I am getting ready to go with my system...

Dr. Dickie

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Sep 23, 2020
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162
I, of course, have a few questions. In looking at videos it seems that most folks use 4.1 V for their 100% SOC setting on the Batrium. I assume they probably use 3 V for the low voltage. Is that pretty much the accepted voltages that most folks use?
The 4.1 V seems a bit high for me, I was thinking more along the lines of 3.9V high and 3.1 V low--at least to start, to see what capacity I get from that.
These voltages would also dictate my solar charge controller setting (Midnite Solar)--which I am just now digging into.
Thanks
 

Wolf

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Sep 25, 2018
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4.05v to 4.08v on the high side and 3.4 to 3.5 on the low side is what I run. After 3.5v the 18650 discharge curve drops off pretty rapidly so no sense in stressing the cells beyond that.

Wolf
 

Dr. Dickie

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4.05v to 4.08v on the high side and 3.4 to 3.5 on the low side is what I run. After 3.5v the 18650 discharge curve drops off pretty rapidly so no sense in stressing the cells beyond that.

Wolf
Wow, thanks. That is what I needed to know.
 

daromer

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I have 3.5 resting and 3.2v in low on high current. In resting there aint much left below 3.4v.
 

Dr. Dickie

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Why I never thought to look into discharge curves to get my voltages,.... I astound myself at my incompetence. Thank god for this site.
I did find this now that I am looking.
1620922273184.png


Which looks like 3.5 might be good.
 
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OffGridInTheCity

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Dec 15, 2018
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Yes sir. I run within 3.5v low and 4.0v hi as the operating range for (what I hope will be) a very long life. The discharge curve is your friend in terms of understanding battery operations.

The ratios for me are 13kw PV array, 81kwh battery, and average of 58kwh/day consumption in spring. As soon as AC is required, this will jump to 65khw/day consumption in June, 81khw/day in Jul and top out at 103kwh/day consumption in Aug! Spring/fall is high PV but low heat or AC - so I have excess. BUT.... by restricting my operating range my yearly DOD average is 40% which I hope results in several 1000(s) of cycles. 6,205 more cycles and I'll actually break even!

I whish I could build a 6000kwh battery... and take things to a next level to smooth out some of these seasonal issues. That would be on the order of 700,000 cells - more than even @daromer has on hand! But can you imagine - it would get me on some kind of govt battery watch list!

As you operate for a while and collect basic stats you'll find your groove and then you can tailor your system to meet your goals :)
 
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Dr. Dickie

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Joined
Sep 23, 2020
Messages
162
Yes sir. I run within 3.5v low and 4.0v hi as the operating range for (what I hope will be) a very long life. The discharge curve is your friend in terms of understanding battery operations.

The ratios for me are 13kw PV array, 81kwh battery, and average of 58kwh/day consumption in spring. As soon as AC is required, this will jump to 65khw/day consumption in June, 81khw/day in Jul and top out at 103kwh/day consumption in Aug! Spring/fall is high PV but low heat or AC - so I have excess. BUT.... by restricting my operating range my yearly DOD average is 40% which I hope results in several 1000(s) of cycles. 6,205 more cycles and I'll actually break even!

I whish I could build a 6000kwh battery... and take things to a next level to smooth out some of these seasonal issues. That would be on the order of 700,000 cells - more than even @daromer has on hand! But can you imagine - it would get me on some kind of govt battery watch list!

As you operate for a while and collect basic stats you'll find your groove and then you can tailor your system to meet your goals :)
Thanks. I am setting up my Midnite Solar (trying to follow their directions). Should I use the "float" at 4.08 x 14 = 57.2V
 

OffGridInTheCity

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Dec 15, 2018
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Here's a quicky... if you have any question - please feel free.


Here are my "Basic" settings....
1) All the "Battery Voltage [ 48V ]v dropdown does is set values 'roughly' in range - then you can go in and customize them.

2) Disable Equalize by setting hi/un-attainable voltage + time of 00:00 + 0 Interval + 0 Retry . This doesn't apply to Lithium and you don't want it to run.

3) Absorb/Float are 'the same thing' - e.g. the max charge voltage. Float cannot be any higher than Absorb - 0.1v. So I just set Absorb to the voltage + 0.1v that I want and Float the voltage I want. In my case Absorb = 56.6v and Float = 56.5v. This translates to a max charge of 56v as reported by Batrium.

There's a bit of a difference between Absorb/Float settings and *actual* max charge as reported by Batrium. You can make adjustments in the "Tech" menu (below) but I just would up experimenting a bit made it match what I wanted as reported by Batrium. Easy to change/tweak and you'll find something that works for you.
1621020928240.png




Here are my "Advanced" settings...
1) Aux 1: is used to turn the AIMS inverter on/off. Right now its on at 51.5v and off at 48v. Typically I run at 49.5v off. The idea is to let the battery charge up a littler higher than low-cut-off so when it turns on it won't immediately hit low/cutt-off.

2) Output Amps are explicitly set to 80a because that's the breaker size I have on the wiring going to the battery. I had a case where my panels actually produced 85a and tripped the breaker and I was running around trying to figure out what happened!!

3) The "Capacity aH" (in the Battery Status section) you set to overall battery bank capacity. Mine is 1560.

1621021457278.png



On the "Tech Menu"....
1) Ending Amps, Rebulk... I just ignore these. The Ending Amps can be used (somehow) with Wizbang Jr (The shunt) to reset aH(s) for SoC stuff. See the reset at Net Ah at 100% SoC setting below.

2) Offsets - you an adjust this to bring the Midnite in alignment with Batrium is you want. I fooled with it - e.g. the "-0.5" voltage setting but just moved on to the comment up above.

3) I REALLY LIKE the Arc Fault feature and enabled it. This will detect 'bad connections' in your solar panel hookup if they are arcing due to intermittent connections. I had to decrease sensitivity by 1 number as it went off a couple of times

1621021824887.png




**Don't know how you feel about ModBus code but I have full working PHP code to read all these settings in batch for my internal DB and tracking. I didn't bother to do the 'writes' because its easy to set thru the interface. Happy to share the PHP if you want it.

This is how I get this 'low-tech' web page that refreshes every 5 secs... so I monitor the Midnites. I also parse the Batrium log every 5 mins and combine the 2 sets of data to produce this dashboard:
1621022479218.png
 
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Dr. Dickie

Active member
Joined
Sep 23, 2020
Messages
162
Here's a quicky... if you have any question - please feel free.


Here are my "Basic" settings....
1) Disable Equalize by setting hi/un-attainable voltage + time of 00:00 + 0 Interval + 0 Retry . This doesn't apply to Lithium and you don't want it to run.

2) Absorb/Float are 'the same thing' - e.g. the max charge voltage. Float cannot be any higher than Absorb - 0.1v. So I just set Absorb to the voltage + 0.1v that I want and Float the voltage I want. In my case Absorb = 56.6v and Float = 56.5v. This translates to a max charge of 56v as reported by Batrium.

There's a bit of a difference between Absorb/Float settings and *actual* max charge as reported by Batrium. You can make adjustments in the "Tech" menu (below) but I just would up experimenting a bit made it match what I wanted as reported by Batrium. Easy to change/tweak and you'll find something that works for you.
View attachment 25008



Here are my "Advanced" settings...
1) Aux 1: is used to turn the AIMS inverter on/off. Right now its on at 51.5v and off at 48v. Typically I run at 49.5v off. The idea is to let the battery charge up a littler higher than low-cut-off so when it turns on it won't immediately hit low/cutt-off.

2) Output Amps are explicitly set to 80a because that's the breaker size I have on the wiring going to the battery. I had a case where my panels actually produced 85a and tripped the breaker and I was running around trying to figure out what happened!!


View attachment 25009


On the "Tech Menu"....
1) Ending Amps, Rebulk... I just ignore these. The Ending Amps can be used (somehow) with Wizbang Jr (The shunt) to reset aH(s) for SoC stuff. See the reset at Net Ah at 100% SoC setting below.

2) Offsets - you an adjust this to bring the Midnite in alignment with Batrium is you want. I fooled with it - e.g. the "-0.5" voltage setting but just moved on to the comment up above.

3) I REALLY LIKE the Arc Fault feature and enabled it. This will detect 'bad connections' in your solar panel hookup if they are arcing due to intermittent connections. I had to decrease sensitivity by 1 number as it went off a couple of times

View attachment 25010



**Don't know how you feel about ModBus code but I have full working PHP code to read all these settings in batch for my internal DB and tracking. I didn't bother to do the 'writes' because its easy to set thru the interface. Happy to share the PHP if you want it.

This is how I get this 'low-tech' web page that refreshes every 5 secs... so I monitor the Midnites. I also parse the Batrium log every 5 mins and combine the 2 sets of data to produce this dashboard:
View attachment 25011
Thanks, lots for me to go through tomorrow!!
Your Classic has a whole different menu than mine does. Some things are similar, but I don't think mine has a lot of what your has.
 
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