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bighatnohorse's avatar
bighatnohorse
Explorer II
Sep 14, 2020

15.2 v during solar equalization charge - what do you do?

I'm reading the operation manual for the BLUE SKY ENERGY SB3000i
It reads:
the 3000i will perform an automatic equalization at the factory default settings of 15.2V for 2 hours every 30 days which is typically suitable for most flooded lead-acid batteries


It also reads:
The maximum setpoint voltage limit places a maximum limit or ceiling on the charge voltage setpoint used by the 3000i in all charge modes to prevent inverters or other equipment from shutting down due to excess voltage. Regardless of initial setpoints, charge mode or temperature compensation the 3000i will not use a charge voltage setpoint greater than the maximum setpoint voltage limit (uPr) factory set to 15.5V.


This could be dangerous for sensitive equipment and I'm what those of you who have solar power systems do on your RV to handle this potential problem?
  • I used to twist a six-hour timer and shut sensitive loads off. Normally closed relay. Then I spent a fortune and purchased a pair of 24 volt refrigerator freezers. They handled 30.2 volts just fine.
  • jkwilson wrote:
    StirCrazy wrote:
    if you have a deicent fuse set up it will be filtered dc current so you realy dont need to worry about it.

    Steve


    A fuse performs no filtering. It’s just a wire, and even if it did that would have no effect on the voltage.


    yup thats true, but the electronics in my power centre do have dc filtering.. the max DC voltage it will put out is 13.6 at no load and it will maintain over 12.6 at full load. it also has electronic current limiting.

    Steve
  • StirCrazy wrote:
    if you have a deicent fuse set up it will be filtered dc current so you realy dont need to worry about it.

    Steve


    A fuse performs no filtering. It’s just a wire, and even if it did that would have no effect on the voltage.
  • Hi BigHatnohorse,

    The computer boards in RV's dc systems are safe up to 15.4 volts.

    I have the Blue Sky 3024 di. I've never had a problem with over voltage. the unit is set to 15.2 volts for equalization.

    Time2roll the Blue Sky has extremely limited adjustment via dip switches. They sell a separate "calibrator" called an IPNPRO remote for fine tuning. It, unfortunately, costs nearly as much as the charge controller itself. Your Morningstar is a much better buy.

    There is a dip switch setting to turn equalization off.
  • if you have a deicent fuse set up it will be filtered dc current so you realy dont need to worry about it.

    Steve
  • Norcold (and maybe Dometic) fridges have a high voltage limit of 15.4v, so 15.5v is over that (especially if temperature compensated even higher when it is cold out)

    Yes, as others said, turn it off. Use it only as needed and when you have separated the batts from the rest of the system.
  • Magnum inverters handle up to 17 volts DC. Outback also handles up to 17 volts DC. I suspect others are similar. The bigger question is do you have flooded batteries that need to be equalized or do you have AGM batteries that shouldn't be equalized.
    You can turn off the auto equalization function, I think it's DIP switch #5. That's probably the simplest solution. One of the main reasons for an equalization charge is to "stir" the electrolyte to prevent stratification. That's hardly needed in an RV where the batteries are constantly bumping and bouncing down the highway.

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