Charge controller LVD warning during equalization

kansaskansas Solar Expert Posts: 100 ✭✭
I ran my IOTA DLS 45 today to equalize my battery bank. When I checked the specific gravity at the end of the third hour, the LVD warning light on my ProStar 30 CC was blinking. Any idea why the CC would sense a low voltage situation?

My Trimetric meter showed a 15.4 volt charge throughout the equalization.

The LVD warning quit blinking after I disconnected the DLS and restarted the system in the order Morningstar recommends: CC to battery circuit first, then PV to CC.

There is no DC load connected to the CC. The battery bank was certainly not low - the specific gravity was a pretty uniform 1.280 in five of the six cells, with the outlier at 1.255. The batteries were fully charged before I began the equalization. I didn't disconnect the solar input to the CC circuit, or the CC to battery circuit during the equalization, if that matters.

Temperature at the battery bank 50 F; equalization voltage 15.4. The battery manufacture suggests a periodic equalization of from 1 to 3 hours at 15.5 volts. At 50 F, the equalization voltage should have been more like 16 volts, but 15.4 is the maximum output of the DLS. The specific gravity of the weak cell did not change after three hours at 15.4 volts.

Thanks
Two 140 watt Kyocera panels, wired in parallel; Ironridge top of pole mount; two 6 volt, 242 AH US batteries, wired in series; Morningstar ProStar 30 charge controller and SureSine 300 inverter; Trimetric 2025-A meter; IOTA DLS-45 charger, Honda EG3500X generator; Aermotor 702 water pumping windmill.

Comments

  • scrubjaysnestscrubjaysnest Solar Expert Posts: 175 ✭✭✭
    My TS-45 also goes into alarm during an equalize with an external charger. I think you will find the CC's also alarm on high voltage.
  • kansaskansas Solar Expert Posts: 100 ✭✭
    You're right, scrubjaysnest, the ProStar sequences between red and green on HVD. Maybe I saw that and not just a blinking red (LVD warning). If so, that's a little easier for me, with my limited knowledge, to make sense of, but the voltage to the battery from the charger was a steady 15.4 volts the entire equalization and the warning signal didn't start until the the third hour check.

    Also, any ideas why the equalization had no impact on the battery specific gravity? Voltage too low? Not long enough? I was elated to get solid 100% charge readings of 1.280 on 5 of the 6 cells before the equalization. In the previous 9 months the readings among the six cells were more scattered and in the 1.23 - 1.26 range. US Battery, the manufacturer, specifies an SG of 1.270, minimum.

    Interestingly, the weak cell was one of the consistently stronger cells in my prior readings over the past several months ago. Several folks here suggested that it could take quite awhile for the battery plates to fully form and the SG to settle down. Maybe time will continue to make a difference.

    Thanks - Bill
    Two 140 watt Kyocera panels, wired in parallel; Ironridge top of pole mount; two 6 volt, 242 AH US batteries, wired in series; Morningstar ProStar 30 charge controller and SureSine 300 inverter; Trimetric 2025-A meter; IOTA DLS-45 charger, Honda EG3500X generator; Aermotor 702 water pumping windmill.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Using 15.4 to EQ is not a issue, It would just take a little longerand the temperature will rise on them. Cycle them for a while and see if that cell gets better. A option would be to get a old 6 v junk battery to pair up with the other so you could still use the IOTA and not hammer them all. I have had them take as long as 18 hrs to ever move the SG's up. Keep checking the weak cell for any movement. As long as it's moving your making headway. Keep a eye on the temperatures on the batteries and do not go over 115 F.
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