Verify midnite 150 connection

Started by merelda, August 22, 2012, 11:05:09 AM

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merelda

Hi,

I have a 2 x 24 OPzS (2V 3100Ah) batteries for 48V, 6200Ah battery bank connected to 30kW solar array.

Is it technically feasible to use seven of the Midnite Classic 150 as charger controller?
If not, what other options do I have?

Thanks!

Merelda

Halfcrazy

Yes it is feasible to use 7 of them if needed. I would recommend using some best practice for that large a system and have the charge controllers wired through to the batteries not to the inverter box. We can do a wiring diagram for large systems if needed we should have one anyhow.

Ryan
Changing the way wind turbines operate one smoke filled box at a time

niel

wow, what are you powering with all of that? :o

merelda

Quote from: Halfcrazy on August 22, 2012, 02:50:04 PM
Yes it is feasible to use 7 of them if needed. I would recommend using some best practice for that large a system and have the charge controllers wired through to the batteries not to the inverter box. We can do a wiring diagram for large systems if needed we should have one anyhow.

Ryan

Hi Ryan,

Thanks for the advice, it would be great to have a look of the wiring diagram.
Thanks!

Quote from: niel on August 22, 2012, 05:04:52 PM
wow, what are you powering with all of that? :o

Hi Niel,

My load is 150kWh/day..  and I designed for 50% discharge and 1 day autonomy :-\

niel

you may need to watch as there will be times you won't get full sun for 5hrs. what's worse is the power rating on pvs is stc and most often what is really gained is far lower. about 77% gt and about 52% og.

Robin

150Kwh per day is a lot. I have talked to people that wanted to heat their hot tub with solar. Once they got the price tag, they decided to use other methods. Solar can certainly power your loads, but does your design actually make sense? We would all love to hear more about your system.
Robin Gudgel

nigel

#6
Consider daily discharge to 50% slams the life of a battery Quoting Rolls series 5000 series with a average 15 year life expectancy

20% DOD Life Cycles = 5000 (approximate 13.6 yrs) 50% DOD Life Cycles = 3200 (8.7 years)

Plus I don't think you have calculated system looses. Based on your original calculation that you had a 6200 ah 48v bank
150 kw hours is indeed 3125 amp hours at 48 volt so around 50% of your  6200 ah bank. But that's assuming everything
is 100% efficient, which its not. Factor in on a new system 60% efficency and your even deeper in the discharge zone !

Also if your battery capacity quoted  is at the C100 or C120 rating which battery manufacturers seem to  like . It will be more like a  5000 ah @ C20 which is the more appropriate guide for daily discharging

Amended after Dustins correct comment below.


dbcollen

Nigel,

I think you misread her specs "I have a 2 x 24 OPzS (2V 3100Ah) batteries for 48V" I read that as (2) parallel arrays of 24 2v 3100ah cells for 6200ah

Dustin

nigel

Dustin thanks Ive amended above accordingly !

merelda

Hi everyone,

Thanks for the reply.

Nigel you're right, my initial battery capacity is designed to be 15000Ah, but then I realised that makes my system entirely unfeasible.
Since my peak load coincides with the radiation so I cut down on the battery and used diesel generator as back-up, saved about 6 years in my payback time.