EG4 Lifepower4 - Optimal Charge Settings

[MaikaiLife]

Hi All,

I recently came across a solar system configuration consisting of a 12K Sol-Ark inverter, 12 EG4 LifePower4 batteries, and a Comm Hub. The Comm Hub provides the inverter with the battery SOC and dynamically adjusts the charging amperage. The challenge, however, lies in the way the Comm Hub communicates a single voltage setting to the Sol-Ark for Bulk, Absorption, and Float stages.

The client’s goal is to maximize battery longevity by ensuring an optimal and balanced charge profile. Currently, the Comm Hub is set to 55.6V—this doesn’t trigger any alarms and all batteries are charging to 100% SOC. While there are no visible issues, this voltage may not be sufficient for proper cell balancing, which is important for long-term health and might be slightly high for floating.

The limitation is that if you set the charge voltage to 54.2V, for example, all three charging stages—Bulk, Absorption, and Float—default to 54.2V, which doesn't align with the recommended specs from the manual (see page 5). On the flip side, if you set the charge voltage to 56.2V, all three stages are locked at that voltage, which risks overcharging and prematurely aging the batteries, since they could remain at 56.2V for extended periods after reaching 100% SOC.

Complicating things further, the Sol-Ark doesn’t allow distinct time intervals for the Absorption stage. There’s no way to program a sequence like: Bulk at 56.2V, Absorption at 56.2V for 2 hours, and then Float at 54.2V. That said, the older lead-acid charging settings do allow time and voltage configuration for Equalization, which could potentially be used to simulate an absorption phase—if properly configured.

Given these limitations, I’d like to propose the following approach and welcome any feedback or alternative solutions from the community:

1. Disable the Lithium battery setting on the Sol-Ark, effectively bypassing the Comm Hub's control over charging voltages.
2. Set Bulk voltage to 56.2V.
3. Set Absorption voltage to 56.2V — note that the Sol-Ark doesn’t allow configuration for Absorption time, so this value alone likely has limited impact.
4. Utilize the Equalization setting to simulate an Absorption phase by configuring it to 56.2V for 2 hours, once every 7 days.
5. Set Float voltage to 54.2V.

The intended result is that the batteries will charge daily up to 56.2 and then a safer Float level of 54.2V. Then, once a week, the system will raise the voltage to 56.2V for two hours to help the cells balance properly, before returning to the Float voltage.

The overarching goal is to optimize battery health and longevity—ideally achieving 10+ years of reliable performance. Any insights or suggestions that could help refine this approach are greatly appreciated.

Thank you again for any input, I really appreciate everyone's participation.

 

[DougfromdaUP]

I have a sol-ark 12k with 5 Eg4 lifepower4 and that’s what I have been doing for almost three years. I didn’t think coms were worth the risk.

I have been using the equalize setting for only the last year, and not even every two weeks. I use 55.6 volts.

Edited to add that I only “equalize” for half an hour, and that works fine.

 

[MaikaiLife]

I have a sol-ark 12k with 5 Eg4 lifepower4 and that’s what I have been doing for almost three years. I didn’t think coms were worth the risk.

I have been using the equalize setting for only the last year, and not even every two weeks. I use 55.6 volts.

Edited to add that I only “equalize” for half an hour, and that works fine.

Thanks for the reply! So just to confirm—you're using the equalize function to effectively simulate an absorption phase at 55.6V for 30 minutes every two weeks?

 

[DougfromdaUP]

Yes, although I have only been doing it regularly for a couple months. They've always been balanced well, but one won't reset the SOC to 100 unless it soaks a while. It doesn't even take the full half hour, but that seems to be the shortest time you can set.