These SMF batteries are again of two kinds - AGM(absorbed glass mat) and gel-cell . Both types are again VLRA ( valve regulated lead acid ) .. i.e they have a safety valve to release pressure in case of internal gas pressure buildup . Amaron's pro-biker range is a AGM + VLRA kind . These smf batteries have many advantages over our conventional batteries (flooded lead acid type) .
i) cannot spill acid
ii) can be mounted in any position ,like say vertically even ( since it does not spill )
iii) very low internal resistance allowing them to be charged and discharged rapidly & doesn't heat up at all during charging/discharging . Faster current discharge to reach the battery's terminals, i.e.. more cold cranking amperage for self starter motor .
iv) never requires addition of water - no maintenance or top-ups needed ever
.v) very high mechanical shock & vibration resistance .
vi) High power density, holding roughly 1.5x the AH capacity of flooded batteries per unit of weight .
vii) Depth of discharge for optimal performance is up to 80% while flooded batteries can only tolerate up to 50% discharge .
viii) VRLA+AGM batteries also have higher charge efficiency ; flooded cells convert 15-20% of the electrical energy into heat instead of potential power. Gel-cells lose 10-16% but AGMs as little as 4% .
ix) low self discharge ; While flooded cells lose up to 1% per day due to self-discharge, VRLAs lose 1-3% per month - i.e they can be stored for months without charging .
x) no acid fumes - the battery system is designed to be recombinant ( combines hydrogen and oxygen released during a overcharge back into water internally ) and eliminate the emission of gases .
Disadvantages :
i) Cost. AGM automobile batteries for example, are typically about twice the price of flooded-cell batteries in the same capacity - though this difference is rapidly reducing now .
ii) AGM batteries do not tolerate overcharging. Overcharging dissociates the water in the electrolyte, which is unable to be replaced (no provision for water/acid top up ), leading to premature failure. ( recombination efficiency is about 90% ) . Flooded batteries are the most forgiving and can stand a wider range of charging parameters. . Most battery service guys here use high current rapid chargers which boils the electrolyte ( you can see it if the refilling caps are open ) ... if you give your battery to such places for recharging ... you can say bye bye to your smf (agm) battery in one year
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and even if it gets discharged the distributor will charge it free of cost provided the battery should be in the warranty period & in case any issue arises the battery will be replaced free of cost!!!
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