Adding second charge controller

BenA
BenA Registered Users Posts: 15 ✭✭
Got a few thousand watts feeding a Classic 150 charge controller.  I need to add another 1kw of PV and another Classic 150.  Both of these controllers will charge a single battery pack.  I found one schematic doing this ..... and it just showed the outputs of the charge controllers tied together.

Do I need diodes to isolate the outputs of the two charge controllers? 

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,422 admin
    No diodes needed.

    Just make sure each 1/2 of the solar array goes to its own controller.

    I believe that midnite has a follow me function. You just need to connect the two controllers with a communications cable.

    You do not need to synchronize the two controllers. Without follow me function, the controllers will decide when the battery back is full at different times. May drive you nuts, but does not hurt anything.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    BB. said:
    I believe that midnite has a follow me function. You just need to connect the two controllers with a communications cable.
    And you may need to update the firmware on your older Classic. 

    As Bill said, you don't need to synchronize them, but if you don't, then make sure each of them has its own battery temp sensor.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • Vic
    Vic Solar Expert Posts: 3,207 ✭✭✭✭
    edited September 2016 #4

    YES,   it is recommended that all Classics that are using FollowMe on a single battery,  have identical versions of Firmware.

    Now,  a single Battery Temperature Sensor(BTS),   is all that is required,  EDIT on any of the Classics <.  Classics still include a  BTS.

    FollowMe does work very well.

    One may still want to massage the Absorb,  and perhaps EQ voltages (for Flooded batteries),  to help keep them a bit better balanced,  in Absorb, (and perhaps EQ) ...

    FWIW,     Vic

    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.