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Best Battery Charger / Conditioner ?? Help wife is gonna kill me

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by SEaton, Dec 1, 2013.

  1. marcs_carhole

    marcs_carhole Junior Member

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    Did you start with the discharge?

    What makes you think it is overcharging? Note that you will need to charge beyond the rated capacity of the battery since the efficiency is something less than 100%, e.g. if you put 7200 mAhr in you will not get 7200 out. (I am seeing around 85% efficiency, i.e. a module might be charged with 7250 mAhr but will then only discharge 6100 mAhr.) For initial attempts, I charged to 7250 mAhr. The delta-V cut the charging off on about 1/3 of the modules. For the other 2/3, it charged to the 7250 cutoff. Since delta-V was not hit, those modules could have been charged further to get to their full capacity.

    Britprius typically uses 7250 and I believe that is what's used in sideways' lengthy thread. JeffD uses a cutoff of 7500 mAhr to get closer to the full capacity.

    The module should be charged well over 7.2V. The nominal cell voltage for NiCd is 1.2V and for NiMH it's 1.25V. However, a fully-charged cell will be more in the 1.4 to 1.5V range.

    So, you might not really have a problem.
     
  2. SEaton

    SEaton Junior Member

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    well this morning I checked the batteries and they were still charging, but their voltages were up at like 8.6V. I thought that was too high, maybe I was wrong.
     
  3. marcs_carhole

    marcs_carhole Junior Member

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    Saw in another thread that you stated you were having problems with your balancing. How about an update ...
     
  4. dirt657

    dirt657 Member

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    So in conclusion, you guys think it would be safe to charge at 5A and discharge at 3A or more?