Frequently Asked Questions

The Flexcharge Energy State Taper Charge Process monitors the battery for the full charged resting voltage of the batteries cells. There are tremendous advantages to this charge method.

•Zero overcharging

•Less need for temperature compensation

•Exceptionally low gassing (Up to 90% less)

•Non-Destructive Micro-Equalization at each full charge

•The battery’s chemical processes actually control the charging

•No RFI or EMI emissions to interfere with radio equipment

The Flexcharge method greatly reduces the need for temperature compensation. This occurs because the plate voltage is not constantly held at the critical plate saturation point. Tapering is controlled by the battery’s level of charge rather than with timers, or fixed voltages as in PWM and other constant voltage charge methods. The battery takes exactly what it needs rather than being forced to take a set voltage. With the Flexcharge method you can charge your battery bank indefinitely and overcharging will not occur.    The batteries will last longer,require less watering maintenance, and hold a better charge. As charging begins the controller allows full charging current to pass directly to the battery. When the battery voltage rises slightly above the plate saturation point, the controller opens the charging circuit. Much like a sponge will continue to absorb water towards its center after it has taken it all into its surface, the chemical charging process continues after the charging current has been removed.  As the charge is absorbed the battery’s voltage will fall. When the battery voltage has floated down to approximately 13.5V to 13.8V on a 12 V system,   it is ready to accept another charge pulse. This charge regulation method is actually controlled by the battery’s ability to accept and absorb energy. When the battery needs more energy indicated by plate voltage, the controller applies it. Mid way in the charging cycle the controller will cycle ON and then OFF sending full charge current pulses into the plates. A process which charges with very low gassing, and equalizes the plates with each cycle.  As the battery reaches a higher level of charge the amount of time the controller spends in charge is reduced, and the time in rest is increased. At full charge the controller will apply short duration pulses to maintain the battery at an average voltage of about 13.5 volts. This keeps gassing to a minimum while effectively trickle charging, and equalizing at the same time.

There has been a lot of discussion over which charge process is better, PWM, or this method.  To add fuel to the fire, each company making “ON-OFF”controllers has chosen different voltages to set the disconnect and reconnect points.  We have seen controllers using a version of this method where the reconnect voltage on a 12V system was set at 12.6V @70°F.  On this system the batteries would never see more than 80% charge, and likely much less. The PWM type controllers will obviously regulate the charging of your batteries, and with proper temperature compensation, heat sinks, and the correct Bulk-Regulate-Float (3 stage) algorithm will do a pretty good job but at less efficiency, but why settle when you can get so much more in a charge regulator.  Instead of the three stages with PWM you get an infinitely variable charge process which will supply the battery with exactly what it needs and only when it needs it.  You get less plate saturation gassing, non destructive equalization and Zero EMI/ RFI

Diodes are like an electronic check valve and when used on a solar panel, will prevent back flow of power from the battery as well as prevent multiple panels from interacting with each other in a system. When a solar panel is shaded or is not performing as well as the panels next to it, the power from the good panels will try to bring up the voltage of the lower panel instead of sending the power to the battery. With a blocking diode on each panel the power from each panel goes to the battery independently of what the other panels are doing. This is very important where you may get shadows on one panel such as from the rigging on a sailboat, tree shadows or where solar panels are not all aimed the same direction. All systems should have blocking diodes on each panel no matter what brand of charge controller is being used. The diodes that are found in a new panel are most always “by pass” diodes and do not serve the same function as a blocking diode. You will still need a blocking diode on the panel. The Flexcharge™ NC series of controllers are designed without internal isolation so when adding blocking diodes you are not causing the increased power loss of dual isolation.

We show a blocking diode on wind systems. If your system is generator based it must have a blocking diode. If your system is alternator based and has a rectifier, the rectifier is diode based and no additional diode needs to be added.

The Flexcharge™ Programmable Timer includes a small battery to maintain the programming memory. If the timer is installed with constant 12 volt power on the timer, the memory battery will last at least 3 years. To change the CR2032 battery you need to remove the black back cover from the timer. Do this by inserting a knife blade between the gray box edge and the black cover. The cover is only glued at the corners and will pop off as you move the knife toward a corner. Once the cover is off the battery compartment will be visible. Remove the old battery and install the new one with the + side of the battery toward the outside of the box. The black cover is cosmetic only and it is your choice if you want to re-glue it back in place.

On any generator or alternator based system it is important to use a controller that has the Divert feature. A Divert Load can be any resistance load that is equal to the maximum output of the generator or alternator. Load resistors or heating elements are ideal. A DC motor will work but in many cases finding a motor that draws enough amperage is difficult. Do Not use appliance type loads such as inverters, refrigerators, or other similar devices because they usually don’t start instantly and also usually need regulated power. Divert power is raw power directly from the generator or alternator. The purpose of the divert load is to keep the rpm of the generator or alternator within safe limits and to keep the voltage from going open circuit that will eventually cause a failure. We offer a couple of choices of divert loads. Divert Load They can be used together in multiples to create a larger Divert Load if needed.

Make sure you do not have any wire to wire crimp connections in your system. Solder all wire to wire connections as well as any ring terminals on the ends of wires. If you feel a connection point that is warm or hot, it is bad and is wasting power. Fix it. Fuse holders are often a poor connection point depending on how the fuse is connected and if the wires in the fuse holder are only crimped. A fuse holder using the glass tube fuse and that only has a spring loaded button on each end of the fuse is bound to fail. We have seen them get so hot that they melt the fuse holder case. For that style fuse, use a holder that has a ring around each end of the fuse for a secure connection.Be sure you have blocking diodes on the solar panels.

Too small a wire will waste power as heat. Even small amounts of loss that you can’t feel will make a big difference over time. If you tell us the distance between the solar panels and the controller, along with the maximum amperage, and the system battery voltage, we can help you with the recommended wire size. All rating are based on stranded copper wire.

Distance in feet between the solar panels and the charge controller at the battery area ___

Total expected maximum amperage of the charging source ___

System battery voltage (12, 24, 36, 48) ___

For a 12 volt battery system the peak power voltage of the solar panels needs to be around 15 volts. For a 24 volt battery system the peak power voltage of the solar panels needs to be around 30 volts. If you wire your panels for a higher peak power voltage (in series) than you system requires, you will reduce the amperage and essentially cut you power in half or worse. This is only true of solar systems and does not apply to generator or alternator systems such as wind or hydro systems.

You can wire your panels in series for a higher peak power voltage and use an MPPT controller to bring the peak power voltage back down to the proper voltage but then you are using a lot of electronics to accomplish that and the result is a less efficient system then if you just use the panels at the proper voltage with a Flexcharge controller. Look at any MPPT controller with a 20 amp or larger capacity and note it is in a metal case usually with heat fins and often with a cooling fan. This is all to get rid of the heat generated by the electronics and the heat is energy that never made it to the battery. Flexcharge controllers run cool demonstrating that there is little to no loss in the controller. We do not offer MPPT controllers. The original design goal of all Flexcharge™ controller, was and is, to be the most efficient in the world and MPPT technology does not fit that goal.

The patented algorithm of the Flexcharge control process is not PWM, MPPT or 3 stage. “Our Energy State Taper Charge” method is an infinite stage process with each stage fully controlled by the battery needs. See our charge process explained on the page Charging Algorithm Explained.

Lead acid batteries have been used as a popular storage tool for solar energy for many years. Despite the emergence of newer battery technologies like lithium-ion, lead-acid batteries still hold an important place in the renewable energy industry.

One significant advantage of lead acid batteries is their relatively low cost compared to lithium-ion batteries. Lead acid batteries are widely available and have been produced for over 150 years, making them a tried and tested technology. They are also widely recyclable, with over 99% of the lead used in batteries being recovered and recycled into new batteries.

Furthermore, lead acid batteries are more tolerant of a wider range of temperatures and can withstand overcharging, making them a more robust option for energy storage. They are also suitable for stationary applications where weight is not an issue, making them a popular choice for home solar power systems.

One of the most significant benefits of using lead acid batteries for solar energy storage is their low environmental impact compared to lithium-ion batteries. The production of lithium-ion batteries requires rare earth elements, such as cobalt and nickel, which are in short supply and often sourced from environmentally damaging mines. By contrast, lead is a widely available material that can be sourced sustainably and recycled efficiently.

In conclusion, lead acid batteries remain a reliable and cost-effective option for storing solar energy. While lithium-ion batteries may offer higher energy density and longer lifespans, they require rare earth elements that are in short supply and may have a greater environmental impact. Lead acid batteries offer a sustainable and robust solution for solar energy storage that is well-suited to stationary applications, making them an ideal choice for homeowners and businesses looking to invest in renewable energy.

Lithium-ion batteries have become increasingly popular in recent years as a storage tool for solar energy due to their high energy density and long lifespan. However, there are also risks and environmental costs associated with the use of lithium-ion batteries for solar energy storage.

One significant risk of lithium-ion batteries is the potential for thermal runaway, a phenomenon in which a battery undergoes an uncontrollable increase in temperature and releases energy rapidly. This can lead to fires or explosions, as seen in high-profile incidents such as the Samsung Galaxy Note 7 recall. While the risk of thermal runaway is relatively low in well-designed and maintained battery systems, it remains a concern for users and installers of lithium-ion batteries.

Furthermore, the production of lithium-ion batteries requires rare earth elements such as cobalt and nickel. These elements are often sourced from environmentally damaging mines, which can cause soil and water pollution and harm local ecosystems. In addition, the mining process can be hazardous to workers and local communities.

Another environmental cost associated with lithium-ion batteries is their disposal. While they have a longer lifespan than many other battery types, lithium-ion batteries still eventually reach the end of their usable life and must be disposed of or recycled. Improper disposal of these batteries can lead to toxic chemicals leaking into the environment and harming wildlife and human health.

Finally, the transportation of lithium-ion batteries can also pose environmental risks. They are typically transported over long distances, often by plane or ship, which can contribute to greenhouse gas emissions and other environmental impacts.

In conclusion, while lithium-ion batteries offer many benefits as a storage tool for solar energy, there are also risks and environmental costs associated with their use. These include the potential for thermal runaway, the environmental impact of mining rare earth elements, the disposal of used batteries, and the transportation of batteries. As the use of lithium-ion batteries for solar energy storage continues to grow, it will be important to address these concerns and develop sustainable and responsible practices for their production, use, and disposal.