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incorrect battery AH Reading.. Need help

Started by skylab, August 04, 2015, 11:45:50 AM

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skylab

Hello everyone, i'm searching for some help in the form of an explanation of sorts.
I have a battery bank (8) Trojan T105RE, connected as 2 banks of 4, for a 24V 450AH battery , i also have another 400W of panels through another CC connected to the bank.
a whizbang Jr on my Classic 150. i have 1000W in panels wired in series. yesterday at the end of the
day my SOC was 88, I turned my classic off and on and when it finished booting up it showed my SOC as 42
i'm lost as to why this is happening and i can no long ascertain weather or not my batteries are being fully charged anymore
i went from being charge to 100% withing about 4hrs to not reaching 90 anymore , my loads hasn't increased
and my batteries are only about 5 months old. why am i not getting correct reading from my CC.

Westbranch

#1
what are your other charge parameters?  Especially check the voltage showing on the MNGP an din the Local App
KID FW1811 560W >C&D 24V 900Ah AGM
CL150 29032 FW V.2126-NW2097-GP2133 175A E-Panel WBjr, 3Px4s 140W > 24V 900Ah AGM,
2 Cisco WRT54GL i/c DD-WRT Rtr, NetGr DS104Hub
Cotek ST1500 Inv  want a 24V  ROSIE Inverter
OmniCharge3024  Eu1/2/3000iGens
West Chilcotin 1680+W to come

Vic

sky..,

The real measure of what is the State Of Charge (SOC) of your battery is to use your Hudrometer,  and actually measure,  at least your Pilot Cell.

IMO,  Battery Monitoring devices are a quick approximation of the Remaining Capacity,  and SOC.

Believe that the data on C and SOC is stored in RAM,  and you  probably will need to complete a full charge cycle,  and transition to Float for the C and SOC data to be updated ...   my guess anyway.

FWIW,  Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

Halfcrazy

If you shut off the classic it will loose its calibration for the SOC. It will however recalibrate after a full charge.
Changing the way wind turbines operate one smoke filled box at a time

Halfcrazy

Also you say you can not get the batteries full any more? So the Classic is not going to Absorb or float anymore?
Changing the way wind turbines operate one smoke filled box at a time

boB

I am also very interested in what might be going on here.

boB
K7IQ 🌛  He/She/Me

Jacotenente

Ditto...mine is not working right after increasing my battery bank size (went from 370 to 740 amp/hours). After a full charge, the Classic reads 100% and amp/hours left about 675 or so. These are brand new Trojan L16 batteries, temps were about 75 deg F. Someone said to disconnect the purple wire, re-input the amp/hour parameters, hit some arrow keys or something, and it will read correctly (SOC and amp/hours left). NEED this to work correctly...thanks.  -Chris

Vic

#7
Hi Jaco..,

There are several factors that affect the AH Remaining.  Battery temperature is one.

In the Temps Menu (if you have a standard Classic),  you can see what the Classic reads as the battery temperature.  The batteries may be cooler than you think.   Battery temps have a fairly large effect on Capacity  --  and this factor is one that you can set in the set-up of the WBjr.

The SOC,  AH remaining will reset then the Classic charge state transitions to Float,  BUT,  the AH Remaining  will still be affected by the measured battery temperature.

SOC  should be accurate at the transition to Float,  but the parameters that YOU have chosen,  and set  for your batteries will begin to affect SOC and AH remaining from that point on will affect the reading on SOC AH remaining.  There can be fairly large drift in the accuracy of those values,  until the next transition to Float,  when the SOC should be fairly accurate.

In general,  these values that the WB allows the Classic to display are estimates,  and,  IMO,  should not be taken as absolutes,  just approximations,  or rough approximations,  based on the values that you have chosen for parameters.

The WBjr can accurately measure  AH coming into and removed from your battery,  BUT,  the effect that these currents have on the ACTUAL SOC and AH remaining are not constant.  If one removes a large amount of current in a short time,  the actual SOC  will be lower than if the same total amount of current is removed at a lower rate,  and so on.  And,  this factor will differ from one battery to another.

There are many variables regarding battery SOC and AH remaining that the battery user cannot know very exactly,  and that are affected by a number of other factors that are difficult for us to define.

The WBjr is a great,  and inexpensive addition to the Classic.   But,  expecting for any battery Monitoring device to show actual SOC and AH remaining to be absolutely accurate,  will often disappoint the user.

Your young batteries will need a number of discharge/charge cycles to attain their advertised AH Capacity,  and this is just one additional factor that is difficult for the battery user to know,  and be able to accurately set into a battery monitoring device.

All just my opinions.   Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

Resthome

Quote from: Jacotenente on November 04, 2015, 05:50:25 AM
Ditto...mine is not working right after increasing my battery bank size (went from 370 to 740 amp/hours). After a full charge, the Classic reads 100% and amp/hours left about 675 or so. These are brand new Trojan L16 batteries, temps were about 75 deg F. Someone said to disconnect the purple wire, re-input the amp/hour parameters, hit some arrow keys or something, and it will read correctly (SOC and amp/hours left). NEED this to work correctly...thanks.  -Chris

What do you have the WBjr temp reference and % of capacity change values set to?
John

10 x Kyocera KC140, Classic 150 w/WBJr, Link10 Battery Monitor, 850 AH @ 12v Solar One 2v cells, Xantrex PROwatt SW2000
Off Grid on Houseboat Lake Don Pedro, CA

Jacotenente

Hi John (and thanks Vic) - Here is what I have it set at:

Temp Compensation: -5 mv/ deg C/cell
Temp Window: 25 deg C

Battery Status Meter Efficiency: 94%
Capacity: 740 Ah
Compensation: 1%/C

I am running two standard Classics in "Follow Me" mode.

Thanks.

Resthome

Has the Classic gone from Absorb to Float?  It's possible to get 100% SOC before all the AH have been put back in. What does the battery Temp say in the Temp Menu? There is also check box in the LA about going to 100% when going from absorb to float.
John

10 x Kyocera KC140, Classic 150 w/WBJr, Link10 Battery Monitor, 850 AH @ 12v Solar One 2v cells, Xantrex PROwatt SW2000
Off Grid on Houseboat Lake Don Pedro, CA

Jacotenente

Thanks. Battery temp is 22C and that box is checked for both controllers in the Local APP.

Chris

Resthome

Set the percentage of capacity lost or gained for every degree C to 0% and see what you get that will temporary disable the temp compensation for AH remaining.

You did not indicated if the Classic has made a complete charge cycle, Bulk, Absorb, Float.

I guess if End Amps is set that it could be going to Float too soon and the SOC would go to 100% when it goes to Float.
John

10 x Kyocera KC140, Classic 150 w/WBJr, Link10 Battery Monitor, 850 AH @ 12v Solar One 2v cells, Xantrex PROwatt SW2000
Off Grid on Houseboat Lake Don Pedro, CA

Jacotenente

Quote from: Resthome on November 04, 2015, 09:29:29 PM
Set the percentage of capacity lost or gained for every degree C to 0% and see what you get that will temporary disable the temp compensation for AH remaining.

You did not indicated if the Classic has made a complete charge cycle, Bulk, Absorb, Float.

I guess if End Amps is set that it could be going to Float too soon and the SOC would go to 100% when it goes to Float.

Will do...thanks. And, yep, been through a bulk-absorb-float cycle with these batteries. What are your thoughts on "Water Miser" battery filler caps? You know, the yellow ones. Thanks again for your help. -Chris

Vic

Quote from: Jacotenente on November 06, 2015, 08:32:38 AM
   ...    What are your thoughts on "Water Miser" battery filler caps? You know, the yellow ones. Thanks again for your help. -Chris

While this question was NOT directed at me,   ...

Have used Water Miser caps for some years on some 1280 AH Surrettes.  The Water Miser caps ooze electrolyte,  after a period of time  --  much more so than the standard bayonet caps as supplied by the manufacturer.

The WM caps also become plugged (probably with crystalized H2SO4),  and this causes a mild pressurization of these cells.

For  your L-16s,  the WMs MIGHT,  possibly,  offer some benefit,  as  the electrolyte Reserve volume is fairly small on L-16s,  vs the Surrette 5000-series batteries in use here.

Also,  believe that there are three available heights on the WMs.  If you could accommodate extra height above the battery,  would suggest choosing the tallest WM you can use.

But for my application,  the WMs are WORSE than standard caps,  and have noticed absolutely no reduction in water use on banks that use WMs and those that use standard caps.

On balance,  however,  the batteries using WMs here are 1280 AH nominal Capacity,  so,  one would expect that volume of gas passing through the WMs would be about four-ish times that of a standard L-16.   Although,  your batteries probably run at least 1.280 SG electrolyte,  which  would probably result in  a bit more gassing than batteries with 1.265 SG electrolyte (due to probable higher Absorption and EQ voltage required for higher SG electrolyte).

Just my experience.  And,  the one L-16 bank in use here does not use excessive water,  and does not splatter the battery tops with electrolyte vapor/drops to any large extent.

FWIW,   Opinions,   Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!