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Electrodacus- can it be this simple?

Furthermore, if you just use the SBMS0 to turn the MPPT on and off, you already have two levels of protection.
You may want to call it two levels of protection, but it is not fault tolerant. A single point failure can still bring down the batteries. The setup I described is fault tolerant.
 
Why do you need the bolded? The CC will shut down if input PV is less than Vbatt+5V in the case of a Victron; and no point I can see to do so at a different voltage point?
We're not concerned if PV is less than Vbatt + 5V. Our concern is of overvoltage conditions. If the CC becomes defective (for instance the pwm transistor shorts) then the battery will overvoltage. We would like a second line of defense, like a relay between the panels and the CC. The BMS monitors for overvoltage and will open the relay. All is safe!
 
So, I've been tallying up the costs for my two system options and it's remarkably close.
It's more than likely that I've forgotten or misunderstood some of this of course- corrections and advice, as always, very welcome!

1: Electrodacus based.
SBMS0, 4xDSSR20, two shunts, 600w panels at 12v, Victron BP 100A.

2: Overkill based.
Overkill BMS, Aili battery monitor, 600w panels at 32v, 60A MPPT

In both cases, there will be an inverter which is controlled by hacking the switch and wiring this directly to the BMS. I'm pretty sure this will work for the SBMS0, less sure about whether the Overkill can do it. I haven't bought the inverter yet, but the one I have my eye on appears to operate via a rocker switch.

The Overkill system is coming in a little cheaper, but there's not much in it. At the moment my gut feeling is swaying towards the Electrodacus, because I think it provides better overall control and protection, and will prove more adaptable.
 
Finally heard back from solar panel supplier. I'm being offered a refund, which means I could start again and go 12v. Or stick with the order, not that I am very impressed with the supplier right now. I chose these panels because they are relatively low weight, which is of some importance when mounting them up high on a boat. If I switch to multiple 12v panels I will lose that advantage, but it makes the SBMS0/DSSR20 system make more sense. Yeah I'm not great at making decisions sometimes :D

Question: is a 12v system using Electrodacus honestly able to compete with MPPT for efficiency? I have heard that it is highly efficient, and the components will last longer, but I don't really see how it works. Without a way of boosting the panel voltage how do you ensure that you can always reach a high enough voltage to be able to charge your batteries?
 
Is the DSSR20 as efficient as an MPPT with 12 volt panels paralleled? no....But not by much making it hard to justify the extra expense. (at least for me) Will 12 volt panels charge a 12 volt battery, unless you have a ridiculise line loss YES.
 
Question: is a 12v system using Electrodacus honestly able to compete with MPPT for efficiency?
What are the specifications of the panels? I've measured 5% higher efficiency of mppt with 12V panels.
 
Hmmm. Food for thought. Seeing as I will be using a separate SCC anyway, maybe the Electrodacus isn't the best fit.
Would I be correct to think that either Electrodacus or Overkill can command relays (or other switching devices) on both charge sources and loads. And so the Overkill does the same job but with a 100A FET switch already onboard.

All else being equal, I would definitely prefer a dedicated display for battery charge state. I have a terrible habit of losing my phone...
The Electrodacus can turn off most Victron solar charge controllers without using a contactor or SSR as well. Dacien has this well documented.
 
The Electrodacus can turn off most Victron solar charge controllers without using a contactor or SSR as well. Dacien has this well documented.
Thanks. I'm trying to keep the budget down and was hoping to go Epever rather than Victron. It's a pretty big price difference.

Actually the more I look in to things the more I think Overkill is the way to go for me. I really really like the Electrodacus concept but having to stick with 12v solar panels is a bit of a drawback (and yes, I could combine the SMBS0 with MPPT but then the cost jumps, a lot).

I should probably start a new thread for the Overkill plan, but from what I've learned so far the biggest headache with that route is finding a way to protect the MPPT. Of course with a cheap Epever unit I could just take the risk, it's £130 which represents about 10% of the total system cost.
 
I use the Dacus on a small 12v system and I’ve been following the Electrodacus forum for bout 2 years. I followed the path the Dacus needs and never had an issue. The only issues I’ve seen on the forum are when someone trying to play outside the Dacus sandbox adding stuff that the Dac already does.
 
The CC will shut down if input PV is less than Vbatt+5V in the case of a Victron; and no point I can see to do so at a different voltage point?
Actually it will not shut down below a 5 volt difference in voltage between the PV and battery. It is true that Victron controllers need the 5 volt difference to start but they will continue working until the panel voltage is 1 volt above battery voltage.
 
I think it might only be certain models of Victron which can be directly controlled by the SBMS0?
All Victron solar controllers can be controlled by the SBMS0. The larger ones directly and the smaller ones with a VE Direct cable.
 
Actually it will not shut down below a 5 volt difference in voltage between the PV and battery. It is true that Victron controllers need the 5 volt difference to start but they will continue working until the panel voltage is 1 volt above battery voltage.

Thanks for pointing that out.
 
Actually it will not shut down below a 5 volt difference in voltage between the PV and battery. It is true that Victron controllers need the 5 volt difference to start but they will continue working until the panel voltage is 1 volt above battery voltage.
Thanks, that is good to know.
 
OK.... The moment you start talking about a 3K inverter, it is not a small system any longer.

Here is a design I recently did for a gentleman from Florida that built it and is now exploring the South West in his RV.

View attachment 44566


The design is more than you need. Here is a simplified version that is closer to your needs:
View attachment 44568

You would want to tweak it to match your needs. Also, If you don't like the DSSR20 that goes with the Electrodacus SBMS0, you could use a Victron SCC..

I attached a PDF of the two drawings as well.

Finally, if you are putting it on a boat.... don't cheap out on the equipment. Get marine grade or it won't hold up.
This has been an incredibly helpful thread, especially the above diagram. This finally helped me visualize everything needed in a setup with an electrodacus bms. I have 8 280ah eve cells on the way and am trying to select a bms. I have a victron multiplus 3000 and mppt as well as a venus GX controller running now with a single 12 v 300 ah lithium battery, that I intend to replace with the 8 eve cells. So I think I am choosing between and an electrodacus set up as above with cells configured 2P4S, or configuring the 8 eve cells as 4S2P with two JBD 150a bms, which sounds a lot simpler? Don't expect to ever need more than 200 A and usually less than 100 A.
 
This has been an incredibly helpful thread, especially the above diagram. This finally helped me visualize everything needed in a setup with an electrodacus bms. I have 8 280ah eve cells on the way and am trying to select a bms. I have a victron multiplus 3000 and mppt as well as a venus GX controller running now with a single 12 v 300 ah lithium battery, that I intend to replace with the 8 eve cells. So I think I am choosing between and an electrodacus set up as above with cells configured 2P4S, or configuring the 8 eve cells as 4S2P with two JBD 150a bms, which sounds a lot simpler? Don't expect to ever need more than 200 A and usually less than 100 A.

Same here. I had bought an Electrodacus BMS, a while ago, but not gotten to connecting it yet. Now, new boat, new electrics, I plan using it, using filterguys design.
See the following
 

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OK.... The moment you start talking about a 3K inverter, it is not a small system any longer.

Here is a design I recently did for a gentleman from Florida that built it and is now exploring the South West in his RV.

View attachment 44566


The design is more than you need. Here is a simplified version that is closer to your needs:
View attachment 44568

You would want to tweak it to match your needs. Also, If you don't like the DSSR20 that goes with the Electrodacus SBMS0, you could use a Victron SCC..

I attached a PDF of the two drawings as well.

Finally, if you are putting it on a boat.... don't cheap out on the equipment. Get marine grade or it won't hold up.
 
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