Forum Discussion

Talshion's avatar
Talshion
Explorer
Sep 25, 2020

2016 ITASCA TRIBUTE 31C Solar Upgrade

I am looking to add solar to the RV. It have a Residential Refrigerator in it that being ran off 3 Lead acid battery's at 300ApH. These last about 8 to 12 hours at best. I am replacing them with two lithium battery's at 200aph and adding one more in a few months for 300aph total.

I want to add solar but I'm not sure what I am needing. Since my system already has a 2000w inverter/charger in it that works with the generator and when driving.

I do not want to over charge the new battery's. Do I only need to get a Controller and a few Panels plus wiring.?

So is it as simple as running Solar Panels to a MPPT Charge Controllers directly to battery's. Is it really that simple?

Am I overthinking it or am I missing something.?

Thanks for the help.
Class A
  • Lwiddis's avatar
    Lwiddis
    Explorer II
    Sep 25, 2020
    Generally, you need one solar watt per battery amp hour but living in Washington you may need 1.5 or 1.75 watts per amp hour. Have you consulted a solar wiring chart to determine proper wiring? I use 10 gauge from the panels to the combiner box, 8 from the box to the controller and 6 from the controller to the batteries but my 3 panels are in parallel. Wiring distance is important too...longer the distance the bigger the wire. Don't limit any future additional panels by using small wire. Consider doing your panels in series too. The controller you buy needs to specifically say it works with lithium batteries. You'll love not needing a generator! Seems your current fridge is a power hog.
  • RLS7201's avatar
    RLS7201
    Explorer II
    Sep 25, 2020
    Just make sure that your MPPT controller is configurable for Li batteries. It's my understanding that your new MPPT controller will need to be able to stay at 14.4 volts until the Li batteries are full. Then either the MPPT controller will shut off or the controller built into the batteries will stop the charge.
    You can't have too much solar. I like 24 volt panels. They are cheaper and allow smaller wire. Over size your MPPT controller, just incase you decide on more panels.


    Richard
  • Talshion's avatar
    Talshion
    Explorer
    Sep 25, 2020
    RLS7201 wrote:
    Just make sure that your MPPT controller is configurable for Li batteries. It's my understanding that your new MPPT controller will need to be able to stay at 14.4 volts until the Li batteries are full. Then either the MPPT controller will shut off or the controller built into the batteries will stop the charge.
    You can't have too much solar. I like 24 volt panels. They are cheaper and allow smaller wire. Over size your MPPT controller, just incase you decide on more panels.


    Richard
    Thank for you info on that. Was looking to do that.

    Glad it is that simple.

    Any reviews on MPPT controllers?
  • 2oldman's avatar
    2oldman
    Explorer II
    Sep 25, 2020
    Talshion wrote:
    Any reviews on MPPT controllers?
    Just make sure you get one that's configurable for Li batteries. ie.. correct voltage, no absorb..etc. And one that will handle the solar amps you expect to harvest.

    Outback makes top of the line.

    Just a friendly correction.. it's ah, not aph
  • Talshion's avatar
    Talshion
    Explorer
    Sep 25, 2020
    2oldman wrote:
    It's that simple.


    Glad it that simple. Makes my like simpler.

    Does anyone know a place for good deals on Panels and controllers?
  • 2oldman's avatar
    2oldman
    Explorer II
    Sep 25, 2020
    Arizona wind and sun is a good, reputable place. Don't hesitate to pay a bit more for service after the sale.
  • pianotuna's avatar
    pianotuna
    Nomad III
    Sep 25, 2020
    Consider Victron for the controller (Outback is good too)

    I'll be going to SiO2 jars next summer as they can be run stone bone dead with no damage, unlike most other batteries.
  • Talshion's avatar
    Talshion
    Explorer
    Sep 26, 2020
    Thanks eveyone for all the info. It helpful.

    The wiring I can handle. The brand of controller and brands for the Solar panels I know nothing about. I like having reviews but I not a big fan of reviews on the company website. When I see 150 like's and no one saying I have a issue or these are just SO/SO. I tend to have a raised eyebrow.

    Of the two controllers mentioned, what's the pro and cons for them. What made you go with one or the other?

    Outback Vs. Victron

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