Mixing/matching Midnite and Outback Charge Controllers

[slferris]

I presently have 24 75-watt solar panels running a 48 volt system connected to an older Outback charge controller.  I want to add to my system with 12 180-watt panels using a Midnite controller. The existing arrays are mounted on two masts outside my house.  The new one would be mounted on a third mast.  Could you advise me on the following:

1. Would it be possible to run all my panels, the 24 old ones and the 12 new ones, on a single Midnite controller using the existing wire between my arrays and house and not using the Outback controller at all?  If so, which Midnite controller would be appropriate and what other equipment might have to be upgraded, e.g., breakers, etc.?

2. If number 1 above is not practical and I use both an Outback controller along with a Midnite controller and a second line between my solar panels and my house, is it important to synchronize the two controllers?  lf so, how do you do that?

3. Assuming either of these alternatives is viable, which would be the more desirable from the standpoint of both cost and efficiency?

[Westbranch]

you will need to post the specs of those different panels for a good response to point number one.

# 2 : the 2 controllers should manage their own loads and monitor battery SoC independently.

#3 depends on the answer to #1  but probably #2 is most effective.still need more data on panels.

[tallgirl]

# 2 : the 2 controllers should manage their own loads and monitor battery SoC independently.

Although the Classic includes something that looks like a battery monitor, neither OutBack nor MidNite have true state of charge monitors in their charge controllers.  What both do is look at battery voltage to decide what's up.  This is why it is SO important to use a high-quality volt meter to make sure the two charge controllers agree with each other, as well as reality.

And for a SoC meter, the FLEXnet DC is a nice little gadget.  I even have a paper that explains the finer points of making sure it works correctly ...