Ingo

The latest build V0.3 of the driver has been released.
With the new version the driver will
automatically set your battery max voltage according to the amount of cells in your battery, so it will work out of the box for 4 cells (12V), 8 cells 24V or 15 or 16 cells for 48V setups (or anything in between if your BMS can handle it. it also has an auto installer that works with a USB flash drive/SD card which means you don’t need root access anymore. https://github.com/Louisvdw/dbus-serialbattery

Probably cost. Finding a DC circuit breaker that can handle that massive amount of current is costly. The choice is yours, all installations I see use fused battery connections.

I am on my way there now. I only need two but it needs to be those small round ones.

They have a walk in store as well forgot to mention.

I just did the exact same thing to my 24V garage motor backup just the other day. I replaced the two 12V 2.4AH batteries (similar size to 60mmx80mmx175mm I think) with 8S1P 32700 batteries in a staggered configuration. I bought a cheapie BMS, 20A perhaps, and it seems to work nicely.


My next step is to get a BT BMS so I can monitor the cells remotely via my phone but before that I want to do a few Open|Close operations to see how many operations I can get before declaring this a success and leaving it in as a permanent replacement. My old batteries lasted 4 years (with a balancer) and they are still good. The LiFePo4 upgrade was just because I was bored over December 🙂 
Before installation one of the cells was slightly low but it took a few hours and they are all in perfect balance now.
So, if you like to do small projects like this then go for it, just make sure the charge voltage is enough to balance the cells and not too high to have the BMS cut off the power. Check the datasheet.
 

Try a place called electromann.co.za, saw the 18650 and 21700 holders there a few months ago

No issues, purchased items on two occasions already.

No issues, purchased items on two occasions already.

I found this useful document that describes the correct wiring of DC Circuit Breakers in PV applications.  
Discussion-Paper-Correct-Wiring-of-Double-Pole-DC-Breakers-LVL2-131210-v2.pdf

Use the direction of current flow into the switch i.e. the source side (PV in this case). You understand why you cannot use a DC CB between MPPT and batteries as sometimes the MPPT is the source and sometimes the batteries are the source. If you have a separate set of wires directly from the battery to load then you can have a CB between MPPT and batteries but then you need a CB/battery disconnect on the load cables depending on the maximum possible draw. I think you have a Victron MPPT. Some Victron MPPTs have terminals for load and others do not.
I would be inclined to have a DC CB between PV and MPPT and a battery disconnect between batteries and load. A second DC CB would be superfluous between MPPT and batteries. Just make sure your cables are specced properly. 

Essentially ACOut1 and ACOut2 are connected together when the Grid is available. It will send power out both as much as the Grid and the PV can supply.
When the Grid fails it will disconnect ACOut2 and ONLY send power out ACOut1 as much as the Batteries and PV can supply up to the KW rating of the Inverter.
 

Essentially ACOut1 and ACOut2 are connected together when the Grid is available. It will send power out both as much as the Grid and the PV can supply.
When the Grid fails it will disconnect ACOut2 and ONLY send power out ACOut1 as much as the Batteries and PV can supply up to the KW rating of the Inverter.
 

Ok, All sorted. Someone had a small piece they were willing to part with me.

The temperature sent from the GX device merely overrides the temperature reading from the Multi. The voltage compensation adjustment is still done by the Multi.
In an ESS system (not sure if you run that, probably not), the compensated charge voltage from the Multi will then be sent to the MPPTs as well (in other words, the Multi is in complete control). In a non-ESS system (aka off-grid), the temperature is sent to the solar chargers and the Multi, and each one does its own compensation depending on the coefficient it has configured (so you probably want to make them the same). But I don't see an MPPT at your site either.

OK, this was another bug fixed in Venus 2.60. I patched it in place. Try it now.

Nope, here is the setup:
No ESS, Quattro + Venus GX + Lead-Acid Battery + 1 wired temp sensor connected to Quattro + 1 wired temp sensor connected to Venus GX and then also try to add VE.Bus dongle. Dongle added with either Quattro Temps sensor alone or Venus Temps sensor alone, the VE.Bus dongle overrides either/both.
Document states any other Temp source has priority and then lists "EG. CANbus" only but my gripe is with the first part stating 'any other source' has priority. I think the person that developed the Smart Dongle code only considered CANbus to be a priority instead of all other sources as well. Possibly small oversight but impact is that I can't use the device at all.
No assistants running as my long-standing ACOut2 Relay Assistant that doesn't work on 'micro grid breaks' no one wants to acknowledge and or even look at - my peeve with a certain company's Support process (sorry).

My batteries are also bit of test case. Off-topic, but bluenova info does vary a lot - maybe because the internet has a long memory. Bluenova actually have a "customer self service portal", where you can access battery manuals etc. and the "MPS series" guide from there shows 13.9V float

any case, I will see in time what happens (and if I start messing with the charging circuits I know the magic smoke will be released from somewhere...)

I concur with the previous post and would like to add one more thing. For the Bluenova I had a chat with a support guy and he says that the absolute minimum voltage for the internal BMS to start balancing cells is 13.7V. I replaced an alarm system battery with one of these and had to modify the charge circuit a bit to get it over 13.7V, I think it was initially 13.6V for the lead-acid batteries. While doing that I increased it to 14V just to be safe and that the internal BMS can happily balance the cells when needed.

Charge the good batteries if you do have spare PV capacity and use them on a spare inverter . Use the full capacity of the batteries and then sell as scrap . I still have the 12v system I started with so the batteries get used to the last one .

Nothing bad will happen if you keep the battery monitor on. All this does is it tells the Multi to keep track of the state of charge. But...
1. You're not using the Multi's SOC anyway, so it does not matter
2. The GX device will write the battery SOC across to the Multi in any case, to keep them in sync
3. If you use any assistants on the Multi itself that uses the SOC (you don't... but if you did), you actually want this to work.
Alternatively, you can accept the 10Ah battery capacity. Again, the Ah capacity is needed so that the Multi can track the SOC... but you just told it not to, so even if that value is wrong it is not going to matter.

I must say I don't get a warm and fuzzy feeling from that breaker. Most installations I saw have one of these, either single pole or double pole if you really want to break both + and - legs. They are bomb-proof with up to 160A fuses inside and if you are unfortunate to ever see smoke where it's not supposed to be you have a large handle to pull on - no melted stuff in the DB.

I agree with this but it could be even less if the environment is not around 25 degrees C. My bank lasted, only just on 3 years in a garage that is +-35 degrees in summer and sometimes less than, and around'ish, 10 degrees C at night in winter so the life expectancy is NOT what the marketing material suggests. I am also making the leap to LiFEPo4.

Yip. It's about 10 years old and started out white and now it's a yellowish tint that stands out from the rest. That said, right next to it is a 24V transformer also from Gewiss and that one is still fine. Could be a manufacturing process with the plastic used in a certain batch of Contactors.

You can also install a steel draw wire with the pipe, The installer can then secure his wires to it and just pull the wires through. And old practice used by many construction electricians. 

One way to deal with bends and pulling cable, is put the cable in while gluing the PVC together. Saves you the effort of doing it later, especially if you don't have a good fisher tape around.