P30L bulk and float voltage

Discussion in 'Charge Controllers' started by shawnrdeleon, Aug 12, 2017.

  1. If the P30L is set to charge at 13.8v what is the bulk charge voltage?

    Can you break down the three charging phases and what each voltage is?

    How does changing the voltage in the controller change the other stages of charging?

    I just switched my P30L to charge at 14.6v but now realize that should be the bulk voltage.
  2. Tuicemen

    Tuicemen Solar Guru

    I would have thought that info would be in the manual however I see it isn't.
    Since I don't run one of these chargers I'll see if I Can dig up some info.
    It looks to me that the charging phases are all predetermined based on the charge setting.
    Windynation may chime in here with some specific details.
    shawnrdeleon likes this.
  3. Tuicemen

    Tuicemen Solar Guru

    Modern multi-stage charge controllers
    Most quality charge controller units have what is known as a 3 stage charge cycle that goes like this :
    1) BULK : During the Bulk phase of the charge cycle, the voltage gradually rises to the Bulk level (usually 14.4 to 14.6 volts) while the batteries draw maximum current. When Bulk level voltage is reached the absorption stage begins.
    2) ABSORPTION : During this phase the voltage is maintained at Bulk voltage level for a specified time (usually an hour) while the current gradually tapers off as the batteries charge up.
    3) FLOAT : After the absorption time passes the voltage is lowered to float level (usually 13.4 to 13.7 volts) and the batteries draw a small maintenance current until the next cycle.
    This still doesn't help with what the charge setting should be set at however this post http://forums.windynation.com/community/threads/p30l-absorption-phase.3341/
    should provide some help;)
    shawnrdeleon likes this.
  4. WindyFAQ

    WindyFAQ WindyNation FAQ Staff Member

    That is correct, the OVD setting should be set to the Float charge specified by your battery manufacturer.

    What happens is that for bulk/boost charging, it will keep charging for approx 30 mins and then move to Equalize. The third and final stage will be float. Once the voltage is close to the float voltage (OVD), small current will be pulsed to the battery and the voltage will not increase.
  5. Ok, thanks. What are the different voltages for each stage? Do those change based on the ovd voltage? How so?
  6. WindyFAQ

    WindyFAQ WindyNation FAQ Staff Member

    Yes, the values will change based on the OVD (Float) setting, where this is the only fixed value

    The duration for bulk is preset and is approx 107% of the OVD. The controller will then measure the battery and initiate Equalization and Float stages accordingly
  7. I didn't want to start a new thread for this one question but for LiFePO4 batteries with a 14.4v - 14.6v upper charge rate, does that mean the OVD should be set at 13.6 x 107% = 14.55??? Isn't 13.6 the default OVD rate? I just hooked my P30L up and is it already default set for LiFePO4?
    Last edited: Oct 7, 2020

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