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Any caveats to wiring the EG4/GYLL 12 or 24 in series for 24 or 48 Vdc?

PopDBop

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I'm ready to pull the trigger on a couple EG4/GYLL 24v batteries. However, I like the idea of wiring these in series if/when I want to go to a beefier 48v all-in-one inverter (e.g. Growatt), but still retain the flexibility and redundancy of two separate batteries that I can also configure in a 24v system.

Does anyone have a compelling reason why I can't or shouldn't wire two 24v in series for 48v?
 
It completely depends on the BMS.

Check the online manual or call Sig Solar.
 
It completely depends on the BMS.

Check the online manual or call Sig Solar.
True. The online manual didn't really say much. When searching for 'series' I find out that they use 'series' in the name of the battery line. Not helpful. I'll call Signature tomorrow.
 
I believe they can. I watched a YouTube video where for what ever reason a guy series wired 2 24v then parallel to one 48v. Had several banks like the then all banks parallel together.
 
I emailed Signature solar last month and they said I could run 2x 24v 200 amp battery's in series for a 48 volt system.
 
You can, but you need to charge each pack individually to 100%. Then it is safe to connect in series. Should work fine.
That makes sense, the same way it's best to balance the individual cells in a battery pack. ,

Now what about having 2 individual 24vdc charge controllers wired to charge each 24v battery individually while wired in series? Or, *must* I have a 48v charger controller to charge them in series when wired in series?
 
Is there a disadvantage with setting up a 24V system with 2X 12V EG4 batteries in series as opposed to 2X 24V in parallel?
 
That makes sense, the same way it's best to balance the individual cells in a battery pack. ,

Now what about having 2 individual 24vdc charge controllers wired to charge each 24v battery individually while wired in series? Or, *must* I have a 48v charger controller to charge them in series when wired in series?
Together, they are a single 48v battery bank. And, should be charged and discharged as one system.
 
No
As long as you treat it as a 24v battery system, from there on.
Thanks for the reply.
Actually, there is a disadvantage. I just called Signature Solar and they stated that the BMS from each 12V battery won't communicate with the 24V Growatt inverter, so we're better off getting 2X 24V and set them in parallel.
 
Thanks for the info.
Thanks for the reply.
Actually, there is a disadvantage. I just called Signature Solar and they stated that the BMS from each 12V battery won't communicate with the 24V Growatt inverter, so we're better off getting 2X 24V and set them in parallel.
 
Thanks for the reply.
Actually, there is a disadvantage. I just called Signature Solar and they stated that the BMS from each 12V battery won't communicate with the 24V Growatt inverter, so we're better off getting 2X 24V and set them in parallel.
True. But how important is that communication anyway? Even if you're using multiple 24v batts connected in parallel with the 24v inverter, is the inverter communicating with more than one battery over the serial port, and how it handling the data from multiple batteries? I seem to recall in a video that @Will Prowse mentioned that the communications was not really necessary or important with either a Growatt or MPP all-in-one.
 
It will work without communication.
It just works better with it. For the longevity of the battery, In my opinion.
I prefer to let the battery management system decide how much charging power and at what rate it will receive.
 
It will work without communication.
It just works better with it. For the longevity of the battery, In my opinion.
I prefer to let the battery management system decide how much charging power and at what rate it will receive.
Well I'm kind of new to this and just pulled the trigger on 2X 12V batteries and a 24V Growatt, but just called Signature Solar to cancel the batteries and put me on the waiting list for the 24V version.
Not sure how important this communication feature is but if it really helps with longevity, that's good enough for me.
 
Yeah, but these batteries are going to last so long (years) that by the time you even notice diminished capacity, there's likely to be new batts with even better technologies and chemistries available. Just look at what's happened to batteries and prices in the last year. Eking out even another 5% of life just seems like much adieu about nothing.
 
Yeah, but there's more to that. Without the BMS communication to the Growatt, the only information the Growatt will get as far as battery capacity is Voltage, which is highly inaccurate. In that case you'd have to get battery information some other way, like plugging your computer directly into the batteries.
In the end I guess it's just a matter of preference.
 
Yeah, but there's more to that. Without the BMS communication to the Growatt, the only information the Growatt will get as far as battery capacity is Voltage, which is highly inaccurate. In that case you'd have to get battery information some other way, like plugging your computer directly into the batteries.
In the end I guess it's just a matter of preference.
Of course. The only way to really determine state of charge is to monitor battery current as well as voltage to integrate the total charge put into the battery from a known state. So, my question is still this: in a mulit-battery system connected either in series (like I proposed here) or in parallel, which is the more likely scenario with batts rated at the nominal Growatt voltage (24, 48v) ,how does a single Growatt communicate with *both* batteries and adjust charging voltage and current from the Growatts charge controller? .

Even if the serial port allows communication with multiple batteries (I think it should work with multiple devices being a serial interface), then the Growatt still has to treat both batteries as a *single* source and adjust charging for the battery bank as a whole, yes? I view a multi-battery bank connected to a single Growatt as similar to individual cells in a LFP battery. However, in a LFP battery bank with a BMS monitoring and adjusting charge on each individual cell, the Growatt doesn't charge and balance each individual battery in the bank, but charges batteries in the bank, whether in parallel, in series, or both, as a single battery.

So, how much importance does the communication feature really affect performance and battery life since the Growatt is not charging individual batteries, but the bank as a whole?
 
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