Deep cycle batteries for cranking

I have a boat powered by a 350 Chev engine. I have two group 31 starting batteries entering their 11th season and figure it's time to replace them. I'm considering replacing them with two group 31 fla's that will be paralleled all of the time. Wondering if they will have enough oomph for cranking this engine. Has anyone tried something similar?
Island cottage solar system with 2500 watts of panels, 1kw facing southeast 1.3kw facing southwest 170watt ancient Arco's facing south. All panels in parallel for a 24 volt system. Trace DR1524 MSW inverter, Outback Flexmax 80 MPPT charge controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 30th year.

Comments

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    IMHO, it depends.

    In my experience, true deep cycle batteries do "okay" in starting applications for boats. I wouldn't count on them to start my car in the cold though.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    If I got 11 years the first time, I might do exactly the same thing the second time. The batteries must have stayed somewhat cool as a rule.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Question is, is the proposed use of deep cycle batteries to use them for loads other than starting? Doing so may reduce capacity when starting is required, otherwise there should be enough capacity to start since in parallel the plate count is double, in a pinch I've used a single 45Ah deep cycle to start my mini escavator with a 2.2 liter diesel. 
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • 706jim
    706jim Solar Expert Posts: 514 ✭✭✭✭
    I was just thinking that they might perform better when the boat is anchored and the electric fridge runs for a few days. I keep a Honda EU1000 as backup though.
    Island cottage solar system with 2500 watts of panels, 1kw facing southeast 1.3kw facing southwest 170watt ancient Arco's facing south. All panels in parallel for a 24 volt system. Trace DR1524 MSW inverter, Outback Flexmax 80 MPPT charge controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 30th year.
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    11 years is pretty good. Like softdown says, doing the same again may not be a bad idea unless the application has changed.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Did the refrigerator run on start batteries when anchored, previously ?
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    706jim said:
    I was just thinking that they might perform better when the boat is anchored and the electric fridge runs for a few days. I keep a Honda EU1000 as backup though.
    In that case, deep cycle would be a lot better for loads and still provide plenty of cranking power for a 350. They may run a really small fridge for quite some time.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    I see the OP lives in an island cottage? Been thinking about islands lately. Spent a lot of time evaluating Iceland and the islands around it. When one is really ready to say "F*** Off" to the world - there are islands off of Iceland.

    The Philippines have a few thousand islands and most are uninhabited. But I get weary of heat and humidity as my over sized head needs a lot of cooling it seems.

    There are a lot of islands off the west coast of Canada and in southern Alaska. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    A couple of interesting things about islands...

    They tend to be highly valued for privacy, yet are accessible and viewable from 360° around them (plus view from above). Almost voyeuristic.

    Once on one, one's mental "zone of exclusion" expands greatly. An apartment might have an exclusion zone of inches, like personal space on the elevator. On an island, it's miles.

    Just an observation.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter