The new type of sealed batteries contains "absorbed glass mats" or AGM between the plates. This is a very fine fiber borosilicate glass mat. These types of batteries have all the advantages of gel batteries, but can carry a larger load. There are also the so-called "starved electrolyte", as the mat is 95% saturated, not completely soaked. This means that the acid will not leak even if the battery is broken.
AGM batteries have some advantages over both gelled and flooded ones, costing about the same price as gelled batteries.
Since all the acid is contained in glass mats, it cannot spill even if the battery is broken. This means that it is not a hazardous material, and has a lower shipping cost. Moreover, since there is no liquid in the battery to freeze or expand, it is practically immune from freezing damage.
Almost all AGM batteries are "recombinant", which means that oxygen and hydrogen recombine inside the battery. They use the gas-phase transfer of oxygen to the negative plate to recombine them back into water during charging and prevent water loss through electrolysis. The recombining is normally 99 +% efficient, so almost no water is lost.
Charging voltages are the same as for all standard batteries, no special adjustments required, no problem with incompatible chargers. As the internal resistance is very low, the battery does not heat up even at very high charge and discharge currents.
AGM batteries have a very low discharge of 1% to 3% per month. This means that they can be stored for much longer without recharging than standard batteries. The Dream batteries can be almost fully recharged (95% or more) even after 30 days of full discharge.
AGM batteries do not have any liquid to spill, so even under severe overcharge conditions hydrogen emission is lower than its maximum value of 4% intended for aircraft and enclosed spaces. The plates of AGM batteries are tightly packed and securely mounted and can withstand shocks and vibration better than any other standard battery.
TPPL is an advanced form of lead-acid battery that has some advantages over AGM technology. First of all, TPPL batteries have the ability to charge quickly. Depending on the charging current and voltage, they can be fully recharged in 2.5 hours.
TPPL batteries have a lifespan of 15 years, while regular flooded batteries typically have a lifespan of 3 to 5 years. AGM batteries are known to last from 5 to 10 years. Although TPPL technology is not as compact as the lithium-ion technology, it can provide high energy concentration.
TPPL batteries have higher energy efficiency than the AGM technology. They can achieve a 43% reduction in energy by reducing floating power requirements. These batteries can perform at higher temperatures, which also reduces the air conditioning energy costs.