12v Enjoybot LiFePo and GroWatt AIO Inverter. Please Review and Advise

AZ Off-Gridder

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Nov 25, 2021
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Application is a fully off grid residential “tiny home”.
Proposed Battery Bank is (4) 12v 300ah EnjoyBot LiFePo batteries wired in series to reach 48v. So a 14.4kw bank.
Proposed Off-Grid Inverter is the Growatt 48V SPF 3000TL LVM – 3kW All-In-One unit.
Proposed PV Array is (16) SanTan Solar T series 250w snail trails (certified used panels). [VMP 30.3v MPC 8.27a]
Wired in series of 4 and then paralleled together (hope that wording makes sense it does in my head). 30.3v X 4 = 121.2v - 15% for used panel degradation and general loss = 103v which is well below the Growatts 145vdc max PV input. Then once wired in Parallel we get an array of 103v at 33amps = 3,407w all within the Growatts Parameters. (I think)

Questions:
1. Does anyone have first hand experience on these batteries? How are they holding up for you? I’m aware of the lack of low temp charging sensor and I don’t suspect that will affect me as this will be stored inside an insulated and climate controlled home in the desert of Arizona. But I’ve heard some less than appealing information on CHINS and some say this is the same manufacturer? Same crap new name? Or is this better quality? I know Will spoke highly of them in recent video and I value his option but he didn’t go too deep into detail on how he’s used them or what applications.

2. Will this battery bank work well with the proposed Growatt inverter? If not what’s a better option of similar price and feature?

3. Am I correct in the way I’m planning to wire my PV Array? Could I add 1 more panel to each string? The math says I could but I’d be at 132v, much closer to the 145v MAX that the inverter can handle. And should I be adding in line fuses to each string?

THANK YOU to anyone who took the time to read this!! And thanks in advance for any who offer help!
 

Bvillebob

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Oct 21, 2021
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277
I've got the same panels, a string of 3 is giving me about 105 volts, or 35 volts each. A string of 4 would be 140 volts, which is too close to your limit of 145 for my comfort. I think you're overestimating the voltage drop.
Edit, checked my logs, hit 111 volts last week with some sunshine, 37volts per panel.

With good sources of high quality cells you might look into building a real 48 volt battery. It would cost you about $2600 for 48 volts at around 300 amp hours, with known high quality parts. I've built 3 recently, it's not hard and I feel a lot better about knowing what I have and how they're built, rather than buying cheap parts someone else has assembled to maximize their profit margin.
 

WYtreasure

It's not happy hour, I'm just like this.
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Thunder Basin Wyoming
Did you plug your array
"Proposed PV Array is (16) SanTan Solar T series 250w snail trails (certified used panels). [VMP 30.3v MPC 8.27a]
Wired in series of 4 and then paralleled together (hope that wording makes sense it does in my head). 30.3v X 4 = 121.2v - 15% for used panel degradation and general loss = 103v which is well below the Growatts 145vdc max PV input"
into a calculator like this:
 

AZ Off-Gridder

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Joined
Nov 25, 2021
Messages
139
Did you plug your array
"Proposed PV Array is (16) SanTan Solar T series 250w snail trails (certified used panels). [VMP 30.3v MPC 8.27a]
Wired in series of 4 and then paralleled together (hope that wording makes sense it does in my head). 30.3v X 4 = 121.2v - 15% for used panel degradation and general loss = 103v which is well below the Growatts 145vdc max PV input"
into a calculator like this:
What an awesome tool! Thanks you this is my first time seeing this tool and it gave some great detailed information. Maybe I should look into other inverter options with higher max PV voltages. I really like the simplicity of the all in ones and I’ve had one in the past it was great. But they do have limitations, they sell ones with higher PV voltage but seems the price jumps up a lot.
 

AZ Off-Gridder

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Nov 25, 2021
Messages
139
Now I’m looking at the MPP LVX6048 it’s a bit more expensive but for the price you get a lot more out of it compared to the 3kw Growatt. Direct from the manufacture website says max VOC is 600v but on Watts247 website says max PV is 450vdc still a lot higher then Growatts 150vdc so I would have more options on how to wire the panels, more series capabilities. Seems like the better route am I correct? Is there any particular reason to keep the number of series down? I know when getting into many parallels you can create situations where more and more over current protection devices become necessary. Is there anything similar I should be worried about when going the other way and having more and more in series? Looking to order a unit within a few weeks so I want to be set on one and for the right reasons. My use is 110/120 power only no need for 220/240.
 

Bvillebob

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Oct 21, 2021
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277
The only concern is that high voltage DC is dangerous as heck. I've worked with HV all my life, been hit with 6KV before, woke up across the room with the smell of barbacue in the air...I run my panels at 100-110 volts, anything much higher than that personally I start getting nervous. I know some systems run 300-500 volts, no mistakes allowed at that voltage.
 

AZ Off-Gridder

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Nov 25, 2021
Messages
139
The only concern is that high voltage DC is dangerous as heck. I've worked with HV all my life, been hit with 6KV before, woke up across the room with the smell of barbacue in the air...I run my panels at 100-110 volts, anything much higher than that personally I start getting nervous. I know some systems run 300-500 volts, no mistakes allowed at that voltage.
How many parallels are you running and what sort of overcurrent protection are you using? In line fuses? The last time I did a solar set up it was only six panels this time around there’s a lot more to consider because it’s on a larger scale of 16 or more panels
 

justgary

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Jan 1, 2022
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As for panels and age, I have a small panel that I removed from service after about 15 years and tossed in the pile out back. About a year later I decided that I needed a small panel to run some DC fans, so I pulled it out of the pile and tested the open voltage and closed current on a nice sunny day. It still produced very close to the specified parameters listed on the back. I was shocked (if you can excuse the pun).

I don't think they really age like they expected them to all those years ago.
 

coolbz

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Jul 25, 2021
Messages
88
Now I’m looking at the MPP LVX6048 it’s a bit more expensive but for the price you get a lot more out of it compared to the 3kw Growatt. Direct from the manufacture website says max VOC is 600v but on Watts247 website says max PV is 450vdc still a lot higher then Growatts 150vdc so I would have more options on how to wire the panels, more series capabilities. Seems like the better route am I correct? Is there any particular reason to keep the number of series down? I know when getting into many parallels you can create situations where more and more over current protection devices become necessary. Is there anything similar I should be worried about when going the other way and having more and more in series? Looking to order a unit within a few weeks so I want to be set on one and for the right reasons. My use is 110/120 power only no need for 220/240.
The issue with long series is that a tiny shade on one panel will greatly reduce your overall wattage. This is from my experience.
 
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