Advice please...

alyazalyaz Solar Expert Posts: 114 ✭✭✭
Great forum. Have been looking for a post similar to my situation, but have not found anything, so all advice/suggestions are welcomed.

We just purchased a home that has:
-a 24 volt battery bank - 12 2 volt Davidson batteries;
-six 80 watt sharp solar modules;
-Xantrex c40 controller;
-Magnum inverter/charger;
-Magnum remote control;
-Xantrex battery monitor.

Recently we purchased four additional sharp 240 watt solar modules and an Apollo MPPT controller.

My understanding is that the operating voltages between the older 80 watt modules and new 240 watt modules would not be close enough to allow all the modules to be hooked to the Xantrex C40 controller or to a newer MPPT controller (although I have talked to two solar installers that said they are 'close enough.') I don't want to be 'close enough'...

So our thought was to hook the new 240 watt modules to the new Apollo MPPT controller and leave the older 80 watt modules hooked to the C40 controller.

My question(s) are being that the C40 uses older technology (pulse modulation) and the Apollo uses MPPT. How can two controllers using different charge methods be hooked to one inverter/charger and efficiently charge a 24 volt battery bank?

Is a person better off to replace the C40 with a MPPT controller too, maybe a Rogue?

Hope the questions make sense.

Regards,
3.3 kW solar.  3 Midnite Solar controllers; 5 lightening suppressors.  Magnum’s inverter; auto gen start, BMK.  Davidson 2 v FLA’s - 24v bank.  Perkins diesel gen.

Comments

  • petertearaipetertearai Solar Expert Posts: 464 ✭✭✭✭
    Re: Advice please...

    Use the new controller on your new panels.This will give you some redundancy should a controller fail.
    Buy a new controller should your old one fail.
    If you want a more detailed answer re combining the new and old panels you will need to post the full specs ie voc and so on.
    Regards peter
    2225 wattts pv . Outback 2kw  fxr pure sine inverter . fm80 charge controller . Mate 3. victron battery monitor . 24 volts  in 2 volt Shoto lead carbon extreme batterys. off grid  holiday home 
  • icarusicarus Solar Expert Posts: 5,433 ✭✭✭✭
    Re: Advice please...

    As fr as the two sets of panels,, what is the Vmp of each set? As for " close enough" it really depends on how close they are.


    And yes, you can certainly use two controllers on one battery bank. If you are going to upgrade the one controller, I reall y like the Rogue.


    Tony

    PS, welcome to the forum, good lock and keep in touch,

    T
  • alyazalyaz Solar Expert Posts: 114 ✭✭✭
    Re: Advice please...

    Thanks gang.

    Here are some specs. I wish the suppliers/manufacturers used the same terminology to make things easier for us noobs....

    Sharp 80 watt panels (six):
    Panel Specifications –
    Open Circuit Voltage (Voc): 21.6 V
    Maximum Power Voltage (Vpm): 17.3 V
    Short Circuit Current (Isc): 5.15 A
    Maximum Power Current (Ipm): 4.63 A
    Maximum System (DC) Voltage: 600 V
    Series Fuse Rating: 10 A


    Sharp 240 watt panels (four):
    Panel Specifications -
    Voltage Maximum Power 30.1
    Current Maximum Power 7.98
    Voltage Open Circuit 37.4
    Current Short Circuit 8.65

    Regards,
    3.3 kW solar.  3 Midnite Solar controllers; 5 lightening suppressors.  Magnum’s inverter; auto gen start, BMK.  Davidson 2 v FLA’s - 24v bank.  Perkins diesel gen.
  • petertearaipetertearai Solar Expert Posts: 464 ✭✭✭✭
    Re: Advice please...

    Looking at those specs I would go with 2 separate controlers.
    Regards Peter
    2225 wattts pv . Outback 2kw  fxr pure sine inverter . fm80 charge controller . Mate 3. victron battery monitor . 24 volts  in 2 volt Shoto lead carbon extreme batterys. off grid  holiday home 
  • alyazalyaz Solar Expert Posts: 114 ✭✭✭
    Re: Advice please...

    thanks for the feedback. i ended up ordering a Rogue MPPT controller to replace the Xantrex C40.

    Marc at Rogue was extremely helpful and it was so refreshing being able to speak to such a knowledgeable person, on numerous occasions.

    Regards,
    3.3 kW solar.  3 Midnite Solar controllers; 5 lightening suppressors.  Magnum’s inverter; auto gen start, BMK.  Davidson 2 v FLA’s - 24v bank.  Perkins diesel gen.
  • alyazalyaz Solar Expert Posts: 114 ✭✭✭
    The plan...

    Thanks for everyone's input. As this stuff is way over my head, I just want to ensure I've got it right... Here's the plan... any feedback on what I believe I have gathered from forum members, would be appreciated.

    Equipment in place:
    Magna Sine - Magnum Inverter/Charger; Model MS4024PAE.
    24 volt battery bank - 12-2 volt Davidson batteries.
    Magnum ME-RC Remote Control.
    Xantrex Battery Monitor.
    Xantrex C40 controller.
    Six Sharp 80 watt PV modules.

    First mod:
    Xantrex C40 - is being swapped out with a Rogue MPT-3024 controller:
    (30-amp output, 12-volt or 24-volt / 12-volt or 24-volt nominal PV arrays (60-volt Voc maximum)

    Sharp 80 watt panels (six):
    Panel Specifications –
    Open Circuit Voltage (Voc): 21.6 V
    Maximum Power Voltage (Vpm): 17.3 V
    Short Circuit Current (Isc): 5.15 A
    Maximum Power Current (Ipm): 4.63 A

    ???*These are best hooked up two in series and then parallel to the Rogue 3024 controller. fuse on each of the three strings...

    *****************************************************************
    Second Mod:
    Soon to be added:
    Apollo T80HV controller :
    (Maximum output current 80 Amps continuous at up to 45oC/113oF
    Battery voltages 12, 24, 36, or 48 VDC nominal
    Max PV input current 70 Amps
    Input voltage range 16 to 160 VDC operating 200VDC Maximum Open Circuit Voltage
    Charge 24v batteries from 34 to 160* volt PV arrays

    Sharp 240 watt panels (four):
    Voltage Open Circuit (Voc): 37.4 V
    Voltage Maximum Power (Vpm): 30.1 V
    Current Short Circuit (Isc): 8.65 A
    Current Maximum Power (Ipm): 7.98 A

    ???*These are best hooked up two in series and then parallel to the Apollo controller... fuse on each of the two strings...

    Regards, Al
    3.3 kW solar.  3 Midnite Solar controllers; 5 lightening suppressors.  Magnum’s inverter; auto gen start, BMK.  Davidson 2 v FLA’s - 24v bank.  Perkins diesel gen.
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