New outback flexmax 60 charge controller

rake1

Just wondering if anyone has experience with one of these.I have a new FM60 I am trying to set up for my camp but am trying to set it up at home with just a Battery no array. I have read the manual a couple of times and set this up as best I can but have some questions I would like answered. First I have nothing connected to my AUX so am I right in saying I can just ignore it for now? I have the Absorb set for 1 hour 14.7 and float 13.6v, absorb end amps is at 0,Mppt mode auto track,Park MPP 78% Mpp range min 1/2 max 90%.Rebulk is 12.4V My question about rebulk is if I go to bed and my battery voltage is 12.3v but because of setting all night it is at 12.6 in the morning will FM60 wake up and go into a charge cycle or will it wait until the voltage drops to 12.4 during the daylight hours? This is a common occurrence for be to get up in the morning at my camp and the voltage has gone up to say 12.6 over night. I also can't find the low battery disconnect in the setting other than in the AUX settings, where can I find the low batt disconnect? One other question,if I charge my batteries with my battery charger and Generator do I have to do anything with the FM60?
Thanks for your help

mike95490

I understand Rebulk to cause a complete Bulk & Absorb cycle to begin, after the rebulk voltage setpoint is reached (for some amount of time, 30 seconds or so) once triggered, a slow recovery voltage should not inhibit rebulk when solar allows for it to begin

Raj174

@rake1
The FM60 will start charging every time it wakes up. The AUX function is the only battery disconnect method. Charging from other sources will not affect the FM60.

Rick

rake1

Rick I understand the FM60 will start charging every time it wakes up.I guess my question is when it is sleeping the voltage drops to 12.3v but by morning it is back up to 12.6v before daylight will it wake up at 12.6 if the rebulk is set at 12.4v I am thinking not but don't know

Raj174

@rake1
The charge cycle will reset when the sun goes down and rebulk will not run until after another full charge cycle has been  completed.

Estragon

Ignore aux settings for now. They generally have nothing to do with charging.

1 hour is likely a too short setting for absorb. I'd start with 3. With absorb end amps set to zero, the absorb to float transition will always be controlled by the timer. If setting end amps as an added control, 1-2% of battery amp-hour capacity is typical.

As a general proposition, rebulk happens when the controller is floating (sitting at 13.x volts, having completed a bulk/absorb cycle), a load comes on and pulls voltage down to Vrebulk for VrebulkTime. Say you get batteries full and a pump comes on. Battery voltage gets pulled down to Vrebulk for VrebulkTime, so the controller tries to do a new bulk/absorb cycle. This is a REbulk cycle, which is started from a float state. In the morning, the controller would be in a resting state, so should start a bulk/absorb cycle irrespective of REbulk voltage setting.

Low battery disconnect is typically a quite low voltage meant to protect equipment connected to the battery, not the battery itself. The default is likely ok, but if you want to change it the setting should be in a general menu. Settings for the aux terminals are meant for controlling a switch or load.

Settings for absorb and float voltage should initially be set to manufacturers recommendations and later adjusted as needed for your specific application. Your settings sound about right for a typical flooded lead acid 12v nominal bank.

It isn't really unusual to find voltage higher in the morning than it was at night. I pumped water when I got to the cabin a while ago, which pulled voltage low. It will recover overnight. It's now morning. Voltage on that bank recovered from 48.4 to 50.4 (48v nominal)

As far as doing anything with the FM if charging with AC, you don't really need to do anything. It's normal to charge from grid/generator with a charge controller attached. The controller itself is a small load though, so don't leave it on for weeks/months without charging to avoid running the battery down.

rake1

Great guys you answered just what I needed thanks.one question I have is with the wiring hook up. I noticed that in the manual it states that I can use one wire from my negative buss bar for the array negative and Battery negative back to the FM60 as they are bonded in the FM60. Are most doing that or still just using two wires?

Photowhit

I suspect most who use a bus bar and have their negative from the array coming to the bus bar, usually at a breaker box. It saves extra wiring. Here is my setup with Midnite classics, they like most charge controllers have a common negative terminal for array and battery.

The 2 soon to be 3 charge controllers would be over the max for 1" conduit if there were 6 sets of wires instead of 3 along with the other wiring.


Here is a close up of the negative bus bar on one side of the shunt. The 2 connections on the lower half of the bus bar are the charge controllers.  The upper half are the 2 array's negatives.

Photowhit

LOL, I didn't look at the pics before I posted, I must have used larger conduit any way...

rake1

Thanks for the pic