What makes a good battery and inverter combination?
First let's look at the different types of batteries commonly used with inverters.
The most common are deep cycle batteries sold at big box stores. These batteries commonly are of the lead acid type and are designed to dispense power at a steady rate almost completely (45% to 75% in most cases). While these batteries can be cycled down to 20% charge, the best lifespan versus cost analysis reveals that it is to keep the average cycle at about 45% discharge. When discharging these batteries we need to look at how much we discharge the battery and the correlation and how many charge/discharge cycles you can expect to be able to perform. It is best practice to consult with your battery manufacture for that information.
The structural difference between deep-cycle batteries and starting batteries found in motor vehicle applications is in the types of lead battery plates that are used. Deep cycle battery plates have thicker active plates, with higher-density active paste material and thicker separators. The alloys used for the plates in a deep cycle battery may contain more antimony than that of starting batteries that are designed for quick bursts of energy for short periods. One of the noticeable benefits of thicker plates is throughout the life cycle of charge/discharge incidence of corrosion can be significantly reduced.
Traditional lead acid deep cycle batteries can be found in two types, Flooded Lead Acid and Valve Regulated Lead Acid. The Flooded Lead Acid (FLA) type is what we commonly see as the "default" deep cycle battery. Deep cycle do however come in other varieties other than the traditional lead acid. In addition to the FLA type you can find deep cycle in the Valve Regulated Lead Acid (VRLA) type.
Traditional Lead Acid Batteries do require vigilant maintenance routines for battery longevity. Contact the manufacturer for the recommended process.
The VRLA type has two separate type within it as well. The Gel style and the Absorbed Glass Mat (AGM) style. while both are very good options the AGM style tends to be a little more rugged. The AGM style has a reinforcement of absorbed glass mat separators that helps to reduce damage caused by severe damaging vibrations. Vibration can be detrimental to battery life due to potential for battery mount displacement or failure or battery case fracturing.
There are a myriad of manufacturers that make great batteries. Trojan, Lifeline, Duracell, Surrette, Deka, Dyno, and Exide to name a few.
So how does the inverter interact with the battery?
Simply put a power inverter, or inverter, is an electronic device built with circuitry that changes direct current (DC) that typically comes from solar, wind, or even automotive power to alternating current (AC) commonly found in homes.
The inverter does not produce any power; the power is provided by the DC source(s) listed above. These inverters do not use moving parts in the conversion process simply relying on circuitry to make the change.
A typical power inverter requires a relatively stable DC power source that is capable of supplying enough current for the intended power demands of the system. The input voltage depends on the design and purpose of the inverter.
Most commonly you can find smaller consumer as well as commercial 12 volt DC inverters that receive power from a rechargeable 12 V lead acid battery or from the vehicle electrical system.
Inverters can also purchased wired for 24 and 48 V DC voltages are common standards for home energy systems and some mobile/RV systems. Wind power and photovoltaic solar panels commonly supply 200 to 400 volts DC depending upon the manufacturer.
Once the buyer determines what voltage, wattage and amperage requirements they require an inverter will be purchase that will support the load.
So what kind of inverter do I buy?
It is important to determine what devices will be providing the load to the inverter. An inverter can produce a square wave, modified sine wave, pulsed sine wave, pulse width modulated wave (PWM) or sine wave depending on circuit design. The two most common waveform types of inverters are Modified sine wave and Pure sine wave.
Pure Sine Wave can be visualized as "ocean waves". Pure Sine Wave will relay DC to AC power in a more smooth and gentle manner causing little if any power disruption. It is generally considered a best practice to utilize Pure Sine Wave for most sensitive electronics such as computers, printers, medical devices, cellular phones. While these "may" work with Modified Sine Wave, damage may occur.
Modified Sine Wave can be visualized as "stair steps". Modified Sine Wave is not nearly as smooth and gentle as Pure Sine Wave and as a result can cause damage to sensitive electronics. Generally speaking, power tools with cords, refrigerators, A/C units, etc are better suited for Modified Sine Wave.
It should be noted that newer battery driven power tools such as the Dewalt Flex Volt series and the Milwaukee Fuel series both recommend Pure Sine Wave for their batteries and battery chargers. It is a best practice to find out from your tool manufacturer what they recommend for rechargeable tools.
Can I use more than one inverter such as one Modified Sine Wave and one Pure Sine Wave?
Absolutely! While not a common practice it is not entirely unheard of. A best practice would be to have the positive terminal from the DC source to EACH inverter be supplied with a fuse. In a vehicle application with free and available space this can be an issue however.
What is the difference between High Frequency and Low Frequency?
Low frequency power inverters got the name because they use high speed power transistors in the inversion process from DC to AC. They do still drive the transistors at the same frequency (60 Hz or 50Hz) as the AC sine wave output. High frequency power inverters however, typically drive the transistors at a higher frequency closer to 50 KHz or higher.
While delivering the same amount of power, the low frequency inverter transformer outputs more power at each cycle, and in doing so it works harder, resulting in larger and heavier transformer and form factor.
A high frequency inverter on the inverse delivers less power at each cycle which allows the inverter to use a smaller and lighter transformer resulting in a smaller form factor. The compact design however, comes with a price, since it has a smaller transformer, most high frequency inverters will typically surge at a lower rate, and/or for much shorter periods of time than its low frequency cousins.
What else should I consider?
Cabling as well as fuses are very important. Manufacturers will have requirements in the user guides they produce. I plan on doing a post in the coming days about cabling and fusing.
First let's look at the different types of batteries commonly used with inverters.
The most common are deep cycle batteries sold at big box stores. These batteries commonly are of the lead acid type and are designed to dispense power at a steady rate almost completely (45% to 75% in most cases). While these batteries can be cycled down to 20% charge, the best lifespan versus cost analysis reveals that it is to keep the average cycle at about 45% discharge. When discharging these batteries we need to look at how much we discharge the battery and the correlation and how many charge/discharge cycles you can expect to be able to perform. It is best practice to consult with your battery manufacture for that information.
The structural difference between deep-cycle batteries and starting batteries found in motor vehicle applications is in the types of lead battery plates that are used. Deep cycle battery plates have thicker active plates, with higher-density active paste material and thicker separators. The alloys used for the plates in a deep cycle battery may contain more antimony than that of starting batteries that are designed for quick bursts of energy for short periods. One of the noticeable benefits of thicker plates is throughout the life cycle of charge/discharge incidence of corrosion can be significantly reduced.
Traditional lead acid deep cycle batteries can be found in two types, Flooded Lead Acid and Valve Regulated Lead Acid. The Flooded Lead Acid (FLA) type is what we commonly see as the "default" deep cycle battery. Deep cycle do however come in other varieties other than the traditional lead acid. In addition to the FLA type you can find deep cycle in the Valve Regulated Lead Acid (VRLA) type.
Traditional Lead Acid Batteries do require vigilant maintenance routines for battery longevity. Contact the manufacturer for the recommended process.
The VRLA type has two separate type within it as well. The Gel style and the Absorbed Glass Mat (AGM) style. while both are very good options the AGM style tends to be a little more rugged. The AGM style has a reinforcement of absorbed glass mat separators that helps to reduce damage caused by severe damaging vibrations. Vibration can be detrimental to battery life due to potential for battery mount displacement or failure or battery case fracturing.
There are a myriad of manufacturers that make great batteries. Trojan, Lifeline, Duracell, Surrette, Deka, Dyno, and Exide to name a few.
So how does the inverter interact with the battery?
Simply put a power inverter, or inverter, is an electronic device built with circuitry that changes direct current (DC) that typically comes from solar, wind, or even automotive power to alternating current (AC) commonly found in homes.
The inverter does not produce any power; the power is provided by the DC source(s) listed above. These inverters do not use moving parts in the conversion process simply relying on circuitry to make the change.
A typical power inverter requires a relatively stable DC power source that is capable of supplying enough current for the intended power demands of the system. The input voltage depends on the design and purpose of the inverter.
Most commonly you can find smaller consumer as well as commercial 12 volt DC inverters that receive power from a rechargeable 12 V lead acid battery or from the vehicle electrical system.
Inverters can also purchased wired for 24 and 48 V DC voltages are common standards for home energy systems and some mobile/RV systems. Wind power and photovoltaic solar panels commonly supply 200 to 400 volts DC depending upon the manufacturer.
Once the buyer determines what voltage, wattage and amperage requirements they require an inverter will be purchase that will support the load.
So what kind of inverter do I buy?
It is important to determine what devices will be providing the load to the inverter. An inverter can produce a square wave, modified sine wave, pulsed sine wave, pulse width modulated wave (PWM) or sine wave depending on circuit design. The two most common waveform types of inverters are Modified sine wave and Pure sine wave.
Pure Sine Wave can be visualized as "ocean waves". Pure Sine Wave will relay DC to AC power in a more smooth and gentle manner causing little if any power disruption. It is generally considered a best practice to utilize Pure Sine Wave for most sensitive electronics such as computers, printers, medical devices, cellular phones. While these "may" work with Modified Sine Wave, damage may occur.
Modified Sine Wave can be visualized as "stair steps". Modified Sine Wave is not nearly as smooth and gentle as Pure Sine Wave and as a result can cause damage to sensitive electronics. Generally speaking, power tools with cords, refrigerators, A/C units, etc are better suited for Modified Sine Wave.
It should be noted that newer battery driven power tools such as the Dewalt Flex Volt series and the Milwaukee Fuel series both recommend Pure Sine Wave for their batteries and battery chargers. It is a best practice to find out from your tool manufacturer what they recommend for rechargeable tools.
Can I use more than one inverter such as one Modified Sine Wave and one Pure Sine Wave?
Absolutely! While not a common practice it is not entirely unheard of. A best practice would be to have the positive terminal from the DC source to EACH inverter be supplied with a fuse. In a vehicle application with free and available space this can be an issue however.
What is the difference between High Frequency and Low Frequency?
Low frequency power inverters got the name because they use high speed power transistors in the inversion process from DC to AC. They do still drive the transistors at the same frequency (60 Hz or 50Hz) as the AC sine wave output. High frequency power inverters however, typically drive the transistors at a higher frequency closer to 50 KHz or higher.
While delivering the same amount of power, the low frequency inverter transformer outputs more power at each cycle, and in doing so it works harder, resulting in larger and heavier transformer and form factor.
A high frequency inverter on the inverse delivers less power at each cycle which allows the inverter to use a smaller and lighter transformer resulting in a smaller form factor. The compact design however, comes with a price, since it has a smaller transformer, most high frequency inverters will typically surge at a lower rate, and/or for much shorter periods of time than its low frequency cousins.
What else should I consider?
Cabling as well as fuses are very important. Manufacturers will have requirements in the user guides they produce. I plan on doing a post in the coming days about cabling and fusing.
