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Expandable Magnum 4448 PAE

Dgrblu

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Apr 14, 2022
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Orygun
Off grid system, 48 vdc (8 crown 6v cr430), 6s3p panels (265 w), Midnight Classic 150 CC, ms4448 pae inverter wired into a Magnum panel. This panel is setup to add another inverter and can be configured into a master/slave inverters running in parallel output.

I am wanting to add 5s3p (320w) array plus another string of batteries also wired series/parallel.

Do I need another Classic 150 to service the added set of batteries? Could the existing Classic charge both sets of batteries. Can both arrays land on the same buss as the Classic?

TIA
 
I run 3 x Midnite Classics 150. They have a limit - https://www.midnitesolar.com/sizingTool/ I have mine overpaneled a little bit - 3s6p of 285w = 5,130w - because at 80% (typical power) it's effectively less than Midnite Classic max 98% of the year and I have output amps throttled at 80a (of 86a possible).
1664145035982.png
However, adding 5s3p to an existing 6s3p PV input is way to much (see the sizing tool above) and at best you'll waste most of the power in spring/summer. I'd go with a 2nd charge controller.

If you're saying you have 2 separate batteries - then trying to hook 1 Midnite to both will in effect cause them to be hooked in parallel. If the additional batteries are parallel'ed in to 1 'battery bank' with 1 big plus and minus - then sure. I have 8 x 48v batteries paralleled to 1 plus and minus bus and 3 x Midnites connected to the bus - e.g. 3 Midnites all charging the same battery bank.
 
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Thanks.
So, you are using the " follow me " function of the classic. Master classic set to the parameters of the batteries ie absorb, float and equalize voltages/duration settings and the others follows the master.
 
Thanks.
So, you are using the " follow me " function of the classic. Master classic set to the parameters of the batteries ie absorb, float and equalize voltages/duration settings and the others follows the master.
Although "follow me" is an interesting feature, I don't bother with it and set each Midnite separately to the same numbers. Since it has internet and remote software, it's pretty easy. The overview app looks like this - you just select each one and change settings.
1664156060479.png

Each Midnite can read the battery voltage a little bit differently - such as 51.2v on one and 51.3v on another, but you can adjust this via the 'voltage calibration offset' option if it's a concern. In my case it's not a problem.
 
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Okay battery question, you have 8 single batteries that are 48 volts each where as mine are 8 six volt batteries wired in series for 48v. Are your batteries flood lead acid?
 
Okay battery question, you have 8 single batteries that are 48 volts each where as mine are 8 six volt batteries wired in series for 48v. Are your batteries flood lead acid?
Each one of my 8 batteries is made up of 14 'cells' in series. They are each 14s100p lithium-ion 18650 cells. I have 8 of them with the same capacity in parallel for 1 larger battery - e.g. I use the term 'battery bank' when there are multiple individual batteries in parallel.

You're single battery is 8s1p of lead acid. You could do a 2nd 8s1p of lead acid with similar capacity or a 4s1p of 12v lead-acids with similar capacity and hook both in parallel. But it's not clear to me what you're thinking/planning. For example, to expand, you should stick with lead-acid so both batteries are the 'same chemistry' which means they'll have compatible voltage ranges and you operate them similarly with respect to depth of discharge.

Could you explain what you're planning?
 
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Adding another Magnum ms448pae, if they ever begin to ship, and running both inverters outputs in parallel then splitting that to two places, cabin and barn. Will also be acquiring 16 6v lead acid and wiring them in a series/parallel 48v configuration. Thought I could use one classic but the sizing tool explains why not.
 
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