Re: [RE-wrenches] Depth of discharge

2011-03-26 Thread Kent Osterberg
Wrenches, I noticed an error in my reply below when Allan's second comments arrived. Correction: the battery is considered 100% discharged (not 80%) at 10.5 volts (1.75 vpc) under the conditions of use. Kent Kent Osterberg wrote: William, I'll try to add a little to Allan's and

Re: [RE-wrenches] Depth of discharge

2011-03-26 Thread Allan Sindelar
Kent and list, And I was half awake this morning and realized my error in yesterday's post to which you responded... I said "A battery is considered empty at 10.75V (12V), or 1.79 VPC." No, it's at 10.5V, or 1.75 VPC, as you have correctly stated. Sorry. Allan

Re: [RE-wrenches] Depth of discharge

2011-03-26 Thread James Surrette
Evening all, A quick note on DOD. Batteries / cells are often rated at voltages above and below 1.75VPC (1.7 - 1.85 are common), so ratings should be verified with the supplier / model. However, as anyone that has ever run a discharge test knows, the time / available AH from 1.8 to 1.7VPC

Re: [RE-wrenches] Depth of discharge

2011-03-25 Thread William Miller
Allan: Is it possible to discharge a battery to 80%. What is the battery voltage one would expect with that DOD? William At 02:28 PM 3/25/2011, you wrote: William, I use 80%, as the intent is that this is maximum, not typical. It's directly used to calculate the battery capacity on the

Re: [RE-wrenches] Depth of discharge

2011-03-25 Thread Allan Sindelar
William, Here I am repeating the RE equivalent of GAAP, Generally Accepted Accounting Principles, as applied to battery sizing... A battery is considered empty at 10.75V (12V), or 1.79 VPC. When you test a battery's capacity, it's generally down to this point. How

Re: [RE-wrenches] Depth of discharge

2011-03-25 Thread Kent Osterberg
William, I'll try to add a little to Allan's and Ronald Parades' comments. Nearly every battery manufacturer specifies a maximum 80% depth of discharge (DOD); that corresponds to about 10.5 volts for a nominal 12-volt battery. Notice how close that is to the default setting used by many