Placed an order for my first solar setup, few questions

[timaneo]

Hello!

I placed my first ever solar setup which I configured based solely on YouTube videos. After I made the order (shipped but not yet received) I found this lovely forum. Now I'd like to know if I did okay and have a few specific questions. I am a mechanical engineer but not much experience with electrical so please excuse me for any silly electrical quesitons. Thank you for any advice!

Here is what I ordered
2 x ECO-WORTHY 48V 50Ah (I want to order 2 or 4 more once I test out these first 2) Reason I picked these is they are currently half price on sale compared to EG4 rack.
1 × EG4 6000XP Off-Grid Inverter
10 x Hyperion 400W Bifacial Solar Panel

Questions
Batteries
1. If I end up with 4 of these, is it OK to parallel them directly? If I do more, is a bus bar required? What is reasoning some people suggest bus bars?
2. What wire gauge do I need for the wires that are paralleling the batteries if the wire is only 5" long between batteries. Should this be the same gauge as the 3' wire from the batteries to the inverter or less because each battery is 50ah? Signature solar told me to get 1 AWG. If that is correct should all the wire be 1 AWG between batteries and from battery to inverter?
3. I found out that the inverter requires a massive generator to charge the batteries. I do not want to get such a large generator. Is there a recommended charger that I can connect to a smaller 2000w generator that you all recommend? Cheap is fine as this is worst case; used once every 2 years scenario.

Inverter
4. Breakers: this inverter has breakers built in. Do I need any more than what is already there?
5. Saw something about resisters needed to precharge the inverter when connecting batteries. Do I need this? Or can I connect and then just turn on the breaker? If needed, what/where should I get?

Solar Panels
6. This inverter has 2 mppt controllers. Should I max out one and not use other or is there benefit to split the solar string into two and use two mppt controllers?

Thank you so much!
Tim

 

[Mattb4]

Welcome to the Forum. Someone likely will stop by and give you a bit more in depth but a couple of quick answers.

Batteries should connect to a bus bar for equal length charge path since there is more than 3 in parallel.
4awg is likely fine from the batteries (50a BMS I am guessing) to the bus bar. Go larger to your AIO.
A 2000w generator charging a 48vDC nominal battery is going to mean that at best you can use a 30a charger.

The PV array location may decide if you want to split them to the AIO's 2 SCCs. Shade conditions, split direction arrays might favor using 2.

 

[OffGridForGood]

Hello!

I placed my first ever solar setup which I configured based solely on YouTube videos. After I made the order (shipped but not yet received) I found this lovely forum. Now I'd like to know if I did okay and have a few specific questions. I am a mechanical engineer but not much experience with electrical so please excuse me for any silly electrical quesitons. Thank you for any advice!

Here is what I ordered
2 x ECO-WORTHY 48V 50Ah (I want to order 2 or 4 more once I test out these first 2) Reason I picked these is they are currently half price on sale compared to EG4 rack.
1 × EG4 6000XP Off-Grid Inverter
10 x Hyperion 400W Bifacial Solar Panel

Questions
Batteries
1. If I end up with 4 of these, is it OK to parallel them directly? If I do more, is a bus bar required? What is reasoning some people suggest bus bars?

By using a bus for Positive, and separate one for Negative you can add or remove batteries while the system continues to operate.
A good practice is to fuse each battery pos between the bus and the Pos battery terminal. Class T fuses are recommended my many on the forum for this application, or ANL fuse as a lower cost alternative.

2. What wire gauge do I need for the wires that are paralleling the batteries if the wire is only 5" long between batteries. Should this be the same gauge as the 3' wire from the batteries to the inverter or less because each battery is 50ah? Signature solar told me to get 1 AWG. If that is correct should all the wire be 1 AWG between batteries and from battery to inverter?

For your 50A batteries, an online DC wire ga calculator may spit out 6AWG for short runs, however I like to use 1 AWG to reduce heating and loses.
Auto parts stores sell short heavy battery cables typically 1AWG (and other large gauges), for low cost convenient cable supply.
Each battery is limited to 50A output, so the battery cables should be sized to at least carry this amperage each. The inverter on the other hand is another matter as follows: 6000W inverter pulling from 48v battery bank 6000/48 = 125A Your inverter needs wire capable of 125A (or higher) ie 1AWG or larger cable. I like to use 2/0 to the inverters from the bus to lower heating and line losses.

3. I found out that the inverter requires a massive generator to charge the batteries. I do not want to get such a large generator. Is there a recommended charger that I can connect to a smaller 2000w generator that you all recommend? Cheap is fine as this is worst case; used once every 2 years scenario.

Charging from a generator requires the generator output to be acceptable quality for the inverter to accept. Another way to charge the batteries by generator is to skip the 6000 input, and instead run a battery charger directly to the bus connections. The EG4 Chargeverter is often discussed on the forum for this, although lately hard to source one.

Inverter
4. Breakers: this inverter has breakers built in. Do I need any more than what is already there?

I like a fused disconnect between the solar PV and the inverter MPP inputs - a combiner box will provide this function also.
I also like to put a dedicated DC breaker between each battery and the bus connection, however this may be over-kill in your set up.
If you are powering a dedicated off-grid panel for your loads, it can be handy to have a dedicated main lug breaker to allow disconnection of the inverter from the whole panel - for doing work in the panel de-energized - for example.

5. Saw something about resisters needed to precharge the inverter when connecting batteries. Do I need this? Or can I connect and then just turn on the breaker? If needed, what/where should I get?

The inverter capacitors will take a few moments to charge from the batteries, this can be slowed by using a resistor on a separate circuit parallel to the main battery connections. Some people use the "pencil trick" - search the forum or you can buy a 50-Ohm 100W resister on amazon etc. put it on a rocker switch for precharge. Some inverters don't need a pre-charge resister.

Solar Panels
6. This inverter has 2 mppt controllers. Should I max out one and not use other or is there benefit to split the solar string into two and use two mppt controllers?

As Matt already noted, if you have some panels facing East, and some West, then you will want the East ones on one MPPT and the West ones on the other MPPT. Ditto if you have a few panels that will be shaded part of the day, put those together on a separate MPPT input from your other panels that are not shaded. (or not shaded at the same time of day).

Thank you so much!
Tim

 

[OffGridForGood]

A few separate points:
1. You show two 50A batteries to run your 6kW inverter. At max output the inverter could draw 6000/48v = 125A ie more than your two batteries together will be capable of supplying at 48v. At full charge, the batteries could be 53v, changing the amperage drawn to 6000/53 = 113A It is best not to deliberately load the inverters to full capacity, I try to limit mine to 80% or less.
2. When you select a bus bar system for the batteries, keep in mind how many batteries you will expand to in the future. ie you will want enough studs on the bus bar for all the current and future batteries together. Blue sea make some very nice ones with good holders.
3. A Shunt like the Victron 500A is a nice feature to get battery SOC information and track you system charging and discharging accurately.
4. Solar Assistant - a very simple but capable system for interaction with your new inverter via a laptop or I-Phone. I am a total SA addict and since my system is next door to my home, I run a LAN to allow me to change settings in the inverter from my living room on a laptop, rather than walking over there in the dark of winter. Some guys use Home Assistan (or both) but I don't so can't comment much on HA other than it's another option.

Welcome to the DIY forum, there is a lot you can learn here, just read and ask questions.

 

[timaneo]

Thank you @OffGridForGood and @Mattb4 !

All the advice was very helpful. I'll ordered 2 more batteries so I'll have 200A batteries to start testing the system. After looking up bus bars, it seems I can just run a bus bar directly on the terminals on all 4 batteries and avoid wires all together. This doesn't allow a fuse between the battery and bus bar like you suggested OffGridForGood but seems like I came across a lot of people running it this way, so not sure if that is required or not? The batteries have auto shut offs if anything were to happen, so should be ok?

 

[robbob2112]

Make sure to get quality bus bars, there are many on amazon that are rated far higher than their actual current carrying capacity. You can't go wrong with the blue sea ones.

 

[OffGridForGood]

I came across a lot of people running it this way, so not sure if that is required or not? The batteries have auto shut offs if anything were to happen, so should be ok?

I don't recommend a bus full of batteries without any fuse in the system. The auto-shut-offs you mention built into thee batteries is just the BMS (yes?) this will be overwelmed if you drop a wrench across the bus bars by accident. Your Set up, your property, your risk, your decision.
{what a lot of people do, is not necessarily the best advice}