FAQ

Type of battery being used primarily depends on how often and the amount of time you will be running your system. In general, deep cycle marine/RV batteries and sealed batteries and are the best.

Correct wiring of your battery bank is important.  When your batteries are not wired correctly, your system may not work and/or permanent damage could occur.  So, always remember that series increases the voltage, and parallel increases the amps. Series is achieved by connecting positive of battery one to negative of battery two.  Parallel is achieved by connecting batteries positive to positive & negative to negative.

Cable sizing is determined by the size of your inverter.  National Electric Code standards are strongly suggested when wiring a system.  Recommended sizing is as follows; #4 gauge is not to exceed 157 amps DC (approximately 1500 watts), 1/0 is not to exceed 291 amps (approximately 3500 watts), and 4/0 is not to exceed 454 amps (approximately 5000 watts.)  These ratings are based on a 12 volt system

Keep the cables between your inverter and batteries as short as possible. This will help your batteries perform their best and keep the inverter's signal clean. The cables that come with the inverter are "rated" or good for up to six ft. If you plan for going over six ft., drop down to a larger gauge cable. Please call us if you are still unsure. This is pretty important stuff that should not be overlooked. If the cables between your battery and inverter get hot while under heavy load, then you should use heavier cables.

All deep cycle batteries are rated in amp-hours. An amp-hour is one amp for one hour, or 10 amps for 1/10 of an hour and so forth. It is amps x hours. If you have something that pulls 20 amps, and you use it for 20 minutes, then the amp-hours used would be 20 (amps) x 0.333 (hours), or 6.67 AH. The accepted AH rating time period for batteries used in solar electric and backup power systems (and for nearly all deep cycle batteries) is the "20 hour rate". This means that it is discharged down to 10.5 volts over a 20 hour period while the total actual amp-hours it supplies is measured. Sometimes ratings at the 6 hour rate and 100 hour rate are also given for comparison and for different applications. The 6-hour rate is often used for industrial batteries, as that is a typical daily duty cycle. Sometimes the 100 hour rate is given just to make the battery look better than it really is, but it is also useful for figuring battery capacity for long-term backup amp-hour requirements.

• Battery capacity (how many amp-hours it can hold) is reduced as temperature goes down, and increased as temperature goes up. The standard rating for batteries is at room temperature – 25°C (about 77°F).
• Battery charging voltage also changes with temperature. It will vary from about 2.74 volts per cell (16.4 volts) at -40°C to 2.3 volts per cell (13.8 volts) at 50°C.
• Even though battery capacity at high temperatures is higher, battery life is shortened. Battery capacity is reduced by 50% at -30°C (-22°F) but battery LIFE increases by about 60%. Battery life is reduced at higher temperatures for every 10°C over 25°C, battery life is cut in half. This holds true for ANY type of Lead-Acid battery, whether sealed, gelled, AGM, industrial or whatever. This is actually not as bad as it seems, as the battery will tend to average out the good and bad times.
• One last note on temperatures - in some places that have extremely cold or hot conditions, batteries may be sold locally that are NOT standard electrolyte (acid) strengths. The electrolyte may be stronger (for cold) or weaker (for very hot) climates. In such cases, the specific gravity and the voltages may vary.