Sol ark battery settings for EG4 Gyl batteries

chrisw5

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Any suggestions on what voltages I should use for the battery settings on my new Sol-Ark setup? I am running 2 - 100ah 48 EG4 batteries in parallel for battery backup. I have heard that you extend the life of your lifepo4 battery by not always charging back up to 100%

The spec sheet for the EG4 shows:
Charging voltage Rec: 58V
Rec. Bulk voltage: 57V
Rec. Float voltage: 56.5V
Rec. Absorb voltage: 56.5V

The Sol-Ark has settings for Absorb, Float, and Equalize.

Any folks out there with the same setup? Are you using the following or something else?:

Absorb: 57V
Float: 56.5V
Equalize: 56.5V (with 0 duration). My understanding the zero duration just eliminates the equalization phase.
 

smoothJoey

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Any suggestions on what voltages I should use for the battery settings on my new Sol-Ark setup? I am running 2 - 100ah 48 EG4 batteries in parallel for battery backup. I have heard that you extend the life of your lifepo4 battery by not always charging back up to 100%

The spec sheet for the EG4 shows:
Charging voltage Rec: 58V
Rec. Bulk voltage: 57V
Rec. Float voltage: 56.5V
Rec. Absorb voltage: 56.5V

This is what EG4 recommends for their battery.
I would think they know what they are talking about but it doesn't correspond to my experience.

58 volts is 3.625 per cell leaving only 25mv headroom.
Since these are good batteries with good cells I don't see this as a bad thing.
Any charge voltage at or above 3.45 volts per cell will get a battery full just takes a bit longer.

Having the absorb voltage less than the bulk voltage means little to no absorption.

I would not configure float voltage of 56.5(3.53125).
I would go no higher than 53.6(3.35).

It would be good to know how the Solark terminates the absorption phase.
Common methods are tail current or a timer.
 
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smoothJoey

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As far as charge profiles are concerned the charge current and if applicable tail current are important too.
 

robby

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I have Fortress eFlex batteries on my Sol-Ark 12K. These are almost identical to the EG4 batteries

The Settings that Fortress Power told me to use if I was not in closed loop mode was as follows.

Absorption: 56V (which is like 99.6% SOC)
Equalization: 56V
Float is off so just stick in a value like 56V

Low = 51.4V (roughly 25% SOC)
Empty = 49V (roughly 10%)
Restart = 51.8V (roughly 35%
Shutdown =50V (roughly 13%)
 

robby

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What is ^
Hooking up the batteries BMS data port to the Inverters Canbus or RS485 port and having them be able to share data. It's very useful as it allows you set charging parameters for the battery from the Inverter and vice versa the batteries can let the inverter know the true SOC numbers, voltages, currents etc.
Here is a link to explain one of the features it allows.

In the Sol-Ark you can then go into "Time of use settings" and directly let the battery know what the inverter is going to be doing during the day and night.
 

Ted Katsouras

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I have Fortress eFlex batteries on my Sol-Ark 12K. These are almost identical to the EG4 batteries

The Settings that Fortress Power told me to use if I was not in closed loop mode was as follows.

Absorption: 56V (which is like 99.6% SOC)
Equalization: 56V
Float is off so just stick in a value like 56V

Low = 51.4V (roughly 25% SOC)
Empty = 49V (roughly 10%)
Restart = 51.8V (roughly 35%
Shutdown =50V (roughly 13%)
I have Gyll batteries on my Sol-Ark 12K and I am using the same settings 56V for all states, it works fine so far. 56V is enough to reset the SOC to 100% on the BMS.
 

chrisw5

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Thanks all for the comments. Curious to know smoothJoey's thoughts on why he wouldn't go above 53.6V on float. Is that because Lifepo4s don't like to stay at 100%?

To smoothJoey's comment about how the Sol-Ark terminates the absorption phase, this except from the PV PowerView Settings guide (which gives more information than the Sol-Ark user manual) may shed some light?:

"Absorption V When the battery has recharged the absorption voltage setpoint, the Sol-Ark uses constantvoltage regulation to maintain battery voltage at the absorption setpoint to prevent heating and excessive battery gassing. The battery is allowed to come to a whole state of charge at the absorption voltage setpoint. Absorption lasts until batteries charge at 1% of the programmed Ah size. In the Bulk Charge stage, the battery is not at 100% SOC, and battery voltage has not yet reached the Absorption voltage setpoint. The controller will deliver 100% of available solar power to recharge the battery."
 

smoothJoey

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Thanks all for the comments. Curious to know smoothJoey's thoughts on why he wouldn't go above 53.6V on float. Is that because Lifepo4s don't like to stay at 100%?
I'm glad you asked.
For LFP float is like power assist.
It allows the charger to power the loads and thereby keep your battery nearly full.
53.6(3.35 per)VDC is just below the full resting voltage for an LFP battery.
Even leaving a battery sitting idle at full resting voltage is an avoidable stressor that accelerates aging.
Leaving a battery exposed to voltage above full resting is even worse.
To smoothJoey's comment about how the Sol-Ark terminates the absorption phase, this except from the PV PowerView Settings guide (which gives more information than the Sol-Ark user manual) may shed some light?:
From that description the sol-ark uses a tail current of 0.01c which is pretty low tail current.
I wonder if that is configurable.
For your 200ah LFP battery that would be 2 amps.
I would be tempted to set the absorb voltage a bit lower than the bulk voltage to effectively disable apsorption.
You can always change it back to the same value as bulk if you don't get acceptable capacity.
My WAG is skipping the absorption phase will only cost you ~2% capacity and reduce the stress on your battery.
 

chrisw5

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I don't believe there is a setting for bulk voltage for the sol-ark. I only have absorption, float, and equalization options?
 

smoothJoey

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I don't believe there is a setting for bulk voltage for the sol-ark. I only have absorption, float, and equalization options?
Different products have different terms.
The absorption parameter covers both constant current(bulk) and constant voltage(absorption) in Solark's case.
 

Koldsimer

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I don't believe there is a setting for bulk voltage for the sol-ark. I only have absorption, float, and equalization options?
It should just throw maximum current and voltage until it hits the absorb setpoint, right? That's why there is no setting for bulk
 
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