Adding second EG4 LL

[xy74]

I currently have a single EG4-LLv2 battery on my system and am about to add a new EG4-LL-s.

1) When I add the second battery, should they be at the same SOC roughly?

2) I am not currently using any communications to the Victron MPPT or the Morningstar inverter. If I just connect the 2 batteries with the comm cable, will they talk to each other and work automatically together? Do they need to talk to each other?

3) Will I need both on the same firmware? Saw there was an issue with v1, but will v2 be OK?

 

[teal95]

You're not the only one doing this, I am as is at least one other person. They asked similar questions in the last couple days. I joined in. I had the same question on SOC and the answer as I remember it was it's not critical with the flatness of the voltage curve.

I'm planning on hooking the comms all together to the first rack.

I hadn't thought about updating the firmware but I wouldn't be surprised if that is necessary to get them to talk together. How old is your older batts? Mine are from November...

 

[xy74]

Older battery is August.

 

[RxJemm]

Agreed.

With the 48V version of the EG4-LL no longer listed on SS' site, I think there needs to be some clear guidance / video on this. Those of us adding to our existing LL v2 bank would love to know what firmware choices etc , need to be made.

Perhaps a youtube video and / or manual page entry?

Thanks !

 

[RxJemm]

This page does not mention the V2's need for new firmware. Perhaps the latest on EG4's site will work ?

 

[xy74]

I guess I will see how it works out and if the 2 batteries will stay more or less evenly charged once it's all hooked up. New battery won't be along until Monday and I won't be down to the cabin until later in the week. I'm also wondering since there is no "system" connection in mine, does that matter as far as the inter battery communication. DIY and FIOY (Figure It Out Yourself)

 

[marionw]

I don't believe that battery to battery communications allow batteries to control their individual charge or discharge with respect to each other so that all batteries remain balanced. In addition the "Master" battery does not control the charge/discharge of individual batteries in the battery stack (would be nice if it did).

There are several reasons to connect battery to battery communications with one battery designated as "Master":
1: You intend to use "closed" loop communications. The "Master" battery communicates battery data collected from all batteries to the inverter as "One Big Battery"
2: For many battery models, battery to battery communications is required for the software provided by the battery manufacturer to monitor all batteries with the computer plugged into the "Master" battery or a shared RS485 port.
3: For some batteries you need to have a "Master" to monitor all batteries with computer software or Solar Assistant where the battery provides a port specifically for monitoring.
4: For some batteries you do not need a "Master" when operating in "open loop" and you can connect a computer or Solar Assistant to the port normally used by the inverter.

 

[xy74]

Apparently they are talking and getting along with each other, SOC, loads, and charging current stay pretty close. I set the dip switch on the newer battery as 1 and something higher on the older battery. Using whatever firmware they came with.

 

[EG4_Jared]

Apparently they are talking and getting along with each other, SOC, loads, and charging current stay pretty close. I set the dip switch on the newer battery as 1 and something higher on the older battery. Using whatever firmware they came with.

A firmware update or removing pin 6 on the communication cable between the LL-S to LL-V2 would be needed.

 

[xy74]

A firmware update or removing pin 6 on the communication cable between the LL-S to LL-V2 would be needed.

I did neither. Is there any way to tell they are or are not communicating? How do you tell what firmware it has?

 

[EG4_Jared]

The best way to tell is by utilizing BMS Tools.

Here is a video going over this:

 

[xy74]

Hmmm, I would have to think about whether a root canal or fiddle with that would be less painful. Probably the root canal. I'll have to look into getting a cable, contrary to what the video says they do not come with a USB cable from SS.

The more I think about it, the least painful move might be throw the comm cable in a box and go on with life. I can't see any reason aside from troubleshooting that I would ever care about any of the stuff he was looking at in the video. Same with the features marionw mentioned (TY). I guess being a relatively old guy, I just expect a battery (or 2) to just provide some power. They seem to be doing that pretty evenly as they are now.

 

[SignatureSolarJess]

Hmmm, I would have to think about whether a root canal or fiddle with that would be less painful. Probably the root canal. I'll have to look into getting a cable, contrary to what the video says they do not come with a USB cable from SS.

The more I think about it, the least painful move might be throw the comm cable in a box and go on with life. I can't see any reason aside from troubleshooting that I would ever care about any of the stuff he was looking at in the video. Same with the features marionw mentioned (TY). I guess being a relatively old guy, I just expect a battery (or 2) to just provide some power. They seem to be doing that pretty evenly as they are now.

I'm so sorry if your unit did not come with a cable! It seems that some of the units we recieved did not have them included in the boxes If you'd like to reach out to me directly, I can get you one ordered and sent out promptly!