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.




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


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


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.

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.