New temporary install - where and what to measure

TenMileTenMile Solar Expert Posts: 62 ✭✭
Hey all,

In the middle of doing a new off-grid solar install at a family cabin. Given that the cabin is remote, I have temporarily set the system up in my backyard so that I can understand how it works, and to make sure I have all the pieces and parts required before doing the permanent installation.

System consists of the following:

3 x 125W, 7.1Amp panels wired in parallel
1 x Morningstar TriStar-45 PWM charge controller with remote meter
1 x GoPower 2000Watt Pure Sinewave inverter with remote meter
2 x Trojan T105 batteries wired in series for 12V, 225Ah
Assorted fuses and breakers

System will be installed at the cabin as follows:

Panels (side of pole mount) --> DC Switch -->80ft #2AWG Cable --> DC Switch --> Fuse --> TriStar --> Fuse --> Battery --> DC Switch --> Inverter --> AC Panel

I read HandyBob's great blog and tweaked the TriStar's settings so it's providing the batteries 14.8V. Runs from the Tristar to Battery to Inverter are all using #2AWG welding cable -- nothing longer than 6ft.

The temporary install follows the same setup as above and has now been running for roughly 36 hours. Yesterday (day 1) was mostly cloudy but the sun came out late afternoon and I generated 30Ah.

I believe I have everything optimized -- but this is my first installation. Looking for advice as to what I should be measuring and monitoring now before I take the system to the cabin in roughly 1 month. I will be doing the Firmware update on the TriStar and Remote Monitor tonight to enable logging and recording of data. Is it worth measuring the amperage along the system to see what cable losses are, or will the logging provide that sort of guidance?

Anyhow, feel free to tweak the design -- components are locked in and purchased, but I am willing to add more breakers, fuses etc if they are warranted...

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: New temporary install - where and what to measure

    My advice would be to get a hydrometer and check the Specific Gravity of each battery cell regularly. If they are staying charged, that's good. Also monitor the electrolyte level in the cells. If they are using too much water, lower that Absorb Voltage down towards 14.2 Volts.
  • dwhdwh Solar Expert Posts: 1,341 ✭✭✭
    Re: New temporary install - where and what to measure

    Fuse between battery and inverter?

    EDIT: And how often do you plan to be there to check the water levels? HandyBob's settings will likely use more water than normal settings.
  • TenMileTenMile Solar Expert Posts: 62 ✭✭
    Re: New temporary install - where and what to measure

    How often would you recommend checking the battery levels? During spring and summer we're always there. Fall and winter, not so much. Is this a weekly or monthly maintenance routine -- more or less? Trojan recommends checking them once per month until you see how thirsty they are. Maybe run the Tristar at 14.8V when we are using it heavy, and then set it back to 14.4V in the Fall?

    Had my first system fault today -- which HandyBob warned about. I have a GoPower 2000W inverter and the Over-voltage protection kicked in as the batteries were up to 15.2V. I was charging the system with basically no load on the inverter. The OVP protection may in fact force me to set the system back to 14.4V as I don't want to cause system alarms when grandma is up there alone.

    Today's testing day was primarily sunny with some scattered cloud. Produced 92Ah from about 8am to 4pm.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: New temporary install - where and what to measure

    Have you got a remote temperature sensor for that Tristar? http://www.solar-electric.com/prosremtempr.html A very worthwhile addition.
    I'd check the water once a week to start with. make sure it stays at least 1/8 to 1/4 inch over the plates.
    You don't need to change the Absorb Voltage seasonally.
  • TenMileTenMile Solar Expert Posts: 62 ✭✭
    Re: New temporary install - where and what to measure

    Actually yes I do have the temp sensor -- failed to mention that and realized it after I made my post. I've also got the TriStar battery sense wires connected too.

    Where are you in BC Cariboocoot? I live in Victoria, cabin is on Lake Cowichan.
  • dwhdwh Solar Expert Posts: 1,341 ✭✭✭
    Re: New temporary install - where and what to measure
    TenMile wrote: »
    How often would you recommend checking the battery levels? During spring and summer we're always there. Fall and winter, not so much. Is this a weekly or monthly maintenance routine -- more or less? Trojan recommends checking them once per month until you see how thirsty they are. Maybe run the Tristar at 14.8V when we are using it heavy, and then set it back to 14.4V in the Fall?

    Yea...dunno. I've no experience using his settings. But since you'll be there you'll be able to get a feel for how much water you're using at the higher settings. At first I'd check weekly and see how it goes. You might want some Water Miser caps.

    Also there is the temperature compensation - the charger will adjust the voltage up if the batteries are cold, so in winter that might end up using more water. I'll have to leave it to the snowbirds around here to answer that one.

    Today's testing day was primarily sunny with some scattered cloud. Produced 92Ah from about 8am to 4pm.

    Nice!
  • mike95490mike95490 Solar Expert Posts: 7,225 ✭✭✭✭
    Re: New temporary install - where and what to measure
    I'd check the water once a week to start with. make sure it stays 1/8 to 1/4 inch over the plates.


    ?? I'd get real nervous if my water got down to 1/8" over the plates, I have about an inch between my plates, and the base of the split ring on the filler cap. I'd always thought to keep the level no fuller than contacting the split ring, and always above the plates, and I always keep it up to the split . Just in case I miss a month or two of water checking.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
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  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: New temporary install - where and what to measure

    Right you are Mike! It was supposed to say "at least 1/8 to 1/4 above the plates". I fixed it 'cause I don't want anything thinking the water level shouldn't be any higher!

    TenMile: I live near 100 Mile House. Except I'm not there just now.
  • Ralph DayRalph Day Solar Expert Posts: 871 ✭✭✭
    Re: New temporary install - where and what to measure

    Surrette batteries fill level is 1/4 to 1/2 inch below filler neck bottom. That leaves about 2 inches above the plates, lots of room for safety (in case you forget to check for a month or forget to cut back charge rate when not around).

    Sometimes it's tough to see the level until there's some disturbance in the electrolyte (your pouring of water or bubbles). You develop a technique over time.

    Electrolyte really expands when under heavy charge(eq). The level can rise 1/2 inch or more in my case.

    Ralph
  • SevenSeven Solar Expert Posts: 292 ✭✭✭✭✭✭
    Re: New temporary install - where and what to measure

    What voltage are the panels that you have?
  • TenMileTenMile Solar Expert Posts: 62 ✭✭
    Re: New temporary install - where and what to measure
    Leper wrote: »
    What voltage are the panels that you have?

    System is 3 x 12V (max 17V), 125W (each), 7A (each) wired in parallel.

    In peak sun I've seen the TriStar report performance up to and even in excess of the rated maximums for the panels ~ 390W and 25A.
  • Oscar13601Oscar13601 Registered Users Posts: 18
    Re: New temporary install - where and what to measure

    I have a question? The panels have to be 24V each if the system is 24V system? So, that being said, the panels, batt charger, batt bank and inverter has to be 24v. Is this correct???? Now, can i connect 2 12V panels to a 24V system????


    Thanks
  • westbranchwestbranch Solar Expert Posts: 4,812 ✭✭✭✭
    Re: New temporary install - where and what to measure

    Yes, 2 - 12 v panels in SERIES will produce 24 volts and the original Amps of 1 panel ( series = add volts, parallel = add Amps).
    Yes, you will need a 24 volt charger and a 24V inverter.
    Remember 12 V and 24 V are 'NOMINAL' panel ratings and the Vmp has to be ~= 17 V for a 12 v panels to be able to sharge the battery and ~34V to charge a 24 volt battery.

    hth
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge, Hughes1100 Sat Modem
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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