AGM battery
Anybody have experience with AGM battery in your RV? In particular the Optima yellow or blue top. Or I guess any other type of AGM battery. Any reason not to use them? Thanks, Dave
Forum Discussion
Hi Coach,
Don't confuse voltage drop with capacity.
Look at the number of amp-hours at the 20 hour rate. Optima is a great battery but has by its design less amp-hours per unit volume of space consummed. I.E. there is lots of empty space that could be filled with flat pasted plates.
Another good measurement for "house" battery banks is called "reserve capacity". Again Optima has less per unit volume of space occupied by the jar.
An Optima has 55 amp-hours. Reserve capacity 140 minutes.
A lifeline group 27 has 100 amp-hours, reserve capacity 189 minutes; the group 31 is 105, reserve capacity 195 minutes.
The group 27 is probably a similar overall "foot print" to the Optima.
If you compare the Optima with a flooded battery, voltage drop under heavy loads may be better (i.e. lower) because of the large surface area and low resistance of the Optima. Optima claims 350 cycles to flat dead. Other AGM makers don't recommend that sort of abuse, but have a similar cycle capacity. Of course, a flood battery can't tolerate being driven to flat dead more than a very small number of times.
If you compare The Optima with the lifeline, under heavy loads, it *might* have a slightly better voltage drop but not enough to level the playing field.
Don't confuse voltage drop with capacity.
Look at the number of amp-hours at the 20 hour rate. Optima is a great battery but has by its design less amp-hours per unit volume of space consummed. I.E. there is lots of empty space that could be filled with flat pasted plates.
Another good measurement for "house" battery banks is called "reserve capacity". Again Optima has less per unit volume of space occupied by the jar.
An Optima has 55 amp-hours. Reserve capacity 140 minutes.
A lifeline group 27 has 100 amp-hours, reserve capacity 189 minutes; the group 31 is 105, reserve capacity 195 minutes.
The group 27 is probably a similar overall "foot print" to the Optima.
If you compare the Optima with a flooded battery, voltage drop under heavy loads may be better (i.e. lower) because of the large surface area and low resistance of the Optima. Optima claims 350 cycles to flat dead. Other AGM makers don't recommend that sort of abuse, but have a similar cycle capacity. Of course, a flood battery can't tolerate being driven to flat dead more than a very small number of times.
If you compare The Optima with the lifeline, under heavy loads, it *might* have a slightly better voltage drop but not enough to level the playing field.
Coach-man wrote:
OK, I do not mean to steal the thread or sound like an idiot, BUT I am curious about the statement "Optima has the lowest capacity to foot print because of their spiral cells".. Everything I have ever heard about Optima's is that it is about the spiral design that gives them more power in the smaller foot print? I have purchased Optima's and by any measurement CCA's etc. they are smaller than a similar rated traditional battery, so I am confused as to where you got your information??
