s/v Ninaa Ootakii - Batteries and classic settings

[Vic]

 ...   AND,  speaking of battery monitoring devices,  including the MNWbJr,  they all give approximations of SOC,      with,  generally too little real data.

These devices do a good job of Counting Coulombs, (total Net Ah into and out of the battery), so on off grid systems which are recharged,  regularly, they can be fairly accurate.

Personally,  with our completely off grid systems,  which are generally fully charged on most days,  we use the WbJr's report of Net Ah,  in the morning,  and almost always ignore SOC reports  ...  but,  this is just me.

IMO,  setting the Wb to reset Net Ah,  each time that the Classic/s transition from Absorb,  to Float, makes the info provided by the Wb,  more useful.

Also,  FLA batteries are not very efficient,  particularly during Absorb.  The FLA banks here are about 75-77% efficient on most full charge cycles (opinions differ, on this).

OH, and Stone,  one of the screen shots that you provided,  shows that your Classic does not Temp Comp EQs.   Compenstion of EQs, helps reduce the chance of Thermal Runaway,  and it also provides better predictability of the EQ,  IMO.

Later,  Vic

[Stone]

WBRST changed from "No" to "Yes"

[boB]

Thank you Vic !

Stone, I hope you can measure the individual battery voltages..

Ya know...  IF one of the batteries are bad, it will stand out like a sore thumb most likely even without charging or discharging.

If they are ALL bad...  Well I guess that will be harder to compare with.  But for sure, while charging, feel the batteries to see if one of them is hotter or colder than the others.  Maybe use a glove too. 

But voltage alone should show what's going on.

[Stone]

"Compensation of EQs, helps reduce the chance of Thermal Runaway,  and it also provides better predictability of the EQ"

I'll turn that on when I get back to the boat.

So where do I set what, to clarify to the system that it's 75ish % efficient?

[Stone]

I'm guessing the system has been trying to overcharge for the last 3 years, and the constant draw made it less noticable. I'll try to grab voltages tomorrow morning.

[Vic]

Hi Stone,

IIRC, the setting for Temperature Compensation of EQ is in:
Charge>Temperature Comp>EQ,Yes.

Here is the Link for the WbJr Manual:
https://www.midnitesolar.com/pdfs/10-264-1_REV_F.pdf

Page 4 in this manual shows how to set the Battery Charge Efficiency.  Why not use 80% as a starting point  --  this is a fine point, at this moment.

Those battery voltage readings will be quite helpful.  Please note the Wb battery charge/discharge Amps at the time these batt voltage readings were measured.

Good Luck,  Vic

[Stone]

This looks like bad news, but I'm no expert.

My volt meter seems kinda stupid, cause it's wandering around a bit, but I have numbers

A few of these were higher on recheck, so those are the numbers I went with.

Topped the batteries (half gallon or so) and then:

 |[ 4.2 ][ 5.8 ][ 6.1 ][ 6.2 ]|+
-|[ 6.4 ][ 4.3 ][ 6.5 ][ 5.4 ]|

Classic reads: 65V/ 70W in, batt 23.5V, 3.2A
WBJ reads 2.5A in, 20 deg C, 872AH, 100% SOC

It's overcast and raining like hell here.

Set temperature comp to ON
Set battery charge efficiency to 80%

[boB]

This looks like bad news, but I'm no expert.

My volt meter seems kinda stupid, cause it's wandering around a bit, but I have numbers

A few of these were higher on recheck, so those are the numbers I went with.

Topped the batteries (half gallon or so) and then:

 |[ 4.2 ][ 5.8 ][ 6.1 ][ 6.2 ]|+
-|[ 6.4 ][ 4.3 ][ 6.5 ][ 5.4 ]|

Classic reads: 65V/ 70W in, batt 23.5V, 3.2A
WBJ reads 2.5A in, 20 deg C, 872AH, 100% SOC

It's overcast and raining like hell here.

Set temperature comp to ON
Set battery charge efficiency to 80%

I don't think that EQ is going to help here.  BUT I may be wrong.  You can try.

I would say that the 4.2V and 4.3V and maybe the 5.4V are the worse batteries.

The 5.8V battery is probably on the edge.

Raining and 65V input and 70 watts (display only shows output watts) won't help to get them up to equal voltage though.  What should be done, I think, to try to help these batteries, is to charge them individually at the 6V (7V) level with a separate charger and shore power.  Full absorb or maybe even EQ voltage for a few hours while watching the water level.  And I would start with those low low batteries first.  Go to an auto parts store or Harbor Freight if there are any around and buy one or two of the chargers that will do 6V/12V

If one of those batteries doesn't end up staying at the ~6.3V area after a few hours of EQ or Absorb charging, then that battery is more than likely, toast.

Vic and others, please re-read  what I just posted and comment on anything I have said wrong here.

I wonder why the voltages were changing with your meter ?  It might be that with the rain, there was a varying amount of power as well as loads on the boat turning on and off.

Thank you for those readings, Stone !  That helps a lot.

boB

[Stone]

The inverter is off.
Literally the only things connected to the bank are the classic 150 and the WBJ.

I'm guessing that the meter I'm using was picking up the incoming voltage fluctuations... (a hundredth of a volt is pretty fine detail for this sort of thing)

[Vic]

Hi boB,

The drifting voltage readings on the Multimeter is troubleing.  One wonders about some loose connections,  in the cables twix the batteries  ...  or perhaps it is just that,  at least some batts,  are high impeadance,  and the small charge current from the PVs in the rain is really varying that much due to some of the batts are no longer really batteries.

One could make up one string, using those batts that are closest to 6 Volts  ...  but,  each of these 6 V batts weigh about 120 Lbs,  so moving batts to make four of them close together,  might not work out  ...

One might wonder about the Multimeter,  too  ...  many wonderments.  I only have one dumb transformer-rectifier batt charger in the fleet of portable batt chargers here,  dunno how common are batt chargers with 6v capability. Am sure that Amazon has a flood of batt chargers,  probably most of them are "Smart",  and may not even turn on,  unless,  batt voltage is fairly close to spec,  and so on.

FWIW,  thanks boB,  for doing your above and beyond Tech Support on this Forum,  we all sure do appreciate your dedication, later, thanks, Vic

[Stone]

So I have no idea wtf it's trying to do.

This is an 870ah bank, and I can hear the batteries bubbling. :/

Guessing I should disconnect the panels until I get this figured out. :/

[Vic]

So I have no idea wtf it's trying to do.

This is an 870ah bank, and I can hear the batteries bubbling. :/

Guessing I should disconnect the panels until I get this figured out. :/

Hi Stone,

Your battery may be HOT,  still.

The 25 C temperature shown on the Wb Status screen,  is NOT the batt temp,  it is just the temperature of the Wb's circuit board.

IIRC,  one of the earlier series  of Classic screens, did show 1% batt Capacity change for every for every 1 degree C change in batt temperature.  This may be a bit on the high side, at least to me.Lemme look for suggested settings for this.
EDITto add:  My Classics use 0.3% per degree C, change in batt Capacity vs temperature change (FWIW).

AND,  during sunny days, what is the Classsic charge stage??
This Classic may be stuck in EQ,   IIRC,  an EQ will continue,  every day,  until the total EQ time is reached,  and the only time that counts,  is the time that the Classic spends at the voltage set as the EQ voltage.   I believe that the EQ is not reset at Midnite of the day that the EQ was started (when ARST is enabled).<

In the Classic's Temperatures page,  please check and report what this temp reading is for the battery.

That screen shot in your post of today,  there is about 34 Amps of charge current,  going into the batteries  ...  it is encouraging that the batteries can accept that amount of current.

Later, Thanks,  Vic

[Stone]

I disconnected the panels yesterday and let everything sit overnight.

7am this morning, here's the temp screen.

[Vic]

Hi Stone,

The batt temp looks fine.

With no charging for hours, and if the only loads on the batts,  other than the Classic's idle power,  if possible,  this is probably a great time to measure the terminal voltage of each batt,  and record/report them,  if possible.

Thanks, Vic

[Stone]

Okay, so system has been nothing but the classic 150 and the batteries, for around 24 hours.

A couple of these read lower, but climbed over the course of a couple of seconds... no idea what that means.

Old numbers:
-|[ 4.2 ][ 5.8 ][ 6.1 ][ 6.2 ]|
 |[ 6.4 ][ 4.3 ][ 6.5 ][ 5.4 ]|+

New:
 |[ 2.4 ][ 4.3 ][ 4.1 ][ 4.7 ]|+
-|[ 6.0 ][ 3.4 ][ 6.0 ][ 3.9 ]|

Note that they likely need water.
I'm starting to question the meter I'm using, so I'm going to try and borrow a better one.

I have a DeWalt bench charger here that says it'll do reconditioning, but it's 12v, so I'm uncertain as to the best way forward here.