Parallel or Series PV: Midnite Kid to charge Boathouse Battery Bank

AnawaAnawa Solar Expert Posts: 211 ✭✭✭
Here’s what I’m considering.

Installing 200 +/- Ah battery bank with 500 watt (2 panels) PV array at a covered boat dock. Pretty much settled on the Midnite Kid charger and will decide on panels and batteries according to best price. The Kid can handle either configuration (parallel or series) for standard panels, but I’m not sure which way to go. The cost of the equipment to configure either configuration seems to a wash, I’ll use an inexpensive MC4 Y connector to make the parallel so that I still deal with single positive/negative wiring into the PV disconnect/ground fault panel. I know this ain’t rocket science, but anybody there who would like to chime in? I’m thinking, is it better for this application to have 16-17 amps (with some 30 volts) going to the Kid rather than 8-9 amps and 50-60 volts. I have plenty of heavy wire left over from other projects, so wire gauge is not an issue. The PV runs are short, about 10 feet from array to PV panel and 18-20 feet to the Kid charger. The whip to the batteries would be about 10 feet directly out of the Kid (with inline fuse and disconnect) and the load panel (3 circuits max) will be mounted right next to the Kid charger. 

The final objective is to mount the 200 +/- Ah battery bank on a pontoon boat to run an electric trolling motor and to operate “house” lighting at night. The Kid will recharge batteries during daylight hours and provide some pre-set dusk time lighting at night. Any thoughts on configuring such an set-up appreciated. 

Thanks. 
Paul 
in Georgia

System 1: PV- 410w Evergreen, Mppt- Blue Sky Solar Boost, Batt - 225ah Deka AGM, 12v led house lighting,
System 2: PV- 215w Kyocera, PWM - Morningstar PS30, Batt- 225ah Deka GC's, 12v led house lighting, Dankoff 12v water pump,
System 3: PV- 1.5kw Kyocera, Grundfos 11 SQF well pump, 3000 gal above ground water storage, dom water & irrigation,
System 4: PV- 6.1kw Kyocera, Mppt- Outback FM80-2ea, Inverter- Outback FX3648-2ea, Batt- 804ah GB traction, Grundfos BMQE booster pump 240v, Mitsibushi mini-splits 240v, 18k and 15k

Comments

  • littleharbor2littleharbor2 Solar Expert Posts: 1,824 ✭✭✭✭✭
    If there's no shading issues then series wiring would work well. If there's any chance one, or both panels will be seeing shade then parallel wiring would be preferred.  This is going to be a 12 volt battery bank, correct?

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • AnawaAnawa Solar Expert Posts: 211 ✭✭✭
    I will have some shading issues during winter, so looks like parallel is the preferred set-up. And, yes, it’s a 12 volt system. 

    Thanks lil’ for the quick response!
    Paul 
    in Georgia

    System 1: PV- 410w Evergreen, Mppt- Blue Sky Solar Boost, Batt - 225ah Deka AGM, 12v led house lighting,
    System 2: PV- 215w Kyocera, PWM - Morningstar PS30, Batt- 225ah Deka GC's, 12v led house lighting, Dankoff 12v water pump,
    System 3: PV- 1.5kw Kyocera, Grundfos 11 SQF well pump, 3000 gal above ground water storage, dom water & irrigation,
    System 4: PV- 6.1kw Kyocera, Mppt- Outback FM80-2ea, Inverter- Outback FX3648-2ea, Batt- 804ah GB traction, Grundfos BMQE booster pump 240v, Mitsibushi mini-splits 240v, 18k and 15k
  • EstragonEstragon Registered Users Posts: 4,496 ✭✭✭✭✭
    The controller may also run a bit more efficiently bucking from a lower voltage in parallel. 

    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
Sign In or Register to comment.