EG4 3000 with AOLithium server rack batteries and communications(RS485)

I've gone with an EG4 3000watt inverter and AOLithium's server rack batteries. The AOLithium batteries are less than 2/3 the price of going with the EG4 batteries after the taxes, shipping and other import fees here in Canada.

I'm very unclear what advantage, if any connecting up the RS485 communications between the inverter and the batteries would have.

I'm not sure they can even talk the same protocol. The AOLithium batteries seem to talk a number of different protocols. It looks like the EG4 may only talk it's own protocol?

I may just program my own controller that can talk to both and do protocol translation. Also do things like turn on the water heater when the batteries are 100% and there is excess solar production. I've got lots of experience in microcontroller programming in c. I've seen a number of different projects on git hub and such that attempt to reverse engineer some of the protocols. I'm just really unclear as to how the Inverter might use the data from the batteries. I can see lots of useful data I can poll from the inverter.

So the real question is, is it worth spending the time to program such a controller? Or maybe just a simpler project that polls the batteries for state of charge to control the water heater?

The battery protocols that are available on the 3000ehv are the following:

Li2 Pylon tech new protocol
Li3 Fox ess protocol
Li4 EG4 protocol
Li5 Pylon tech old protocol/Dyness protocol

Good to hear what you think of the AOLithium packs. You will have to play around with the dip switches to see if one of the protocols above will work.

Also make sure the communication cable pin-outs are correct for the AIO port CAN com channels. AOLithium does include a network cable but it's a standard cat5e I think so won't work. Not sure why they include it as they don't have a PC utility to monitor anyway.

EG4_Jared said:

The battery protocols that are available on the 3000ehv are the following:

Li2 Pylon tech new protocol
Li3 Fox ess protocol
Li4 EG4 protocol
Li5 Pylon tech old protocol/Dyness protocol


View attachment 203699

Click to expand...

Detritalgeo said:

Good to hear what you think of the AOLithium packs. You will have to play around with the dip switches to see if one of the protocols above will work.

Also make sure the communication cable pin-outs are correct for the AIO port CAN com channels. AOLithium does include a network cable but it's a standard cat5e I think so won't work. Not sure why they include it as they don't have a PC utility to monitor anyway.

Click to expand...

They don't include any cables included currently. I had to order the cable kits as a separate items.

Build quality on the AOLithium batteries seems to be pretty good. I have them charging from the grid at the moment and I'm going to cycle them for the first time in the next few days. I won't be installing them at our off grid property until May. I currently have a 1200watt 12v system with flooded lead acid batteries running at the property, which was big enough until my parents got Starlink and also started spending the winter there.

Standard cat5e cable will work fine for RS485 provided it's not a cross over cable. But it's not ethernet, you need something like USB to RS485 adapter to it to a PC.

EG4 made an odd choice of using a USB connector for RS485. I personally would rather see screw terminals for RS485 if they didn't want to put another RJ45 on there. At least they do supply a usb connector to RJ45 cable and one with a RS485 to actual USB adapter.

The EG4 manual references CAN in some places but doesn't have any connectors dedicated to it. There are two unlabeled RJ45 ports on the upper left side but they seem to be dedicated to linking inverters.

I'm seeing some protocols on the batteries that possibly match the EG4 inverter but it's the CAN version on the battery end.

So a protocol converter may be required. Might even be a simple as RS485 to CAN adapter. Well really not that simple given the difference in bit rates between the two.

I did find a cache of documents that has the specs for many of the protocols. That will make programming fairly easy. I just need to find the time to work on it, I have two small kids who consume all my time these days.

Oh right, they stopped including cables. For best results you can use the longer cables for each pack and cut them to length if desired to connect to the master bus bar. But... the current demand of the 3000 is likely not to be an issue even if you went with the parallel cables. The AOLithium packs support RS485 protocol but apparently only for a single pack (not master-slave) for some reason.

I would be surprised if the the 3000 does not support CAN rx/tx through the RJ45 but I don't know that unit well.

I'm wondering if anyone was able to get comms running on the EG4 with the AOlithium packs?

bbonk said:

I'm wondering if anyone was able to get comms running on the EG4 with the AOlithium packs?

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Which EG4 model are you asking about?

Finally figured this out when I read somewhere else that the EG4 3000EHV-48 was made by Voltronic. The battery manual list Voltronic protocol.

On the first battery I have dip switch 6 turned on and the left most RJ45 port connect to the "USB" style RS485 port on the inverter using the cable that came with the inverter. The second battery is linked to the first via the 2nd or 3rd RJ45 ports.

Then on the inverter I select Li2 and after a moment it starts showing the correct battery state and remaining capacity.

Was referring to the eg4 3k 48v.

LordGarak said:

Finally figured this out when I read somewhere else that the EG4 3000EHV-48 was made by Voltronic. The battery manual list Voltronic protocol.

On the first battery I have dip switch 6 turned on and the left most RJ45 port connect to the "USB" style RS485 port on the inverter using the cable that came with the inverter. The second battery is linked to the first via the 2nd or 3rd RJ45 ports.

Then on the inverter I select Li2 and after a moment it starts showing the correct battery state and remaining capacity.

Click to expand...

Thanks will try this.

EG4_Jared said:

The battery protocols that are available on the 3000ehv are the following:

Li2 Pylon tech new protocol
Li3 Fox ess protocol
Li4 EG4 protocol
Li5 Pylon tech old protocol/Dyness protocol


View attachment 203699

Click to expand...

If the 3KEHV is voltronic components and can support pylontech CAN,... does the 6500EX also?... or is LiA the only CAN protocol for that hardware?