I had a single multi system working fine connected to my 20kwhs of PylonTech batteries. There wasn’t enough off peak grid available to recharge them from 10% to 100% over night (4hours) so I’ve installed a second Multi. I had multiple error messages last night as I tried to get everything to talk to each other and eventually managed to get it to schedule charge at 00:30. It drew 140amps which put one of my cables up to 102°c so I knocked the input ac amps back to 30amps and this reduced the DC amps to 100amps and the cable temp went down to 60°c, there was no fire risk but do need to look at the connections and / or cable size (25mm). The system recharged the batteries to 100% last night and started up this morning but the returned a #3 error, not all devices… found in the system.…and the. A low battery alarm.The system is saying the multi is not connected.
I’ve done a hard reset on the system, even powering down the batteries and it started up with the Master showing the inverting led and the slave flashing the two lights which I presume means it’s working in slave mode but with no output to the AC out 1 which my heat pump is connected onto.- I have read and watched the advanced videos on parallel systems and I did set up the master and slave via VEBus quick setup although I presumed there was only a need for one ESS assistant on the master.
- Any help would be appreciate, thanks.
I’ve saved the ESS config file and loaded into the slave Multi. I’ve also wired both units in parallel including all of he AC in/out lines. 
I’m still getting a low battery warning LED and output AC 1 is drawing from the grid rather than the batteries. 
Yes that’s a good point. I would say I ran 138amps for 30mins and had a wide temp of 102°, I scaled this back to 100amps and the temp dropped to 60°. So yes I could have damaged the batteries. The recommended charge / discharge is 50amps but this must be per unit and when connected together in parallel this for 6 batteries comes to 300amps!
I been through the videos (9.1 & 9.2) and passed the tests. I've altered the data cable to daisy chain them and disconnected the GX and then reinstalled the config set up by saving the file and loading it into the slave. Checked the connections on the batteries and changed the -ve DC cable to the end of the ring. Shut down the batteries and disconnected all cables and then restarted. Still getting an Alarm error code. In "On" mode getting 239v on AC 1 and then after a short pause 239v on AC 2.
I see that when changing the Absorption and float voltages to 52 & 51 then battery type goes blank, presumably because these values don't correspond to a particular type of battery in the library?
There was a couple of wrong values which I’ve changed:
expecting! Will see how that goes. 
