Mixing Batteries from different Manufacturers?

marionw said:

I am in a bit of a tiff with SGP over the delivery of six solar panels where two were damaged by a forklift. They offered $150.00 "compensation" for $592.00 worth of panel. I filed a complaint with SGP and also filed a complaint with FEDEX. FEDEX sent me the picture of the pallet and panels as it was just prior to loading on the FEDEX truck. (FEDEX has video cameras that point down to the lift gate area). No damage. I sent the picture to SGP and SGP's response; "Could you please let us know what compensation you need from us?" (not from Cindy but from Alisia). I will wait until FEDEX has completed whatever they do. I do hope that they (FEDEX) sends the $592.00 to SGP (which they are obligated to do) that SGP does not stiff me. The "compensation" may be a good deal on three more SGP batteries and a rack...

I may have my fingers crossed for so long it will take a pry bar to uncross them....

Once all is resolve, good or bad I will share.

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Should be a full refund!

Dinobot248 said:

A bit off topic …

I’m still bitter for paying 0.50/watt for solar panels through Amazon but I do appreciate their no hassle return.

Had to return over 15 packages, it took some effort to tape them and drive them to UPS, but the refund was seamless.

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Yeah, didn't have to return them, but that's a big reason I ordered my Renogy panels via Amazon...free shipping etc...

Something to think about - read this thread - it is long and deep but it basically comes down to a few rules for hooking batteries in parallel for even charge/discharge.

The answer isn't as intuative as most people think and the way most recommend is workable but wrong.

With the first 3 it is easy - with 4 you put the uplink cables from the bus bar to the inverter between the batteries on the bar so it pulls evenly. With 8 batteries you group them into 4 and then uplink to another bus bar with the inverter cable 1/2 way between the uplink. With more it gets progressivly more complicated but not more difficult. He lays out all the math for figuring out where to place the cables.

marionw said:

As for mixed batteries. I do have software (in development/debug/trial stage) that acts as a "Software BMS". The software collects data from each EG4 LifePower4 battery as well as each SunGoldPower battery (and a Victron Shunt). The software listens for and responds to the SGP Inverter BMS queries (there are three). The responses to the inverter represent one big battery which reflects the SOC (average) and voltage (average) of each battery in the stack. The software has the ability to fudge the data going back to the inverter to better manage battery charging.

So far trials are looking good.

One issue I am having is getting documentation for the communications between the EG4 Communications Hub (or Master EG4 LifePower4 Battery) and the EG4 LifePower4 Batteries as well as the response from the batteries. I can eventually parse/break it down but documentation ensures my assumptions are correct.

I had sent an email to Signature Solar (I purchased the Hub from then) requesting the documentation and their response; "Contact the manufacturer", I have tried that also with no response, go figure. @EG4_Jared, @SignatureSolarJess

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Let me find you some help!

Kenny_ said:

Should be a full refund!

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Let me find you some help!

Thanks. I would appreciate it after all this cannot be some "trade" secret. No secret sauce here..

SignatureSolarJess said:

Let me find you some help!

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Thanks. I would appreciate it after all this cannot be some "trade" secret. No secret sauce here..

Here is the manual to the comm hub! It shows how to connect it. I'm reaching out to EG4 to ask for any further documentation they may have!

SignatureSolarJess said:

Here is the manual to the comm hub! It shows how to connect it. I'm reaching out to EG4 to ask for any further documentation they may have!

https://eg4electronics.com/wp-content/uploads/2024/04/EG4-Communication-Hub-Manual.pdf?ref=d2992895-b100-4f5f-bcf8-ac3962d7d2f0

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I do have the manual. What I have asked for is the technical documentation on the communications data (protocol) between the Hub (or the Master BMS) and each battery. This communication is in the form of "HexAscii" where the Hub sends a command to a battery and the battery then sends a response to the hub. I can monitor and capture (sniff/spy) on the data flow but without documentation that defines all the data elements (bytes) I cannot properly decode or parse the data. I can with time and with an understanding of some of the EG4 communications protocol break it down but documentation ensures I get it right.

marionw said:

I do have the manual. What I have asked for is the technical documentation on the communications data (protocol) between the Hub (or the Master BMS) and each battery. This communication is in the form of "HexAscii" where the Hub sends a command to a battery and the battery then sends a response to the hub. I can monitor and capture (sniff/spy) on the data flow but without documentation that defines all the data elements (bytes) I cannot properly decode or parse the data. I can with time and with an understanding of some of the EG4 communications protocol break it down but documentation ensures I get it right.

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Good afternoon!

I have looked into the request and will try to get the data for the comm hub. The engineer that wrote the code for the comm hub should be in the office on Thursday and Friday this week, so bear with us until then. I can't guarantee that we can hand out that information, but I can at least ask if that is something we can share.

As far as the email, I apologize for the wait. We recently had a bit of an issue with the website update that kept a large portion of emails from coming through and once it was fixed, we have been playing catch up ever since then. Regardless of our issues, we are working on getting all emails responded to as quickly as possible.

EG4_Eric said:

Good afternoon!

I have looked into the request and will try to get the data for the comm hub. The engineer that wrote the code for the comm hub should be in the office on Thursday and Friday this week, so bear with us until then. I can't guarantee that we can hand out that information, but I can at least ask if that is something we can share.

As far as the email, I apologize for the wait. We recently had a bit of an issue with the website update that kept a large portion of emails from coming through and once it was fixed, we have been playing catch up ever since then. Regardless of our issues, we are working on getting all emails responded to as quickly as possible.

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I must say I am encouraged by the response. Exactly one of the reasons for this forum. I am sure there are others who look forward to receiving the technical data. The solar community as a whole and each manufacturer benefit from the open exchange of information that allows for improvements to products due to customer feedback.

In particular, "closed loop" communications is somewhat of a mystery and what drives the entire LifePo4 battery charging process is undocumented, from the BMS side as well as the inverter side.

Complete documentation is one key to a successful product!!!!

EG4_Eric said:

Good afternoon!

I have looked into the request and will try to get the data for the comm hub. The engineer that wrote the code for the comm hub should be in the office on Thursday and Friday this week, so bear with us until then. I can't guarantee that we can hand out that information, but I can at least ask if that is something we can share.

As far as the email, I apologize for the wait. We recently had a bit of an issue with the website update that kept a large portion of emails from coming through and once it was fixed, we have been playing catch up ever since then. Regardless of our issues, we are working on getting all emails responded to as quickly as possible.

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Some of the code would also be in the EG4 LifePower4 BMS as the BMS has to respond to the Hub's command

The Hub sends this byte array (remove dashes) 7E-32-30-30-31-34-41-38-38-45-30-30-32-30-31-46-44-32-30-0D or the ascii equivalent ~20014A88E00201FD200D to each battery.

The battery responds with this byte array (remove dashes) 7E-32-30-30-32-34-41-38-38-38-30-41-45-30-31-31-34-44-39-30-30-30-30-30-42-41-46-30-42-42-39-30-33-45-32-30-33-45-38-30-30-30-30-30-30-30-30-30-30-30-30-30-30-30-30-30-30-30-30-30-30-30-30-30-30-31-38-32-37-31-30-30-30-30-30-30-33-32-35-30-32-30-44-30-38-30-30-30-44-30-37-30-30-30-42-41-35-30-30-30-42-41-35-31-30-30-44-30-37-30-44-30-37-30-44-30-38-30-44-30-38-30-44-30-37-30-44-30-38-30-44-30-38-30-44-30-38-30-44-30-38-30-44-30-38-30-44-30-38-30-44-30-38-30-44-30-38-30-44-30-38-30-44-30-38-30-44-30-37-30-34-30-42-41-35-30-42-41-35-30-42-41-35-30-42-41-35-44-38-46-46-0D
or the ascii equivalent ~20024A8880AE0114D900000BAF0BB903E203E80000000000000000000000000018271000000325020D08000D07000BA5000BA5100D070D070D080D080D070D080D080D080D080D080D080D080D080D080D080D07040BA50BA50BA50BA5D8FF0D

Documentation would help in decoding the battery response. The response contains Battery Voltage and Current as well as individual cell voltages and 6 battery temperature readings as well as numerous alarm flags and the state of the Charge and Discharge MOSFETS and of course battery SOC

EG4_Eric said:

Good afternoon!

I have looked into the request and will try to get the data for the comm hub. The engineer that wrote the code for the comm hub should be in the office on Thursday and Friday this week, so bear with us until then. I can't guarantee that we can hand out that information, but I can at least ask if that is something we can share.

As far as the email, I apologize for the wait. We recently had a bit of an issue with the website update that kept a large portion of emails from coming through and once it was fixed, we have been playing catch up ever since then. Regardless of our issues, we are working on getting all emails responded to as quickly as possible.

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Any movement??? @EG4_Jared

@EG4_Jared No reason to believe the protocol or data is proprietary (at least I hope not).

Got some of it built. I am able to parse a significant portion of the data each battery sends back to the Hub. There are a number of bytes where each bit represents I suspect either an alarm or protection event for each cell and for the pack as a whole. I need the documentation to parse this data.

This software connects to the EG4 Hub BAT1 input and monitors for the Hub command/query to each battery. The software will build and provide a response to the Hub based on the values for each battery. Data I do not know is set to defaults.

With this screen I have six virtual batteries where I can change values and verify the values are displayed correctly on the EG4 Communication Hub LCD Screen. So far all is working.

marionw said:

@EG4_Jared No reason to believe the protocol or data is proprietary (at least I hope not).

Got some of it built. I am able to parse a significant portion of the data each battery sends back to the Hub. There are a number of bytes where each bit represents I suspect either an alarm or protection event for each cell and for the pack as a whole. I need the documentation to parse this data.

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This is some really cool stuff! Unfortunately, the information isn't available to the public yet, but I've been informed that efforts are underway to release it soon.

Progress on the Software BMS. I added the ability for Solar Assistant to connect to the Software BMS so it can see all batteries (6 EG4 LifePower4 and 3 SunGoldPower). Still a work in progress.

It is interesting however that it appears the Solar Assistant folks may have access to more EG4 protocol technical documentation than is available to the public @EG4_Jared