Types of car batteries

How start stop systems relate to batteries

The start-stop system switches off a car's engine when the vehicle is stopped, for example while at a red light or in a traffic jam. This technology delivers between 5 and 10% lower emissions and a similar improvement in fuel economy. This increased starting demand often requires an AGM battery.

Vehicles with start-stop technology require AGM batteries. Fitting another type of battery impairs the fuel saving technology, and reduces the serviceable life of the battery. AGM batteries have increased durability, higher performance and a longer life. AA Battery Service is constantly expanding its range of AGM start-stop batteries to meet growing demand as more start-stop vehicles enter the market.

The benefits of AGM start-stop battery technology

• Three to four times more cycling life in order to meet the demands of start-stop vehicles.
• High charge acceptance which is critical for modern battery management systems.
• 100% leak-proof and spill-proof.
• Excellent starting power, so you can rely on the engine starting – even at a low state of charge.
• Totally maintenance-free.

About AGM car batteries

AGM (Absorbed Glass Mat) batteries are becoming more popular with modern vehicles as the demand for higher CCA (cold cranking amps) & RC (reserve charge) increases. AGM batteries are just like flooded lead acid batteries, except their electrolyte is absorbed and held in glass mats, as opposed to freely flooding the plates. There is no excess electrolyte in an AGM, so they are able to operate in any orientation (even upside down!), without ever having to worry about spillage.

All AGM batteries are VRLA (Valve Regulated Lead Acid) in design, and tend to run a slightly higher than atmospheric internal pressure. This pressure is controlled by an inbuilt valve regulator. When installed internally (in the boot or inside the cabin), a vent tube must be connected. Vent tubes must not be kinked in any way, and must vent outside the vehicle.

About calcium car batteries

Conventional low-maintenance batteries use grids of lead-antimony which is readily available, inexpensive, easy to cast, and used to produce rechargeable batteries that offer efficiency and low cost. In a calcium battery the antimony is totally substituted with calcium in all plates. This results in double the shelf life and virtually no gassing in the battery, resulting in less maintenance.

Calcium batteries do require a higher charge voltage (nominally 15 volts) to achieve the same level of charge as a normal antimony battery. They also require a periodic equalisation cycle to help maintain optimum operating condition. When installed in a vehicle designed for an antimony battery (i.e. a traditional 12 volt system which charges at 14 volts) the battery will only achieve 85% state of charge.

Advantages

• Higher cold cranking amps (CCA)
• Longer useful life
• Can be 100% maintenance free
• Will accept higher charge rates.

Disadvantages

• Takes longer recharge after being run flat
• Requires a calcium specific charger to restore to 100% state of charge

About deep cycle car batteries

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, and to be frequently discharged of only a very small part of their capacity.

Deep cycle batteries have much thicker plates than a regular automotive battery and are designed to be discharged down as much as 80% time after time. The major difference between a true deep cycle battery and others is that the plates are solid lead plates - not sponge. This gives less surface area and therefore less "instant" power which starting batteries need.

About spiral coil car batteries

A spiral coil battery is an AGM battery, but with a different construction. Like conventional AGMs, it is a high output battery, and is often found in high performance or off road vehicles that require extra torque for starting. Positive and negative plates are rolled together with a thin layer of absorbed glass mat in between providing more surface area and therefore produce higher current carrying capacity. These batteries are more resistant to excessive vibration, heat and higher charge rates. The spiral battery can have a shelf life up to 18 months without affecting starting ability.

About gel car batteries

Gelled batteries, or "gel cells" contain acid that has been "gelled" by the addition of silica gel, turning the acid into a solid mass that looks like hard jelly. The advantage of these batteries is that it is impossible to spill acid even if they are broken. The disadvantage is that they must be charged at a slower charge rate to prevent overheating. Excess heat will turn the “gel” into a liquid, damaging the cells. Gel batteries are often found in golf buggies, back up for house alarms and electric toys. There is a caution - gel cell batteries cannot be fast charged on a conventional automotive charger or they may be permanently damaged.