This is what I think we need to take away from this discussion:
afreegreek wrote:The most practical number to use is 50% DOD on a regular basis. This does NOT mean you cannot go to 80% once in a while. It's just that when designing a system when you have some idea of the loads, you should figure on an average DOD of around 50% for the best storage vs cost factor.
While an occasional dip down to 80% DOD may be acceptable there are some important things to remember about discharging to 80%:
- You'll want a meter to track your amp-hr usage as discharges below 80% will damage the battery.
- The deeper you discharge it, the more important it is to recharge it promptly to avoid permanent loss of capacity.
Discharging to 80% is taking a battery right to the ragged edge of its performance capability. I don't like to stress any of my systems that way as I don't want a failure when I'm out in the middle of nowhere. I also don't like to replace batteries more often than I have to as they don't ever seem to get any cheaper. Yes, you can take a battery down to 80% DOD routinely but you do do so at a greater risk of battery failure IMHO.
Bruce