Adding solar panels

Discussion about the MX60 Charge Controller

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gsubbu
Forum Member
Posts: 18
Joined: Sun Jun 25, 2017 8:57 pm
My RE system: 3KW VFXR3048E INVERTER- Firmware Version 1.6.15
FLEX MAX 80 CHARGE CONTROLLER- Firmware 3.3.0

MATE 3 system . Firmware version 3.19.1

48 V BATTERY SYSTEM

12V, 200AH@C10 RATE - 4 IN NO RIGGED IN SERIES.Lead Acid Batteries

TRINA SOLAR 325 W- 12 IN NO

3 PANELS IN SERIES.

3 STRINGS , ONE STRING CONTAINS 6 PANELS IN SERIES PARALLEL COMBINATION

Adding solar panels

Post by gsubbu »

Hello all , I have joined newly to this forum. I have installed a new system in Bengaluru, India.( Max temperature 39.8 and min 7.8 degree Centigrade in the past 100 years).

Usually temperature is between 25 to 30 Degree Centrigrade.


System details are as follows :-

3 kW Inverter VFXR3048E.

Charge controller MX 60.

48v system consisting of 4 lead acid batteries of 200 AH @C10 rate.

9 trina solar panels of 325 W. rigged 3 series , 3 strings.( 2925 W) MAXIMUM VOC 131V.


I have been reading up on the queries on the forum . I have been using the system for past one month.


I have space for adding three more solar panels ( 975 W).


Total watts would be 3900.


I was deliberating on two options:-


1. Swap my charge controller to MX 80 and add three panels.

or


2. Add an additional battery and go to 60 V , and add three panels.



Either way dont intend to change my inverter as i would like to oversize the panels and extract maximum output.



I would lean to the second option . Any thoughts or inputs ?
blackswan555
Forum Emperor
Posts: 2637
Joined: Sat Aug 30, 2008 5:50 am
My RE system: Other peoples, VFX "E" versions, FLA`s, Generators.
Location: Ibiza Spain,

Re: Adding solar panels

Post by blackswan555 »

Both "would work" But you already have too much panel / too little battery in the system now ? recommended is 5 to 15% of 20hr rate, You have more than double already ?
More batteries I think may be a better option ?

Tim

ps, what have you changed defaults to in settings ? absorb voltage and time ?
My comments are based on my experience and research, They are not endorsed or checked by Outback.I am an independent British electrician living in Spain, So please take this into account when reading /acting on my post`s.
gsubbu
Forum Member
Posts: 18
Joined: Sun Jun 25, 2017 8:57 pm
My RE system: 3KW VFXR3048E INVERTER- Firmware Version 1.6.15
FLEX MAX 80 CHARGE CONTROLLER- Firmware 3.3.0

MATE 3 system . Firmware version 3.19.1

48 V BATTERY SYSTEM

12V, 200AH@C10 RATE - 4 IN NO RIGGED IN SERIES.Lead Acid Batteries

TRINA SOLAR 325 W- 12 IN NO

3 PANELS IN SERIES.

3 STRINGS , ONE STRING CONTAINS 6 PANELS IN SERIES PARALLEL COMBINATION

Re: Adding solar panels

Post by gsubbu »

Thanks for your input. I have not changed any of the default parameters.


My system is grid tied and am exporting excess power. Hence the query to maximize the output power to the grid. Hope that explains.
blackswan555
Forum Emperor
Posts: 2637
Joined: Sat Aug 30, 2008 5:50 am
My RE system: Other peoples, VFX "E" versions, FLA`s, Generators.
Location: Ibiza Spain,

Re: Adding solar panels

Post by blackswan555 »

Sorry was assuming off grid, I do not do grid so can not help, But default settings are not good, One of the GT guys step in ?

Tim
My comments are based on my experience and research, They are not endorsed or checked by Outback.I am an independent British electrician living in Spain, So please take this into account when reading /acting on my post`s.
gsubbu
Forum Member
Posts: 18
Joined: Sun Jun 25, 2017 8:57 pm
My RE system: 3KW VFXR3048E INVERTER- Firmware Version 1.6.15
FLEX MAX 80 CHARGE CONTROLLER- Firmware 3.3.0

MATE 3 system . Firmware version 3.19.1

48 V BATTERY SYSTEM

12V, 200AH@C10 RATE - 4 IN NO RIGGED IN SERIES.Lead Acid Batteries

TRINA SOLAR 325 W- 12 IN NO

3 PANELS IN SERIES.

3 STRINGS , ONE STRING CONTAINS 6 PANELS IN SERIES PARALLEL COMBINATION

Re: Adding solar panels

Post by gsubbu »

Well going through the books and learnt that i cannot add a extra battery and move to 60V system as my inverter is rated only for 48 V system.


That leaves me with no option but change the charge controller and upgrade to mx 80 .


Am i correct ?
Mike Curran
Forum Emperor
Posts: 2271
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Adding solar panels

Post by Mike Curran »

Your MX60 is maxed out now (2925W ├À 48volt system = 60amps) so changing to an FM80 is the route I would take if I were you.
https://smart.tigoenergy.com/p/pZXn7SZQyO45?date=2021-04-19
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
gsubbu
Forum Member
Posts: 18
Joined: Sun Jun 25, 2017 8:57 pm
My RE system: 3KW VFXR3048E INVERTER- Firmware Version 1.6.15
FLEX MAX 80 CHARGE CONTROLLER- Firmware 3.3.0

MATE 3 system . Firmware version 3.19.1

48 V BATTERY SYSTEM

12V, 200AH@C10 RATE - 4 IN NO RIGGED IN SERIES.Lead Acid Batteries

TRINA SOLAR 325 W- 12 IN NO

3 PANELS IN SERIES.

3 STRINGS , ONE STRING CONTAINS 6 PANELS IN SERIES PARALLEL COMBINATION

Re: Adding solar panels

Post by gsubbu »

Have changed over to FM 80 . i also added three panels of trina 325W capacity.

So i have three strings.

String 1 - 6 panels, remaining two strings are with 3 panels each.


Also upgraded the fuse panels on the dc side where i increased to 25A for the doubled string.


My question is as follows;-


With maximum of 4 kw panels on top , the inverter is nicely chugging at 2.8 k for most part of the day, however what goes to the grid varies from 2.3 to 2.5. Minimal load

of 0.1 kw.

Shouldnt the inverter be putting out 3kw and also output to grid be 2.9 +? Am i missing something?


I have made no changes in mppt settings.

The sell voltage is set at 50 V ( reduced from default 52V). Also the absorb and float charges time have been set to 0 ( deliberately).
Mike Curran
Forum Emperor
Posts: 2271
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Adding solar panels

Post by Mike Curran »

gsubbu wrote: With maximum of 4 kw panels on top , the inverter is nicely chugging at 2.8 k for most part of the day, however what goes to the grid varies from 2.3 to 2.5. Minimal load of 0.1 kw.

Shouldnt the inverter be putting out 3kw and also output to grid be 2.9 +? Am i missing something?
In a perfect world, yes. But batteries, charge controllers and inverters are never 100% efficient. Take a look at what my 3.2kw system is doing right now:
Screenshot_20180126-111421.jpg
Despite 870 watts from my charge controllers, there's only 390 watts total going to my loads plus the grid. My battery is using some of this to hold a charge at 26.5 volts or so, and my inverter is using some in the process of inverting. If I had a newer battery I believe I'd be selling more, but that's just how it is with a 10 year old battery. You're doing good by comparison. - Mike
https://smart.tigoenergy.com/p/pZXn7SZQyO45?date=2021-04-19
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
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