not accounting for mppt boost which would max out an mx60.

    Honestly though, if it's cheaper (initially) to go with a 15 or 20 amp charge controller that would be fine for me. I just finished building (framing and finishing) my house and although I don't owe any money on it I don't have a lot to be throwing around!
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Starting out

    Split the difference, buy a cheap pwm controller on E-bay for now, keep the flexmax for later. Then re-sell the cheap one.

    So your daily load would be something in the neighborhood of 1.5 amps for the lights, .5 amps for the radio? (My sirius draws almost an amp @ 12vdc!) all for perhaps 6 hours? Equals 12amp/hour day. Toss in 7 hours of TV per week, adds about 1 more amp/hour day, making ~13. If your battery capacity is ~200 ah you will be ~7% of capacity, well within range. 180 watt panel would put out ~14 amps, over a 4 hour charge window, you should get pretty close on a daily basis.

    Even with the ineficiencies our your controller I think you still would make out OK. I have 210 watts of panel, and draw ~30ah/day net and almost always get it back. Beware however of growing loads. I started with just 1 light and the fridge igniter, and now have, lights, radio, internet reciever and modem, laptops, water pumps, ceiling fans etc. So many things I couldn't imagine 15 years ago.


    Icarus
  • Redford
    Redford Solar Expert Posts: 38 ✭✭
    Re: Starting out

    I'm where you were 15 years ago! Except I have a EU3000 which I run to use power tools and charging right now.

    It was alright when fuel was 2.00 a gallon, but now it's definitely not acceptable to run it if I'm not working on the house.

    A bit off topic, but I found a guy that sells wireless remote starters for honda EU series generators. It works well and is pretty easy to install.
  • blwncrewchief
    blwncrewchief Registered Users Posts: 17
    Re: Starting out

    SG has the better technical details on the charge controllers but from my testing with the FlexMax80's they seem to work fine. I have tested mine with just one of my Evergreen 180's and saw sustained output over stc on a 60 degree day. So I don't doubt the tare loses but I don't see a pwm controller out performing it even with one panel. Plus with the Evergreens being 18v nominal panels you'll lose allot on a 12v system. Mine track about 27v on a cold 30 degree day and about 21v on a 80 degree day. If your already thinking about 5 190w panels I would go ahead for the FM80 or another larger MPPT controller. So far I give the FM80 a thumbs up. And I'm running them hard. Today on my 24v system I saw 2222w and 79.8a on my one with the 2kw array:D

    The FNDC is a great monitor and tool for a system. Just don't forget you need a hub and mate for the FNDC to be useful.

    Your at the point of starting to build a system so now is the time to really try to decide where you might go long term with this. This stuff is terribly addictive (just ask my and many peoples wallets here:roll:) so pick a good direction and equipment you like and can build on. If your already planning 5 190 panels your looking at building a very capable system. And I'll bet it will end up bigger then that. I would highly recommend in my personal opinion to pick a manufacturer and build a matching system.
  • Redford
    Redford Solar Expert Posts: 38 ✭✭
    Re: Starting out

    Right on, Eventually I would like to shoot for a low amperage high(er) voltage system, but starting with only one panel, I can't make that happen right now.

    So, say I go with the 195 evergreens and the MS sunsaver mppt controller.

    One panel @18v will work fine....when I acquire two panels and wire them @ 24v the system will be 390w and the limit the controller will handle is 15 amps. Would the mppt boost put the controller over the limit or does the boost happen downstream of the controller? Unless losses inherent in the system would make up for that. It seems like it's kinda close.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Starting out

    A well designed MPPT controller will limit its power output its maximum safe level of current--even if there are more solar panels available (and from all indications, the MorningStar MPPT is a well designed unit).

    What it cannot protect against is if the solar panels exceed its maximum safe operating voltage (typically Voc of the solar panels on a cold day)...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Redford
    Redford Solar Expert Posts: 38 ✭✭
    Re: Starting out

    At first, I don't expect 195w @12v of panel to effectively run the mppt on the controller as I take the mppt boost to take a higher voltage with a lower current to the opposite (lower voltage w/ a higher current)

    Being that an ES195 is 18v nominal.

    When I can afford a second panel we'll see how it operates in series.