Thor Forums

[Beau388]

[QUOTE=blw2;156489]re. that 50% rule of thumb....


from Trojan's user guide...
"Do not discharge your battery to more than 80% depth of discharge. This safety factor will eliminate the chance of over-discharging and damaging your battery"
(means that you should be able to take it down to 20% of the capacity (100-80=20) QUOTE]


The quote is correct but your inference is not. Discharging any lead acid battery beyond 50% of it rated capacity, VLRA, AGM, GEL or flooded, will shorten it life span. Drawing the battery down to below 20% of its rated capacity tends to kill it outright, just like letting the water level get below top of the plates kills a battery. How much will that extra 30% of discharge shorten battery life is debatable among battery manufactures, but it is significant (up to 1/3 in some batteries). After all; all lead/acid batteries use the same chemistry. Alloying the plates with antimony, selenium or calcium doesn't change the chemistry. The paste used is inert and only acts for a seed for the lead sulfate crystals and leads to a higher potential discharge rate without stratification.