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Can I use GEL batteries with this Growatt inverter?

CTD

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Coraki NSW
Hi, newbie here, currently have set up a 4 x 190W array through a Renogy Rover Li 40A MPPT controller with 4x 12v 100Ah GEL DiaMec batteries for my father (currently as a 12v system to run a TV and some lighting), but looking at going to larger array and double battery storage into 48V system with 12 DiaMec GEL batteries https://diamec.com/e/product/MODEL-DMD12-100-GEL-12V100AH-94.html (4 in series, then paralleled x 3) so he can run a small fridge and water pump from tank (it's a 190W water pump) as well as some small appliances occasionally, and a window air-con during the day during summer, so basically only when it is hot and sunny.

So, I have looked at the data sheet for Growatt and it doesn't mention GEL batteries specifically, so my question is, do the GEL DiaMec batteries meet the specs of this inverter? https://gwoffgrid.com.au/product/growatt-spf5000tl-5kw-48v-offgrid-inverter/
MY plan is to use 4 or 5 arrays in parallel with each array having 3 panels in series (Suntech 190W panels, Voc 45.2V, Vmp 36.6V), so around 140Voc and 115Vmp, as per the data sheet. Current per panel is 5.2Amp, so 15.6A/array, and if I go 5 arrays in parallel, that will be under the 80A max PV input. The other question I have is that it says on the data sheet that it requires 60V-115VDC for operating voltage, so does this mean that the MPPT controller will stop charging if the voltage drops below 60VDC?
Thank you for your advice.
And does anyone see any problems with this intended set-up, or is there a better configuration with what I am looking at doing?
 
Okay, a lot of problems here, first off I own 4 gel batteries and I would strongly suggest upgrading to lithium batteries as they are much better in every way. I'm pretty sure that Growatt will accept gel batteries with no problem but you can always email them to be sure. The biggest issue here is your VOC. The lower the temperature the higher your VOC goes, normally the VOC is measured around 75~ degrees, if it gets even a little cold I'm about certain that that VOC will exceed that charger's maximum VOC and fry it. I really don't see that 3 panels in a series working unless you live in an extremely warm environment, to be sure you can contact Suntech and ask them at what temperature will those panels' VOC go above 49. I know there's a good way to calculate it but I'm not super familiar with how and don't want to throw out a number when I'm not 100% sure.
 
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Okay, a lot of problems here, first off I own 4 gel batteries and I would strongly suggest upgrading to lithium batteries as they are much better in every way. I'm pretty sure that Growatt will accept gel batteries with no problem but you can always email them to be sure. The biggest issue here is your VOC. The lower the temperature the higher your VOC goes, normally the VOC is measured around 75~ degrees, if it gets even a little cold I'm about certain that that VOC will exceed that charger's maximum VOC and fry it. I really don't see that 3 panels in a series working unless you live in an extremely warm environment, to be sure you can contact Suntech and ask them at what temperature will those panels' VOC go above 49. I know there's a good way to calculate it but I'm not super familiar with how and don't want to throw out a number when I'm not 100% sure.
The gel batteries are really just a cost issue, and it would just be too expensive to get 4 Lithium batteries to get the 48V setup. As far as temp goes, this is for northern NSW area in Australia, and the coldest ever recorded temperature in this area was 0.7C or about 30F. This is the data sheet for the panels. They are probably around 10 years old now though, but seem to work fine. https://www.energymatters.com.au/images/suntech/STP190S24Adplus.pdf I don't know how to work out the temp/volt changes, but basically you are saying it's flying a little close to the limits? So, when it says that the MPPT operating voltage range is 60V-115VDC, that doesn't give me much wriggle room between 2 panels in series going below that operating voltage, and 3 panels in series risking exceeding the VOC on a cold day does it. So, I guess the next best solution is to look at a bigger (HV?) inverter?
 
OK, so what if I was to put 5-8 panels in parallel config with 2 arrays in series? It is the MPPT operating volatges range 60-115V that concerns me, as on a cloudy day the Vmp could easily (most likely) drop below the 60VDC if it's only 2 panels in series, and my understabnding is that MPPT prefer a significant higher voltage to work efficiently. So, the next best option would just be to find an inverter with higher Voc/Vmp input?
 
The gel batteries are really just a cost issue, and it would just be too expensive to get 4 Lithium batteries to get the 48V setup.
You could get one of these, it's $500 cheaper than for me to buy 4, 200ah gel batteries so it'll probably be cheaper for you: https://signaturesolar.com/eg4-lifepower4-lithium-battery-48v-100ah/
As far as temp goes, this is for northern NSW area in Australia, and the coldest ever recorded temperature in this area was 0.7C or about 30F. This is the data sheet for the panels. They are probably around 10 years old now though, but seem to work fine. https://www.energymatters.com.au/images/suntech/STP190S24Adplus.pdf
Looking at that data sheet shows that VOC was recorded at 45C That's very high and it would definitely be too dangerous to do 3 in series with that charge controller.
Voltage range is 60V-115VDC, that doesn't give me much wriggle room between 2 panels in series going below that operating voltage, and 3 panels in series risking exceeding the VOC on a cold day does it. So, I guess the next best solution is to look at a bigger (HV?) inverter?
For me, my VMP always stayed at about 100 (20.4 VMP per panels times 5 in series) even if it was cloudy. You would probably be fine at 73.2 VMP. With that being said it still might be a good option to get a different all-in-one. May I suggest this one from EG4 https://signaturesolar.com/eg4-3kw-off-grid-inverter-3000ehv-48/?ref=cPwLcVc0SW-BjN For just $750 you get a 500 max VOC, a 3000kw inverter, and a max PV input of 5000 watts.
 
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You could get one of these, it's $500 cheaper than for me to buy 4, 200ah gel batteries so it'll probably be cheaper for you: https://signaturesolar.com/eg4-lifepower4-lithium-battery-48v-100ah/

Looking at that data sheet shows that VOC was recorded at 45C That's very high and it would definitely be too dangerous to do 3 in series with that charge controller.

For me, my VMP always stayed at about 100 (20.4 VMP per panels times 5 in series) even if it was cloudy. You would probably be fine at 73.2 VMP. With that being said it still might be a good option to get a different all-in-one. May I suggest this one from EG4 https://signaturesolar.com/eg4-3kw-off-grid-inverter-3000ehv-48/?ref=cPwLcVc0SW-BjN For just $750 you get a 500 max VOC, a 3000kw inverter, and a max PV input of 5000 watts.
I am in Australia, so I don't even know if they are available over here, but I got a good deal on gels ($309 each AUD/$222 USD) so I went with them. Right or wrong, that is a done deal now. The main reason I was interested in that particular inverter was because it was an LV inverter. I can get the HV 5Kw Growatt for around $1400 AUD/$1010 USD https://gwoffgrid.com.au/product/growatt-spf5000es-5kw-48v-offgrid-inverter/ but was just hoping to keep it LV for safety more than saving the dollars, but maybe it will just be easier and safer in the end to get the bigger unit and be well within the specs.
 
I really need to find out if either of these Growatt inverters are compatible with GEL batteries first. They state lithium/lead acid/AGM?custom. I assume custom means I could manually set my charge voltages, but I will have to speak with them directly I guess, to get this information.
 
I am in Australia, so I don't even know if they are available over here, but I got a good deal on gels ($309 each AUD/$222 USD) so I went with them. Right or wrong, that is a done deal now. The main reason I was interested in that particular inverter was because it was an LV inverter. I can get the HV 5Kw Growatt for around $1400 AUD/$1010 USD https://gwoffgrid.com.au/product/growatt-spf5000es-5kw-48v-offgrid-inverter/ but was just hoping to keep it LV for safety more than saving the dollars, but maybe it will just be easier and safer in the end to get the bigger unit and be well within the specs.
In hindsight, I probably should have thought of the fact you were in Australia before sending that lol. Yeah, I don't see a way of staying with that inverter, so you'll probably have to get a higher voltage input range one. It's best you try and find one yourself because since I'm in America it will be much harder for me to find one that will ship to Australia. I think all the MPP ones ship internationally and I have one of those and can attest to how well they work. You can probably find one that's 145 VOC that would work well for about the same price.
 
I really need to find out if either of these Growatt inverters are compatible with GEL batteries first. They state lithium/lead acid/AGM?custom. I assume custom means I could manually set my charge voltages, but I will have to speak with them directly I guess, to get this information.
Yeah I would email them, I own a similar MPP all-in-one and it's fully programmable to change the charge profile so I just went with what my battery company said to go with and that's worked well.
 
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Yeah I would email them, I own a similar MPP all-in-one and it's fully programmable to change the charge profile so I just went with what my battery company said to go with and that's worked well.
OK, thanks for your help and advice. I will go with the higher Voc inputs. One last question, do you know what the difference is between MPPT Max PV charging current and Max PV input current? I assume input is the PV panel current and charging is the current being supplied to batteries during charge cycle. Is that correct? Cheers.
 
OK, thanks for your help and advice. I will go with the higher Voc inputs. One last question, do you know what the difference is between MPPT Max PV charging current and Max PV input current? I assume input is the PV panel current and charging is the current being supplied to batteries during charge cycle. Is that correct? Cheers.
Yes, that's correct. I recently found this out myself.
 
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So I've gone with this Growatt 5kw off-grid all-in-one https://gwoffgrid.com.au/product/growatt-spf5000es-5kw-48v-offgrid-inverter/ and will connect it to 12 x 12v DiaMec GEL batteries in a 48V 4 x 3 configuration. I just have to work out how to battery balance that configuration now.
Unfortunately, battery balancing is something I know practically nothing about. I would head over to the lead-acid section and ask there: https://diysolarforum.com/forums/lead-acid-batteries.20/
 
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