105ah on 90w pannels

henna
henna Registered Users Posts: 3
hi guys im new to the forum. im from south afica looking for some basic advice.

story goes as such, i love going camping and always been a minimalist, never needed much, but now i have problems, #1 the missus, i need some sort of lighting and #2 i run a small bass boat on a 30lb trolling motor. so my two 105ah batts are taking a beating.

so what i want to find out, will i be able to recharge 80% of a 105ah with 7-8 hours of good sun (rotating the angle) with a 90w pannel. rotating the batts with weaker one running two 5w leds at night for 4 hours max.
 Please forgive my ignorance if im way of :D

hope to hear from someone more experienced.

Comments

  • South Africa
    South Africa Solar Expert Posts: 295 ✭✭✭
    Welkom Henna, jy is by die regte plek. Die forum mense hier verstaan solar sisteme. 
    Translated: Welcome Henna, you have come to the right place. These forum users really understand solar. 
    5kVA Victron Multiplus II, 5.2kW array, 14kWh DIYLifepo4 bank, all grid-tied.


  • South Africa
    South Africa Solar Expert Posts: 295 ✭✭✭
    edited May 2016 #3
    To charge 1 x 105ah battery, you need at least 5% - 13% of the AH to charge it properly.
    So min +-5.25amps to max 13.65amps. 

    You have 2 batteries, assuming 12v, so it is 210ah, so is 10.5amps, max 27.3amps.

    You are using it during the day, want lights at night, so you have to go for max charging of 27.3amps

    A 90w panel is completely insufficient. Sorry.
    5kVA Victron Multiplus II, 5.2kW array, 14kWh DIYLifepo4 bank, all grid-tied.


  • henna
    henna Registered Users Posts: 3
    south africa thanx for the reply, im only looking at charging the one battery for use on the boat. the secondary one wil only be used for minimal lighting
  • South Africa
    South Africa Solar Expert Posts: 295 ✭✭✭
    The Stecca, for one battery only, will work, at max capability. If I was you, I would go for a Victron 75/15 or 75/30 charge controller, because once this gogga bites, you are going to want to do more i.e. why only use it for camping? At home, run your alarm system from the system 24/7, use it as a backup for lights with power failures. Just get a 350va small 12v inverter for powering your TV?

    For IF I understood BB's teachings right, You will need:
    +-96watt array, to charge at 5%, which is good for weekend use.
    192watt array to charge at a 10% rate - good for daily charges.
    250watt array to charge at 13%, - which, if it was me, I would have gone for, mounting on the bass boat for shade, and a portable frame for at the camp site.  :D

    The above takes into account 1 day spare, 50% DOD, 77% system efficiency, so you will have ample power.
    5kVA Victron Multiplus II, 5.2kW array, 14kWh DIYLifepo4 bank, all grid-tied.


  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    edited May 2016 #7
    you could also directly  hook up a smaller (90W) panel on the boat without a controller to boost the power used when using the trolling motor, ie supplement the battery and recharge it a bit while casting.. it can add a few hours a day of electrifying trolling before the gas is used... I frequently re-aimed the panel towards the sun for max output in my cartopper 12 footer
    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,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • oil pan 4
    oil pan 4 Solar Expert Posts: 767 ✭✭✭✭
    If you are trying to squeeze the most of a few panels you have to get a real MPPT charge controller.

    Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.

    Solar roof top GMC suburban, a normal 3/4 ton suburban with 180 watts of panels on the roof and 10 amp genasun MPPT, 2000w samlex pure sine wave inverter, 12v gast and ARB air compressors.

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Even rotating a panel to get 7-8 hours of sun, will require 2 days to harvest that much,  Only about 5-6 hours of good sun in the very best locations, Morning and afternoon sun has less power because of all the atmosphere it has to pass through,
    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
    gen: http://tinyurl.com/LMR-Lister ,