Comments 2
  1. — Jimmy Carter    Apr 14, 2007 14:21 PM    #

    I think that the person asking the question wanted to know what the voltage would be at 50% DOD and 80% DOD, in case they are using a volt meter….

  2. jerry Halstead    Apr 14, 2007 15:21 PM    #

    My understanding is that the voltage reading doesn’t give a reliable indicator of DOD%. Things to consider:

    * voltage sags under load, going up a steep hill the pack voltage could drop significantly

    * without a load the voltage of a lead acid battery will start to slowly rise (I’ve sat on the side of the road a few times waiting for a low battery pack to self-charge enough for the last block home…and it always worked)

    * chemistries and age: each battery type will have different characteristics, and capacities change as they get older

    With that said, after driving an EV for a while and watching the meters you can get a sense of how your pack is doing by watching the pack voltage under typical load.

    The battery university talks a bit about depth of discharge with different battery types.