Hi,
I could build a LFP battery, but was unsure how to get an inverter and a charger to work in ESS harmony. Then googling around I bumped into the Multiplus II and CerboGX, thus realizing this whole design was not only commercially available in a neat package, but was actively supporting DIY ESS, going as far as releasing Venus software as open source. Honestly I was stunned, this is my first experience of a hardware commercial company choosing such an open approach - I’m guessing it might be a legacy of empowering off-grid customers who require complete autonomy in controlling their setup. Geez, even the documentation has a tone and sense humor I’ve not seen anywhere else 
I spent more than I had planned on the inverter/charger, because of the very specific open approach.
Anyways, I’ve been happily running a MP II based ESS since last summer :
MP II 48/3000 with ESS assistant, Venus on raspberry PI2, 100A JK-BMS with dbus-serialbattery connection, 16 x Eve 280 Ah LFP, array of 7 second hand PV 250 Wp panels / 4 APS YC500I micro-inverters, grid meter Shelly EM50 via MQTT.
Where does the power supply from the Raspberry come from? from the Multi? if it has to restart, your connection would be lost …
Nice cover for the small PE rail. 
Those are trained eyes 
Since the picture was taken, the raspberry is now powered from a DC 48V to 5V converter connected to the battery (with inline 5A fuse). Would update the picture, but the enclosure is very crowded with a mini fan heater (close to freezing here in Provence) and an unrelated file backup system (provides some secondary heat too)…
Still can’t get over noticing the PE rail insulator.
Then I hope that the Multi doesn’t hum so much on the wood … 
Nice little system … 
PS: simply build a false bottom over it …
I have to admit the humming is quite noticeable - luckily in outside shed so no nuisance, but way too cold in winter and a little too warm in summer 
Hello Pascal,
can you share your inverter and charger values (like dc shutdown /restart / alarm and absorption volt / float…) in the ve configure for your 16s 280ah battery.
That would help me a lot as i have more or less the same configuration.
thanks,
Hi Olivier,
Please find below a copy of my current MP2 parameters. It took a number of setting trials to settle on these, but I’m pretty sure some could be further optimized. I relied on the Eve LF280K and BMS specs to try and set the relevant parameters, please adapt to your batteries and equipment. Also note that my solar inverters on MP2 AC critical out are not able to throttle their output via AC frequency shifting, so I’ve pretty much disabled this feature in my parameters. I’ll have to revise this when I increase solar capacity.
One thing I learned the hard way, is that on commissioning your ESS, you should force your battery storage through a full cycle, especially aiming for a full charge. You need to keep an eye on each cell voltage (via the BMS usually), looking for the tell-tale sudden increase in the voltage slope. This will let your BMS set the voltage for an estimated 100% SoC (as well as let effective cell balancing kick in, I admit only understanding recently the reasoning behind top balancing). Having so much extra amp.hours, and high cell voltage being a source of premature aging, I had avoided this full cycle when commissioning my ESS, with the result that what I thought was “60%” SoC was in fact much lower, with cells operating at pretty low voltage for 5 months, this in turn leading to unexpected low batt warnings… So much is dependent on reasonable SoC estimates, I’ve seen so much excellent advice around setting up an ESS system, and I read as much of it as I could, but I must have missed the parts mentioning the importance of fully cycling the ESS to set realistic SoC estimates.
I welcome any suggestions concerning the below parameters 
TAB: General
System frequency 50Hz
Shore current 32.0 A
Overruled by remote checked
Dynamic current limiter unchecked
External current sensor connected (see manual) unchecked
State of charge when Bulk finished 95.0 %
Battery capacity 280 Ah
Charge efficiency 0.95
TAB: Grid
Country / grid code standard France: VDE V 0126-1-1 VFR 2019
AC input 1 Above selected gridcode plus LOM B (compliant)
TAB: VFR 2019 grid code settings
Use Aux1 as disable FeedIn signal unchecked
Maximum AC current for charge or feed in 100.0 %
Maximum generated apparant power 100.0 %
connect waiting time 60 s
connect power ramp 0.0 seconds
low frequency connect value 47.500 Hz
high frequency connect value 50.100 Hz
low voltage connect value 85.00 % Un
high voltage connect value 110.00 % Un
re-connect waiting time 60 s
re-connect power ramp 600.0 seconds
low frequency re-connect value 47.500 Hz
high frequency re-connect value 50.100 Hz
low voltage re-connect value 85.00 % Un
high voltage re-connect value 110.00 % Un
rise-in-voltage protection U> 110.00 % Un
under voltage stage 1 80.00 % Un
under voltage stage 1 delay 0.00 s
over voltage stage 1 115.00 % Un
over voltage stage 1 delay 0.00 s
under frequency stage 1 47.500 Hz
under frequency stage 1 delay 0.00 s
over frequency stage 1 51.500 Hz
over frequency stage 1 delay 0.00 s
under voltage stage 2 79.00 % Un
under voltage stage 2 delay 0.20 s
over voltage stage 2 116.00 % Un
over voltage stage 2 delay 0.20 s
under frequency stage 2 46.000 Hz
under frequency stage 2 delay 0.00 s
over frequency stage 2 54.000 Hz
over frequency stage 2 delay 0.00 s
P(f>) start frequency 50.200 Hz
P(f>) stop frequency 50.200 Hz
P(f>) start delay 1.50 s
P(f>) stop delay 1.50 s
P(f>) droop 5.00 %
P(f<) start frequency 45.000 Hz
P(f<) stop frequency 45.000 Hz
P(f<) start delay 0.00 s
P(f<) stop delay 30.00 s
P(f<) droop 5.00 %
P(U) response Not used
Reactive power regulation Use a fixed Cos Phi
Filter time for reactive power 3.0 s
Cos phi 1.00
Use lock-in/out unchecked
TAB: Inverter
PowerAssist unchecked
Inverter output voltage 230 V
Inverter DC shut-down voltage 47.00 V
Inverter DC restart voltage 50.00 V
Low DC alarm level 49.00 V
Do not restart after short-circuit (VDE 2510-2 safety) unchecked
enable AES unchecked
TAB: Charger
Enable charger checked
Weak AC input unchecked
Stop after excessive bulk unchecked
Lithium batteries checked
Disable VSense (for diagnostic purposes) unchecked
Configured for VE.Bus BMS unchecked
Charge curve Adaptive
Absorption voltage 56.00 V
Float voltage 54.50 V
Charge current 35 A
Repeated absorption time 1.00 Hr
Repeated absorption interval 7.00 Days
Maximum absorption time 8 Hr
TAB: Virtual switch
TAB: Usage
Virtual switch usage Do not use VS
TAB: Assistants
TAB: Assistant Configuration
ESS (Energy Storage System) (size:1800)
*) System uses LiFePo4 with other type BMS
(This can be either a BMS connected via CAN bus or a BMS system in which the
batteries are protected from high/low cell voltages by external equipment.)
*) The battery capacity of the system is 280 Ah.
*) Sustain voltage 48.00 V.
*) Cut off voltage for a discharge current of:
0.005 C= 50.00 V
0.25 C= 49.00 V
0.7 C= 48.00 V
2 C= 47.00 V
*) Inverting is allowed again when voltage rises 1.50 V above cut-off(0).
*) Restart PV Inverters when the DC voltage becomes lower than 53.00 V.
*) The solar converter will start reducing its output power at 51.20 Hz.
Output power will be reduced to minimum when the frequency is 52.00 Hz.
The converter will disconnect when the frequency is higher than 53.00 Hz.
*) Total installed PV inverter power is 1800 Watts.
Total installed PV panel power is 1800 Watts.
*) Relevant VEConfigure settings:
- Battery capacity 280 Ah.
- PowerAssist unchecked
- Lithium batteries checked
- Dynamic current limiter unchecked
- Storage mode unchecked
Total size of all assistants including the required
(hidden) system assistants is: 1873
TAB: Advanced
limit internal charger to prioritize other energy sources unchecked
I was thinking about using 4 rubber feet, used for AC outdoor units, as isolators. What do you think? Would that work?
Also. What type of white switch is that on the left? Something from Schneider Electrics?
I hope you have some space on the back of the BMS, because that metal plate has to cool some FET’s too.
My preference goes to fire resistant material inner layer like “cement fiber board” or so
I agree with #stopburningstuff sentiment! I live in the USA where fossil fuels have an iron grip on the American psyche. cement fiberboard is one approach, but we have found that using fire-rated plywood is a much easier solution. My father in law has been a licensed electrician for 50 years and that’s what he suggested we use for high-power electronics. If we’re going for a show-worthy display then we’ll wrap the fire-rated plywood with a black marine carpet that doesn’t burn. It will melt, but doesn’t catch fire.
Sorry for the delay in replying.
I doubt rubber feet will change much about the noise, the vibrations appear to come from the unit rather than from any transmission to the support.
The switch on the left is a bypass switch in case I need to connect the critical AC load direct to the mains (cabling yet to be completed for this switch).
Good point, maybe I should slide some M0 sheet material behind the BMS, and some taller spacers. Glad to report that no smoke over the last 8 mo operation, I do have a smoke detector right in there only a few inches away from any of the parts of the setup.
FET’s are not that smoky, they just stop working
No problem. Life happens here as well. Copy that.
Another thing I noticed. If I’m not mistaken. You don’t seem to have anything, like epoxy sheets, in between your prismatic cells?
Geez I never cease to be impressed by the keen eyeballing around here 
I don’t have the classic epoxy sheets between the cells indeed, instead I have 1.5mm thick clear PVC that I cut out from the same material as you can see covering the cells (for see through insulation). I also reckoned the fairly thick yet flexible PVC spacers may provide some elasticity for those cells to expand a little).
Haha. Oops. Sorry
Oh but that PVC sounds like a great alternative to the epoxy sheets.I myself use a soft rubber layer at the sides and the bottom. The idea was to add some kind of insulation, but if that actually works 