mppt charger options (nom. 60v, 35a)

al128

hi there,

the new house is being nearly finished, so I am now trying to get all the pieces of the puzzle together....

i have 30 units of siemens ps75 panels, which I plan to run in a 5x6 array for a nominal 60v, and roughly 30 or so amperes ...

inverter will be a victron 3000w (230v/50hz) ... fed from a 24v batt. bank


I will be off-grid ...

what are my option for mppt chargers?

- outback fm 60 / 80
- xantrex XW-mppt60
- WHAT OTHER MAKES/MODELS ?????


My priorities are
- reliability (i am in south america and any warranty-claim will likely take me off sun for 3-6 weeks)
- track record
- efficiency


what are my options and what are the good the bad and the ugly of the above (I seem to recall that outback has "issues" with their last line of chargers)?

thx for sharing your experiences
al

tallgirl

Re: mppt charger options (nom. 60v, 35a)

Al,

TIm (blackswan555) is another Outback board regular, and he should confirm what I have to say -- the firmware problems in FM60 and FM80 controllers have apparently been resolved in the newer (2.00 level) firmware.

The cost difference between FM60 and FM80 is smaller enough, and the tendency to add panels over time (because loads also increase) high enough that I'd recommend the FM80.

mike95490

Re: mppt charger options (nom. 60v, 35a)

Morningstar will soon (mid November '09) have a 60A MPPT controller

Midnight Solar also has a 60A class controller in the wings

blackswan555

Re: mppt charger options (nom. 60v, 35a)

I would recommend the Outback FM, I run 5 sites with them and have found them reliable and efficient , The only one I have had a problem with was not it`s fault and Outback had a replacement to me from USA to Ibiza, Spain in 6 days,(our postal system, you are usually lucky to get anything in a month) You can not beat their tech service & back-up,
I would also look at the VFX 3024E inverter,http://store.solar-electric.com/vfx3024e.html If you could build it all one manufacturer, It will talk to each other without the need for multiple temp sensors and other setup issues.

Have a good one
Tim

Edited to add, do you have any other means of charging ? A generator ?

Have a look at the Outback Forums http://www.outbackpower.com/forum/ for more info

crewzer

Re: mppt charger options (nom. 60v, 35a)

i have 30 units of siemens ps75 panels, which I plan to run in a 5x6 array for a nominal 60v, and roughly 30 or so amperes ... inverter will be a victron 3000w (230v/50hz) ... fed from a 24v batt. Bank… I will be off-grid ... what are my option for mppt chargers?

Al,

A PV array’s STC power limit for a system with a 24 V battery bank and using a 60 A charge controller is typically ~1,600 W STC or so.

Since you’re looking at a 2,250 W STC array, the "nominal 60 V and roughly 30 A" input from the array to the controller will be converted to "nominal 29 V and roughly 60 A" from the controller to the battery bank, not including periodic surges.

Accordingly, you’ll need to consider either single 80 A controller (i.e., an FM80), or a pair of smaller controllers (~40 A to 60 A each) and split the array.

HTH,
Jim / crewzer

al128

Re: mppt charger options (nom. 60v, 35a)

crewzer wrote: »

Al,

A PV array’s STC power limit for a system with a 24 V battery bank and using a 60 A charge controller is typically ~1,600 W STC or so.

Since you’re looking at a 2,250 W STC array, the "nominal 60 V and roughly 30 A" input from the array to the controller will be converted to "nominal 29 V and roughly 60 A" from the controller to the battery bank, not including periodic surges.

Accordingly, you’ll need to consider either single 80 A controller (i.e., an FM80), or a pair of smaller controllers (~40 A to 60 A each) and split the array.

HTH,
Jim / crewzer

thx for catching that one, Jim ....

I was unaware that I need to divide the watts of the array by the voltage of the battery bank (24v) ... I always devided by the voltage of the array (60v)

how would a 2 charger setup work ... how would they NOT step upon each other's feet? ... (given, the FM80 is still cheaper than 2 40A units)

again,thx ... you saved me a lot of hassles down the road

crewzer

Re: mppt charger options (nom. 60v, 35a)

Al,

Multiple controllers would need to be "normalized". You'd basically need to calibrate their voltmeters, and the absorb- and float parameters (target voltages and time) should be the same values for each controller.

FWIW, a pair of OutBack FM charge controllers can be networked via a Mate and Hub, and whichever controller reached float first would signal the other to follow suit.

If you go with two controllers, you'll also need two PV array combiner boxes, or one with two internal "halves":



Three circuit box: http://store.solar-electric.com/mnpv3.html
six circuit box: http://store.solar-electric.com/mnpv6.html
12 Circuit box (two sixes): http://store.solar-electric.com/pspv.html
Another 12 circuit (2 x 6): http://store.solar-electric.com/misomnsoarco2.html

HTH,
Jim / crewzer