S/V Ninaa Ootakii - system startup (2x classic 150's @ 24v)

[boB]

Thank you Vic !   

I will have to look at those documents sometime.   For now, people are at least free to choose.

I'm sure there are enough variables like age and actual battery capacity that change this.

And some flooded LA batteries are just different like whether they are lead antimony or calcium and how fast they charge and discharge.

I would probably trust the Sandia report having been there and seeing how they operate.

But in the end, the battery manufacturer has the last word.   

[Stone]

Well, I clearly screwed something up, 'cause my available amp hours is going down, not up, and literally nothing is running except the classic 150 and the WBJ.

... that deka pdf was as clear as mud
I don't have the math for it.

These batteries are brand new, and I don't want to screw them up, but I can't find anything that even appears to be close for what they're supposed to be set to

[Stone]

I found the charging manual!

And literally all it says is

"The maximum constant current rate in amps should be approximately 20% of the amp hour rating of the battery."
*sigh*

Looks like the actual manufacturer may be johnson controls...
*googles more*

[Stone]

So I just hit 100% State of Charge, and the system clearly thinks my batteries are 364 ah.
*sigh*

[boB]

Has the Classic done a complete Absorb cycle for 2 hours or whatever ?  That is necessary in order to believe the
SOC reading on the main status screen.  In the WB Jr. screen the SOC% would be flashing if you had not gone through a timed Absorb.

Do you have a battery hydrometer meter to test the electrolyte ?  These are the kind with a water fill cap, right ?

Are these Interstate batteries ?   Those are probably made by Johnson Controls except I hear that their golf cart
batteries are made by Trojan right now.  Or they were....

[ClassicCrazy]

Well, I clearly screwed something up, 'cause my available amp hours is going down, not up, and literally nothing is running except the classic 150 and the WBJ.

... that deka pdf was as clear as mud
I don't have the math for it.

These batteries are brand new, and I don't want to screw them up, but I can't find anything that even appears to be close for what they're supposed to be set to

set your absorb setpoint to 28.8v  absorb time to 2 hours Set  float to 27.6 v 
You won't go wrong with that .
Look again in the Deka info I posted - it says right there.
The other thing you mentioned was the maximum charge rate of 20% of capacity . You don't have to worry about going over that because I don't think it sounds like you have that much pv to do it anyway. Once it gets to Absorb setpoint it would cut back charge current anyway.

Larry

[Vic]

So I just hit 100% State of Charge, and the system clearly thinks my batteries are 364 ah.
*sigh*

Hi Stone,

Couple of comments,   first,  if the batteries are located near the Classic,  much of the reduction in Remaining Capacity,  to 364,  probably results from the batteries being cold.  As,  you have changed the compensation value of battery Capacity to 1%.   The difference in temperature from the standard reference battery temperature of the typical value of 25 degrees C,   to the 11 degrees C reading on the WbJr status page results in about 14% reduction in the nominal 435 Ah rating at 25 C.   It is possible that the actual battery temperature is considerably different than that shown on the Wb readout (this temp reading is taken at the Wb circuit board)   ...   but  14% reduction of 435,  is about 374.

Good that you found the manual for your batteries.   If your batteries are Flooded type,  the three top caps on each battery are easily removable,  with a simple twist.   Would guess that your batteries are Flooded.

There are quite a few details in managing battery based systems.  Flooded batteries are quite tolerant to settings not being just right for the use that they experience.   They do not like to run low on water,   and when at a very low State Of Charge (SOC),   cold temperatures can freeze the electrolyte,  which will KILL them.

What is the Absorb time setting in the Classic?   The End Amps setting of 14-sih Amps may be a bit high for two parallel strings of 435 Ah batteries,   but,   IIRC,  Larry mentioned how to watch the WbJr battery current,   during Absorb to help dial in that setting.

It IS good,  that you are paying attention to your new batteries,   they LOVE attention!

Later,   Vic

[boB]

Also, sometimes batteries when brand new do not have the full rated capacity until they've been cycled or run several times.

I think that Rolls says 100 or so cycles for their FLAs.

Also, one thing you will want to watch is that when you have the WB Jr. end the Absorb cycle, it MAY allow the batteries to NOT get a full Absorb cycle once in a while which is important so the batteries do not sulfate.

As Vic mentioned, make sure the Ending Amps is set correctly but you will want to ensure the batteries are allowed to get a good timed Absorb once in a while.  Maybe once or twice or more per week ?

[Stone]

Okay, the manual for my batteries isn't actually a manual, it's not even a good joke.

That said, the Trojan L16HAC weighs the same and has the same rating...
It's numbers look reasonable to me.

I have 4 L-16's in series for 24v.
They're in an unheated space, and the WBJ is about 2 feet above them in the same space, and it says 11⁰C.

Do these numbers look reasonable?

[Vic]

Hi Stone,  Thanks for the added info.

The two tables that you posted,  should be a good starting point,   IF  your batteries are Flooded  --  these will have three easily-removed caps on the battery top.

You will want to get a good quality Hydrometer,  to measure the Specific Gravity (SG),  of each cell in each battery.   Some Auto Parts stores will have a reasonable quality glass Hydrometer,  with a squeeze bulb on top,  and a small hose on the bottom.  Find one that has NUMBERS for the SG values,   NOT just colors,  or colored balls.

MidNite distributes a good Hydrometer,  the Hydrovolt (r),   that is available from Solar equipment sellers:
https://www.solar-electric.com/midnite-solar-battery-hydrometer.html?msclkid=374af888e0fc1629911fa751e864e1cf&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping%20-%20All%20Products&utm_term=4588536901185467&utm_content=All%20Products

(an insanely long Link,  which may not work   ...)

More later,   Vic

[ClassicCrazy]

Hi Stone,  Thanks for the added info.

The two tables that you posted,  should be a good starting point,   IF  your batteries are Flooded  --  these will have three easily-removed caps on the battery top.

You will want to get a good quality Hydrometer,  to measure the Specific Gravity (SG),  of each cell in each battery.   Some Auto Parts stores will have a reasonable quality glass Hydrometer,  with a squeeze bulb on top,  and a small hose on the bottom.  Find one that has NUMBERS for the SG values,   NOT just colors,  or colored balls.

MidNite distributes a good Hydrometer,  the Hydrovolt (r),   that is available from Solar equipment sellers:
https://www.solar-electric.com/midnite-solar-battery-hydrometer.html?msclkid=374af888e0fc1629911fa751e864e1cf&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping%20-%20All%20Products&utm_term=4588536901185467&utm_content=All%20Products

(an insanely long Link,  which may not work   ...)

More later,   Vic

Vic,
Aren't those voltages for absorb on the high side ?

Larry

[Vic]

Hi Larry,

IMO,  the charge voltages depend on the SG of the fill electrolyte,   and the plate construction.

Most HC(High Capacity) batteries have 1.280-1.285-ish SG electrolyte when fully-charged,   which is a bit above most batteries,  designed for solar charging.

The Temp Compensation value,  may be an important thing that is still kind of an unknown.

Seemed,  that in the absence of definite information,  the Trojan voltages are not a bad place to start,   when armed with a good Hydrometer.

More later,  thanks Larry for all that you do for all of us here.   73   Vic

[Vic]

Will add a couple more things,

Hi Stone,

First question:
Do the tops of your batteries each have three easily-removed caps ?  ??

The seller of those Interstate batteries that you have,  does owe you specific Charging parameters.

Suggest that you ask them (ideally), for:

1.  Charging voltages from Solar.
2.  The Specific Gravity reading for full charge.
3.  Finishing Current (also known as EA),  for a complete charge.  This is usually a percentage of 20 Hour Capacity.
4.  The manufacturer of these batteries.  (this might help fill in blank spots in the above).
5. Temperature Compensation value for charge voltages.

The above info will help you save some time and heartache in getting a handle on how to charge your batteries.

Later,   Good Luck,   Vic

[australsolarier]

lead acid batteries efficiency of 94%?
i think you are skating of very thin ice here.
then we have the absorption cycle which reduces available solar power.
then that high peukert factor.
highish self discharge.
and using some amps to just keep in float.
if all those things are considered, i think we will be lucky to get 80% efficiency. just my ten cents

[ClassicCrazy]

lead acid batteries efficiency of 94%?
i think you are skating of very thin ice here.
then we have the absorption cycle which reduces available solar power.
then that high peukert factor.
highish self discharge.
and using some amps to just keep in float.
if all those things are considered, i think we will be lucky to get 80% efficiency. just my ten cents

I think Vic was referring to higher efficiency for sealed lead acids - like agm and gel types. Mine seem way up there in 90's  - they don't have so much loss of what comes out compared to what goes back in .

Larry