Thinking about getting Batteries for your Solar PV system or a battery backup system? Sundriven can help. There are a range of types of batteries for these uses, including lithium ion and lead acid batteries.

A lithium ion battery is a lithium based battery such as a lithium iron phosphate, lithium cobalt oxide or lithium manganese oxide battery. There are differences between each type of lithium ion battery, however in most cases characteristics of each type include:

• a life span of 5 to 10 years for lithium iron phosphate, 5 to 7 years for lithium cobalt oxide, 10 to 30 years for lithium manganese oxide
• greater power storage and release than lead acid batteries of a similar size and weight
• faster charging times than lead acid batteries, flow batteries, salt water batteries
• round trip efficiency of 89% for lithium iron phosphate, 97% for lithium cobalt oxide, 75% to 95% for lithium manganese oxide
• susceptible to fire risk and therefore requires careful safety management
• depth of discharge 50% to 90% for lithium iron phosphate, 50% for lithium cobalt oxide, 90% for lithium manganese oxide
• cycle life (i.e. number of charge-discharge cycles) 3,000 to 6,000 cycles for lithium iron phosphate, 800 to 1,200 cycles for lithium cobalt oxide, 5,000 to 10,000 cycles for lithium manganese oxide

A deep-cycle battery is a lead-acid battery designed to be regularly deeply discharged using most of its capacity. In contrast, starter batteries (e.g. most automotive batteries) are designed to deliver short, high-current bursts for cranking the engine, thus frequently discharging only a small part of their capacity. While a deep-cycle battery can be used as a starting battery, the lower “cranking amps” imply that an oversized battery may be required.

A deep-cycle battery is designed to discharge between 50% and 80% of its capacity, depending on the manufacturer and the construction of the battery. Although these solar batteries can be cycled down to a 20% charge, the best lifespan vs cost method is to keep the average cycle at about a maximum 50% discharge. There is a direct correlation between the depth of discharge of the battery, and the number of charge and discharge cycles it can perform.

Deep cycle solar batteries are often used in off-grid solar and wind power applications. Unlike a car battery, they are designed to be discharged to a greater depth and more often. The most common type of battery for deep cycle applications are AGM (Absorbed Glass Mat), Gel and Flooded.

Deep-cycle lead acid batteries tend to have the characterics of:

• a life span of 3 to 15 years (depending on how they are used)
• cheaper than other batteries
• about 80% of components are recyclable
• safe and reliable, with well-established safety standards
• battery compartment or room requires very good ventilation to prevent gas build-up
• depth of discharge 50%
• cycle life (i.e. number of charge-discharge cycles) 2,000 to 3,000 cycles

At Sundriven, we are experts in flooded, AGM and Gel deep cycle battery technologies. If you need a helping hand in battery selection, contact our friendly team and they’ll be glad to assist you!

Did you know you might be also eligible for a renewable energy rebate if you buy a deep cycle battery as part of a full system? Ask our team for further details.