Wiring Diagram - 2x 60 Cell Used Panels - 12/24v

Here are a list of parts that will enable you to build the solar charging piece of this diagram. You will spend $250-$300 on wiring and charge controller in addition to the panels, battery, and inverter you choose to use. This setup over-panels the 60 Amp charge controller by 240 watts, which is acceptable as this controller will limit the current to 60 amps and simply not use the excess wattage assuming it’s available. One will not typically get 100% efficiency from a panel due to sun angle, clouds, heat, etc. that are always a factor. Making the over-paneling reasonable.

 

Make sure you grab two MC-4 inline fuses, as you’ll want one per string of panels.

Devices:

Supplies:

Tools:


230AH Eve LiFePo4 Cells For Sale

New Grade A 230 AH LiFePo4 Lithium Cells For Sale in Mansfield Texas

These are brand new Eve LiFePo4 cells ready to be built into a battery pack. Great for solar storage in cabin, rv, portable setup, etc.

These have never been cycled. Include bus bars and nuts/studs.

I can provide 100/120A Bluetooth BMS for $120 (12v, 24, 36, 48v available). This includes low temperature cutoff.

Four of these cells will make a 2.9Kwh 12v pack. Or 16 in series for a 48v 11.5Kwh monster!

Each box of four cells is priced at $590 with the following quantity discounts:

4 cells (12v) $590
8 cells (24v) $1100
16 cells (48v) $2080

 

If you’d like a battery already put together I can do it at the following price points:

$950 12v 2.9Kwh

$1400 24v 5.8Kwh

$3000 48v 11.5 Kwh

Electrical Specs:

  • 230AH
  • 3.2V Nominal
  • 230A Max Continuous Discharge/Charge Rate
  • Cycle life @25C >= [email protected]

Physical Specs:

  • 2.12″ Thick
  • 8.16″ Tall
  • 6.85″ Wide
  • 9lbs Each Cell
  • 6mm Studs pre-welded to each terminal
  • Bus bars and nuts included

Full Spec Sheet

Warranty:

1 year warranty, will refund/replace depending on availability.

Shoot me a text or call me, Christopher, at (682) 730-0725 for more information.


230 Watt Astronergy Solar Panels For Sale

Used 230 Watt Solar Panels For Sale in Mansfield Texas

These are used panels that were recently pulled from a large solar installation. Panels are in perfect condition despite being 8-10 years old. Original labels are in-tact making these permit able for grid-tie installation. We are offering these for sale out of our Mansfield, TX warehouse. Unfortunately shipping is not available for these panels.

We have a few hundred available right now.

Each panel is priced at $58.

Electrical Specs:

  • 230 Watt
  • 37 Voc
  • 29.81 Vmp
  • 8.43 Isc
  • 7.69 Imp
  • Max Series Fuse 15A

Physical Specs:

  • 39.25×65.125×1.77″
  • 44lbs
  • MC-4 Male and Female connectors with ~3′ leads

Warranty:

No Manufacturer warranty, Beene Brothers will replace or refund within 1 year for non-working panels as long as they didn’t fail from misuse or abuse.

Shoot me a text or call me, Christopher, at (682) 730-0725 for more information.


Small Backup System: 1.2KWh

With 400W of Solar and a 1.2KWh battery this setup with the right sun exposure can run a full sized refrigerator indefinitely. Wouldn’t hurt to do 2 panels instead of 1 to account for clouds but if you need something to keep the food fresh the next time the power goes out this could be your ticket.


Advantages

  • Large enough battery to run some appliances indefinitely
  • Lithium (LiFePo4) battery that should last 3000 cycles or more
  • Will handle up to 720W of solar panels

Disadvantages

  • Inverter is 1000 watts, could be undersized for running additional appliances.
  • At 12 Volts if you are planning on a larger system in the future it will be harder to manage the wiring as it gets thicker to handle more load. 48 Volts is a sweet spot if you intend to run a cabin off solar as it brings the wire size down to a reasonable gauge.


Some of the pricing here is from other sites out of our control, with a single 395W Solar Panel expect this setup to cost about $1020. We are assuming the solar panel would be mobile and have not included any mounting hardware. Check out the RV build for some Z brackets that are heavy duty enough to handle these full size panels for installing on a roof such as your shed.

Beene Brothers strives to keep this in stock for $100 as a convenience. If we don’t have it available, Amazon and Aliexpress should be able to set up you with a unit.

This battery is put together by us here at Beene Brothers Solar. It is made up of brand new LiFePo4 Prismatic Lithium cells assembled with finger-screw battery terminals to make this portable battery easy to operate.

  • Continuous Load Output: 80 Amps
  • Recommended Charge Rate: 50Amps
  • Maximum Capacity: 1.28KWh
  • Life Expectancy: Greater than 2000 Cycles
  • Weight 26.4 Pounds
  • Cost: $450
Count Item Cost
1 3 Feet of Red Double 10 Gauge wire for Charge Controller to Battery $4.50
1 3 Feet of Black Double 10 Gauge wire for Charge Controller to Battery $4.50
2 30 Feet of black PV Rated UV Resistant 10 Gauge Wire for Charge Controller to Solar Panels $30.00
1 15 Amp MC4 Fuse for Solar Panels $20.00
2 30 Amp Fuse Holder for Battery Positive Cable $6.00
1 Pair of MC4 Connectors $3.00
1 Crimping and Heat-Shrinking Wires $30.00
Total Misc. $98.00

6KW Grid Tie Solar On a Budget

As long as you are willing to hire your own electrician or even install everything yourself the parts for grid tie solar are not expensive! Here are some pieces that can be used to build a system that should be well under $1 per watt if your racking isn’t very expensive.

 

For racking what I did was spec out the system at ironridge.com and then take the generated Bill Of Materials over to www.ressupply.com to purchase. the prices were half or less than MSRP and shipping was a flat $150.

 

Check out the parts list below for other pieces and suggestions on quantity for a very nice 6kw system.




MPPT vs. PWM Solar Charge Controllers

The Difference Between MPPT and PWM Solar Charge Controllers

Solar charge controllers are an important component of any solar power system that utilizes battery storage. The controllers help to regulate the flow of power from the solar panels to the batteries. If batteries are overcharged, their life is usually reduced significantly. In some instances, it could cause damage to the batteries, rendering them unusable.

Modern solar controllers also help to prevent the reverse flow of current. At night, when solar panels are not producing electricity, batteries can lose power as it flows back towards the solar panels. The controllers detect when solar panels are not producing power and they disconnect the batteries from the solar panels.

If you are planning to purchase a solar system, you will have two options when picking a solar controller. These are the Pulse Width Modulation (PWM) and the Maximum Power Point Tracking (MPPT).

The Pulse Width Modulation (PWM) Controllers

PWM solar controllers are the standard type of charge controller offered to solar system shoppers. These controllers work by slowly cutting back the amount of power being sent to the batteries as they reach full charge. When the battery bank reaches full capacity, the PWM controllers maintain a trickle of power. The result is that a small amount of power continually keeps the battery bank full.

PWM controllers work when the solar array and the battery bank need to have matching voltages. In large systems for powering the entire home, the battery and panel voltage are not usually the same. As a result, PWM controllers are most appropriate for small DIY systems.

For instance, a 12V panel will charge a 12V battery. If you have a 24V battery bank, you will need a 24V solar array. If you attempt to charge a 12V battery with a 24V solar array, over half of the power from the solar panels will go to waste. On the other hand, you charge a 24V battery bank with a 12V panel, all of the panel’s potential will be wasted as the voltage of the panel must be higher than the voltage of the battery bank.

The Maximum Power Point Tracking (MPPT) Solar Charge Controllers

MPPT controllers have a DC to DC converter inside. This enables them to take one voltage on the input and use that for charging a battery of, typically, varying voltage. For example most MPPT charge controllers require the voltage of the solar array be more than that of the battery bank, this allows for the single circuitry type that will drop voltage into what is needed. Designing it this way allows for one to string solar panels in series preventing as many wires running to the array. Typically MPPT controllers are more than 95% efficient.

Inside an MPPT charge controller is a small computer designed to apply load to the solar panel in a way that optimizes the amount of power pushed to the battery bank.

A major advantage of MPPT controllers is your flexibility in components on each side. When using PWM controllers, the solar array voltage has to be matched to the battery bank voltage which means purchasing a certain voltage of panel and typically running them all in parallel which could include many more wires. When you can choose a higher voltage panel, use smaller wires, and select a higher voltage battery bank, your system can become much more future proof from the beginning. The high-voltage systems produce less current, which means smaller conductors can be used. Also keep in mind that many solar components are sized based on current/amps, so as you increase voltage you increase capacity for the same amount of current.

Beene Brothers strives to keep this in stock for $100 as a convenience. If we don’t have it available, Amazon and Aliexpress should be able to set up you with a unit.

To Sum It Up

If you are planning to purchase a solar system, a solar charge controller is just as important as an inverter or solar panels. Thankfully there are options such as the one listed in the sidebar here which support a range of input and battery voltages. One way to cut costs is to utilize low-cost, high-voltage systems coupled with an MPPT controller.


Simple Off Grid Solar Wiring

Perhaps you’d like to build your own setup that includes Solar Panels, Batteries for storage, and an Invert for AC appliances. It’s good to understand how all the pieces wire together and where the power flows for choosing wire sizes and fuses. I have put together a diagram showing a simple method of wiring using the Charge Controller as the bus bar. When your amperage gets high enough you’d run an external bus bar to support larger wire. But this setup works up to the 40 amp range which the 10 gauge wire I’m using here supports. Keep in mind you should over-rate residential wiring. In my case if I have wire rated at 40 amps for my 12″ run and my inverter can pull 31 then 31 * 1.25 = 39 so I am within the 40A limit.

I am going to start at the battery as every charge controller I’ve seen requires the battery be connected before the Solar Panels. In this example we have a 48 Volt Lithium Ion battery, which by the way is only just a little more expensive than running new lead acid batteries. Check out one of the videos on this page to see an example of putting one together.

This battery has a BMS built in which provides our overcurrent protection known commonly as a fuse. We run the positive and negative wires from the battery straight to our charge controller where it should be clearly marked. This charge controller has two terminals for each polarity which is handy for our use case. No fuses are needed on this connection.

Wiring Diag.

Second step will be our Inverter. Our Inverter has fuses built in. It is certainly an option to run an external fuse so that if it blows it would be less trouble to replace, but for the sake of simplicity we will wire the Inverter straight to the remaining battery terminals of the Charge Controller. At this point the Charge controller should be on and you can go through the manual, or if you are using a Lithium Ion battery and the MrPowr charge controller check out the video on this page for a quick run-down, and make sure the settings are correct for the voltage and charge profile of your battery. This way when we connect the solar panels in the next step you know it’s ready to start charging with the power of the sun!

Time to free the electrons! Our final step is connecting some some Solar Panels to re-charge that battery you’re definitely not already running an air-conditioner off of. Yes I know it’s hot in that hunting cabin, may as well get the cool air blowing before you go outside to wire up the panels.

These panels are wired in series, each + of a panel is connected to the – of the next. Each end of the series will then have a + or a – that runs back to the charge controller. This should be clearly marked on the Charge Controller. This is another section where you will want a fuse or breaker in-line. Easiest is to get one of these nifty mc-4 connectors that has a fuse built in. You will need to determine what amperage of fuse you need though from the get-go to make sure you are protected and also don’t blow the fuse immediately after connecting. Since all of these panels are in series and a single panel is rated at 10 Amps max I chose a 15 Amp fuse since it was the next step up. The biggest consideration is you don’t want a fuse that has a higher rating than your wire can manage.

A massive part in staying safe is understanding what’s going on and not just plugging in where someone on the internet is telling you to. Here are some great resources on understanding the size of wire to use and what fuse size to use.

 

Renogy’s site for calculating wire sizes

Renogy’s site for calculating fuse ratings

Check out this video on how I repurposed the battery out of a BMW Electric Vehicle.


Video on setting up charge profile for Lithium Ion batteries.


Small Off-Grid

400 Watt Off-Grid Solar Setup

I see this as a starter system that can charge phones, laptops, run your television, etc. while leaving room to add a Lithium 12 volt battery and some extra solar panels to increase the capacity later on. The main disadvantage.

With one of my panels you’d have 400 Watts of power coming in while the sun is up high. In an optimal position this would be about 2.4kw for the day. Enough that you could run a small air conditioner while the sun is shining, especially if your standard 100AH lead acid battery can only hold 1.2Kw of that energy.


 Advantages

  • No batteries to balance when only 1 is in place
  • No BMS or complicated Lithium Ion to worry about
  • More of a known quantity
  • Could use a battery that is already in place in your setup
  • Inexpensive
  • Expandable later

Disadvantages

  • Inverter is 12 volt, so you can’t move to 24 or 48 volts without buying a new one
  • If you expand the system very far you’ll be dealing with lots of amps, therefore large wire sizes
  • Lead Acid batteries aren’t known for their longevity, expect 300-500 cycles from a new battery


Beene Brothers strives to keep this in stock for $100 as a convenience. If we don’t have it available, Amazon and Aliexpress should be able to set up you with a unit.


Small-Tier Off-Grid

400 Watt Off-Grid Solar Setup

I see this as a starter system that can charge phones, laptops, run your television, etc. while leaving room to add a Lithium 12 volt battery and some extra solar panels to increase the capacity later on. The main disadvantage.

With one of my panels you’d have 400 Watts of power coming in while the sun is up high. In an optimal position this would be about 2.4kw for the day. Enough that you could run a small air conditioner while the sun is shining, especially if your standard 100AH lead acid battery can only hold 1.2Kw of that energy.


 Advantages

  • No batteries to balance when only 1 is in place
  • No BMS or complicated Lithium Ion to worry about
  • More of a known quantity
  • Could use a battery that is already in place in your setup
  • Inexpensive
  • Expandable later

Disadvantages

  • Inverter is 12 volt, so you can’t move to 24 or 48 volts without buying a new one
  • If you expand the system very far you’ll be dealing with lots of amps, therefore large wire sizes
  • Lead Acid batteries aren’t known for their longevity, expect 300-500 cycles from a new battery


Parts

Beene Brothers strives to keep this in stock for $100 as a convenience. If we don’t have it available, Amazon and Aliexpress should be able to set up you with a unit.

Shoot me a text or call me, Christopher, at (682) 730-0725 to see what we might have in stock for solar panels.


Mid-Tier Off-Grid

1200 Watt Off-Grid Solar Setup

With 1.2Kw of Solar and a 3.8KWh battery this setup with the right sun exposure can run a 5000 BTU air conditioner for 6 hours while the sun shines and another 7 hours after dark. The Inverter listed below could even start the 8000 BTU air conditioner I tested it with, it’s a beefy unit.


Advantages

  • Large enough battery to run small air conditioner for 7 hours
  • Lithium batteries that should last 3000 cycles or more
  • 48 Volt system that requires much smaller wires to handle the wattage
  • Still room for more solar panels or bigger inverter

Disadvantages

  • Inverter is 1500 watts, could be undersized for running two AC’s or cooking equipment
  • Costs considerably more than the 12 volt system