Wiz bang JR settings

[n4zi]

  I have been up 2 weeks tomorrow! The Whizbang JR seems to work quite well. I have watched it as the sun
comes up and slowly the reading will switch from negative to positive when there is descent sun. I have 2 banks
of 220 ah battery banks @ 48VDC  - 440ah total. when it says that I am at say 95% SOC how do I know that this
is accurate? I have noticed a gradual drop in my hydrometer readings this past week - I'm not sure what is causing
this - yet the SOC seems to be par and battery voltage correlates with standard chart that I found. US battery calls
for a float voltage of 2.17 per cell or 52.08 on a 48 vdc system. Yesterday I thought this might be low so I upped
the float voltage to 54.4 volts. I have also noticed that the Classics go resting from time to time when I have full sun.
Of course there is very little load when I am not out doing something in my shop (less than 100 wts per hr) So my
question is am I on the right track by raising the float voltage? What affect does the End amps have on charging?
What other settings should I be looking at for the whizbang?

  Thanks for your help,  73

    Bill  TN

[Mtn Don]

A good hydrometer with temperature taken into account will give the most correct insight as to battery state of charge. If the weather has been sunny and the sp. gr. readings have been slowly falling it sounds like the batteries are getting insufficient absorb charge.  Battery voltage readings can and do lead to false assumptions about state of charge. For voltage to be close to providing a true battery charge indicator there should be no discharge and no charge for several hours. An overnight rest with no loads and all charge sources disconnected will usually give sufficient time for the voltage to stabilize. As you get used to the performance over time and different seasons the voltage can be an indicator that is useful. A good hydrometer is still the best method. One of these works well for me.

[Vic]

Hi Bill,

Battery Monitors are a good,  rough indication the SOC of batteries.  They know a few things about the charge and discharge of the batteries that they and connected to,  but it is very difficult to make them fairly perfect.

The good news for you is that they are Flooded batteries,  and you can actually measure the SG,   to determine the actual SOC.  These measurements could help with the calibration of the WB's readings.

Usually,  hhere,  only look at the Net AH reading in the morning,  to see just how deeply the battery had been discharged since the last full charge,  and that is all that I need.   It is possible to get a bit wound-up in trying to make the readings nearly perfect.  If this IS accomplished for a given set of parameters,  then something will change that can make the accuracy diverge from measured SG via the Hydrometer.

Batteries often need a bit of cycling to establish full capacity,  and this can affect the accuracy of the WB (or any other battery monitor),  as can charge and discharge rates,  the DOD in the previous cycle,  battery aging and so on.

If you feel that your batteries are not being fully charged,  then the first knob to tweak is often the Absorb time,  and perhaps the Absorb voltage.

Batteries can be charged by Floating them,  but  it is a slow process,  and the Float voltage is usually below the Gassing voltage,   so there is little mixing of the electrolyte in Flooded batteries.  So,  personally would reduce the Float voltage,  and try to increase the Absorb time,  or perhaps reduce the Shunt Ending Amps that the WB can communicate to the Classic,  to end the Absorb.

So,  you are using the Remote Temperature Sensor with all charge sources?

Have you set the Temperature Compensation to --5 mV/cell (this is the customary setting for Flooded batteries)?

And please also check the Limits sub-menu in the Charge menu.  Make certain that you have compensation Limits that are wide enough for Flooded batteries.  It appears that the newer Firmware defaults these limits fairly narrowly -- probably attempting to protect SLA batteries.   BUT,   IMO,  these settings are much too narrow for Flooded batteries.   It IS nice to have this flexibility to limit charge voltage excursions,  especially when using Inverters that have limited ability to operate with high charge voltages required by cold batteries,  and so on.

FWIW,   just opinions and a bit of an editorial comment.      73,  GL  es HNY.   Vic

[boB]

Vic !  Thank you for reminding me about the charge voltage limits.  Those really should be a bit wider, or at least the high voltage limit.

boB