Author Topic: equalizing batteries with 2 different controllers  (Read 1139 times)

Nick

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equalizing batteries with 2 different controllers
« on: April 27, 2019, 05:25:34 PM »
I just added a Classic 150 to my system . Using 2 controllers ones an outback and the other is a classic. When equalizing the batteries do you set both chargers to equalizing the batteries or just use the 1 controller ?
9 x 250w panels 3 strings on each controller. 900Ah 24v

Vic

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Re: equalizing batteries with 2 different controllers
« Reply #1 on: April 27, 2019, 06:42:33 PM »
Hi Nick,   Welcome to the Forum.

You will want to use both Charge Controllers,  to maximize available power.  This will shorten the time it takes to reach the set EQ voltage.

When the set EQ voltage is reached,  one controller will probably supply more current than the other (similar to what happens in Absorb).

I assume that you have Flooded Lead Acid (FLA) batteries.

Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

Nick

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Re: equalizing batteries with 2 different controllers
« Reply #2 on: April 27, 2019, 09:42:52 PM »
Hi Vic and thank you for reply. Yes they are flooded lead acid batteries. I'm also not sure about the temp limits ( min and max voltage ) max charge rate is absorb 29.4v, float 27.9v and eq 31.2v.
I was going to set min at 27.9v and max at 31.2v . I can't get any other spec for these batteries .

Vic

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Re: equalizing batteries with 2 different controllers
« Reply #3 on: April 28, 2019, 06:50:24 PM »
Hi Nick,   Thanks for the added info.

What brand and model number,   are those batteries.

Some of us,  Temperature Compensate the EQ voltage.   If you will compensate the EQ,  then you will probably need to raise the Max voltage Limit.   The manufacturer of your batteries may have guidance on this.   The  compensation value would depend upon the coldest temperature you would expect for the batteries,   and  the value of the compensation (the number of mV/cell/degree C)

If your batteries got very cold,   the Absorb compensation could possibly get Limited by the Max Limit value.   This is probably not a factor for most locations in Australia.

The Min Limit value probably should be set to a lower value,   again depending on how warm you would  expect for the batteries when the Classic is in Float.

FWIW,  Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

Nick

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Re: equalizing batteries with 2 different controllers
« Reply #4 on: April 28, 2019, 11:28:32 PM »
Hi Vic , the batteries are a Raylite  MIL25S 900Ah .
Temperature compensation 2mV per cell per degree .
I've attached a copy of the specs. Everything else is just on specific gravity . It doesn't get that cold but it does get very hot, up in to the 40's  . I'm located up in the Northern River of NSW . ,I've attached a copy of specs