Deep cycle battery: RC vs Ahr??

johnm1 wrote:
I understand that I don't want CCA since I have no starting load but this stuff makes my head swim.

BTW: Trojan lists both RC and AH for the T105
http://www.trojanbattery.com/product/t-105/

Nothing wrong with a manufacturer listing both but like said, the 20 hour rate is normally used for comparing batteries for deep cycle use.

I understand that I don't want CCA since I have no starting load but this stuff makes my head swim.

BTW: Trojan lists both RC and AH for the T105
http://www.trojanbattery.com/product/t-105/

Reserve capacity is number of minutes battery can supply 25 A. Amp Hours is the Amperage a battery can supply over its rated time (usually 20 hours). Batteries designed for deep cycle use are usually rated in AH, batteries rated for vehicle/dual use are usually rated in RC.

A battery rated 120 min RC would be providing 50 AH; but that would be at the 2 hour rate which is a pretty high draw. This battery would be able to provide more AH total at a lower draw.

A battery rated 200 AH (at the 20 hour rating) would be able to supply 10 Amps for 20 hours. This battery would probably be able to provide about 300 AH at a 100 hour rating.

I think batteries rated in AH are designed for true deep cycle use; batteries that have a starting Amperage rating and an RC rating are designed for dual use, and are not truly suited for deep cycle use.

Doug

ReadThe 12 Volt Side of Life, maybe it will help.

Standard for deep cycle batteries is AH at 20 hr rate. Reserve Capacity is a measurement for starting and marine hybrid batteries.

If choosing a battery that has both ratings, select by weight. More lead = more goodness.