Do AGM's charge quicker?
Looking to cut generator time. Have solar but sometimes have little to no sun when dry camping. Read AGM's charge up to 5X faster than flooded. How can that be, converter charger only puts out so mu...
Forum Discussion
Let's set the rules for an apples-to-apples spec sheet comparison - no messing around in the garage with batteries, wiring, chargers, or instruments required - and no real world trials using an actual RV out camping or in the yard required:
A. Take two 230 amp hour 6V AGM deep cycle (GC?) batteries connected in series to produce 230 amp hours of deep cycle 12V AGM capacity. That amounts to 6 stacked 2V cells in series with each other. Look at, say, a Lifeline spec sheet for the battery model in that combination and do a simple math internal resistance addition to get total internal resistance - what does the total internal resistance turn out to be for the resulting large 12V battery?
B. Now take two 115 amp hour 12V AGM deep cycle batteries connected in balanced parallel to produce 230 amp hours of deep cycle 12V AGM capacity. That amounts to 6 stacked 2V cells in series with each other in one 12V battery ... and that battery in parallel with the same configuration in the other 12V battery. Now look at, say, a Lifeline spec sheet for the battery model in that combination and do a simple math internal resistance parallel circuit calculation to get total internal resistance - what does the total internal resistance turn out to be for the resulting large 12V battery?
It's now pure electrical principles that cannot be violated: Which battery combination - two 6 volters or two 12 volters - of similar construction from the same manufacturer has the lowest total internal resistance - A. or B.?
For any given battery starting state of charge and ambient temperature and equipment cabling size and battery charger... the battery combination with the lowest internal resistance will absorb more current at any particular charging voltage from any particular charger that is capable of supplying the respective currents.
The same armchair spec sheet comparisons can indicate whether 6V/12V liquid deep cycle battery combinations will charge faster than equivalent 6V/12V AGM deep cycle battery combinations.
A. Take two 230 amp hour 6V AGM deep cycle (GC?) batteries connected in series to produce 230 amp hours of deep cycle 12V AGM capacity. That amounts to 6 stacked 2V cells in series with each other. Look at, say, a Lifeline spec sheet for the battery model in that combination and do a simple math internal resistance addition to get total internal resistance - what does the total internal resistance turn out to be for the resulting large 12V battery?
B. Now take two 115 amp hour 12V AGM deep cycle batteries connected in balanced parallel to produce 230 amp hours of deep cycle 12V AGM capacity. That amounts to 6 stacked 2V cells in series with each other in one 12V battery ... and that battery in parallel with the same configuration in the other 12V battery. Now look at, say, a Lifeline spec sheet for the battery model in that combination and do a simple math internal resistance parallel circuit calculation to get total internal resistance - what does the total internal resistance turn out to be for the resulting large 12V battery?
It's now pure electrical principles that cannot be violated: Which battery combination - two 6 volters or two 12 volters - of similar construction from the same manufacturer has the lowest total internal resistance - A. or B.?
For any given battery starting state of charge and ambient temperature and equipment cabling size and battery charger... the battery combination with the lowest internal resistance will absorb more current at any particular charging voltage from any particular charger that is capable of supplying the respective currents.
The same armchair spec sheet comparisons can indicate whether 6V/12V liquid deep cycle battery combinations will charge faster than equivalent 6V/12V AGM deep cycle battery combinations.
