My Screwy 31

landyacht318 wrote:
Another Sunday
More Data
Since last report ABSV 14.7, 14.8 F
Checked SG once it went into Float/Finish today requiring 3 amps to hold 14.8
1.250 on all 3 cells

Raised both to 15.7v Took ~90 minutes for SG to rise to 1.280 and held there. Initial amps were 5.0, after 90 minutes were 4.1..

Another 45 minutes at 15.7, 3.9 amps and still 1.280.

Remembering I was able to exceed 1.290 last time I checked, and have not since added h20 I just now bumped voltages upto 16v.
6.4 amps are required to hold that voltageI just now bumped voltages upto 16v.
6.4 amps are required to hold that voltage 1 minute after changing the setpoints.

Yesterday was cloudy all day and only got to 20 A/h from full, even with some alternator assist.

So it appears the lower the setpoints, which are still pretty high, the longer the EQ session needed to restore SG to the Max.

Also If 16v does at least bring 1 of the 3 cells to 1.290 or above, then 15.7v is not adequate for EQing this battery.

All 3 of the easy to check cells are reading exactly the same at every dipping today.

I underestimated the electrolyte level last report. It is higher than half way below the split rings and plates.


On another note, one reason I cycled the AGM battery is I noticed it had lost a bit of its violent ability to crank the starter motor so rapidly.

The battery monitor was of little use, but My inline GTpower meter, similar to a Turnigy, recorded it required 56.4 amp hours before the Schumacher's green light came on, and it was taking 1.2 amps at 14.7v, when I disconnected it.

I had the Schumacher on the 25 amp setting. This higher recharge rate restored that extremely impressive ability Of this Northstar AGM to crank the starter motor so fast that the engine is just running at the merest blip of the starter. I do not think that just allowing it alternator and Vehicluar VR defined recharging parameters is sufficient to keep it at max energy density, and the low and slow solar, despite my week long cycling of it withut noticeable drop off in voltages under load, is also just not adequate.
It seems to follow into Odyssey's recommendation of a minimum 40% recharge rate,when deeply cycled, for max performance, which does not make it a great solar only recharge battery.

Okay time to go dip the Hydrometer again.

The emboldened text is a superb real-life example of the validity of the -correct- BCI (and me) endorsed formula to equalize flooded LA batteries. Time is money. Unless you have days and days to screw around while connected to shore power the 5% of amp hours until 16.0 volts is reached or when density on all cells reverts to OEM is rational. Trying to equalize at lower voltage is progressively more fruitless as tenths of volts are subtracted from the 16.0 volt end point.

POINT!

Use a 120 watt rated DC to DC boost converter to whack a single sulfated battery,

OR

Tap into a SINGLE solar panel, use diodes in series to limit OCV to 16.0 and then run a BYPASS CIRCUIT with switch to deliver equalization power. Connect this through a spring wound timer if you are forgetful. This works with lower voltage panels. Higher voltage panels use a BUCK converter to drop voltage to 16.0 volts.

These BUCK / BOOST converters are like 100,000,000,000,000,000,000,000 times easier to learn and use than a computer or TOOBLOOTH accessory.