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Whiz Bang Jr. Capacity reading accuracy

Started by mohbbb1985, July 21, 2018, 02:50:18 PM

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mohbbb1985

Hello all,

I got 6 * 320w solar with 24v deep cycle battery bank(4 of 6v US REL16 XC) and Midnite 150 classic charge controller. My question is about the Whiz Bang Jr. capacity reading. The whiz bang jr.. show the remaining battery charge is %65 while the battery voltage is 23.6v. That doesn't sound correct to me. I'm wondering if those readings are accurate or not? Please see attachment.

Thank you !

Westbranch

Is that Graham's Android version of the Local App?  it sure looks like it.

You either have to use the MNGP or the MidNite Local App for windows to set the battery and charging parameters.  Did you set those?

You can not do it with Graham's 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

mohbbb1985

Quote from: Westbranch on July 21, 2018, 04:17:05 PM
Is that Graham's Android version of the Local App?  it sure looks like it.

You either have to use the MNGP or the MidNite Local App for windows to set the battery and charging parameters.  Did you set those?

You can not do it with Graham's App!

Yes. Its Graham's app. I'm using this app to view the numbers. I already set things on the charge controller using the charge controller panel.

Westbranch

Do you have a PC so you can use the Local App, as it is much easier to review and set/reset any value
IIRC you can see all the battery factors on one 'page'...
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

ClassicCrazy

#4
If they are new batteries you need to cycle them a few times first to break them in to their full capacity. Vic has talked about that in other forum posts.

What do you have set for the capacity and the efficiency for the Whizbang settings on your batteries ?
When the batteries get fully charged ( to their Absorb setpoint for either Absorb time or ending amps if you have that set ) when they go to float the SOC will go to 100%/

So if you have not fully charged your batteries then the SOC will continue to go down as will the voltage too.
So the question is have  your batteries received a full charge ? Also have you confirmed testing batteries electrolyte to find out if they are fully charged to 100% that specific gravity is at manufacturers point of full charge ?

The whizbang SOC is only accurate if you set it up correctly and sometimes it needs tweaking as the batteries age too. But yes it can be a very good estimate of where the batteries are at  for SOC.

Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

ricardo

was that voltage reading under load or with no load? ..

mohbbb1985

Quote from: Westbranch on July 21, 2018, 09:04:50 PM
Do you have a PC so you can use the Local App, as it is much easier to review and set/reset any value
IIRC you can see all the battery factors on one 'page'...

Yes, I do have the local app. It's great ! both apps are reflecting the same numbers though. I only like the android app cause I can check on the system while am anywhere in the world.

mohbbb1985

Quote from: ClassicCrazy on July 21, 2018, 10:11:23 PM
If they are new batteries you need to cycle them a few times first to break them in to their full capacity. Vic has talked about that in other forum posts.

What do you have set for the capacity and the efficiency for the Whizbang settings on your batteries ?
When the batteries get fully charged ( to their Absorb setpoint for either Absorb time or ending amps if you have that set ) when they go to float the SOC will go to 100%/

So if you have not fully charged your batteries then the SOC will continue to go down as will the voltage too.
So the question is have  your batteries received a full charge ? Also have you confirmed testing batteries electrolyte to find out if they are fully charged to 100% that specific gravity is at manufacturers point of full charge ?

The whizbang SOC is only accurate if you set it up correctly and sometimes it needs tweaking as the batteries age too. But yes it can be a very good estimate of where the batteries are at  for SOC.

Larry

Hello Larry,

Thank you for your reply.
Those batteries are one year old. I haven't set the capacity and the efficiency settings (Didn't even know that I need to set it). I let Whizbang to figure it out automatically :D.
The SOC will show %100 when the batteries are fully charged, so yes, the batteries has received full charge. I've tested the batteries electrolyte (Getting about 12.75 each cell) and they are getting to manufacturers point of full charge.

So, Am I right that the %65 SOC isn't accurate since the voltage is below 24v? I saw couple charts online that shows the state of charge according to the battery voltage. Like this one:

https://modernsurvivalblog.com/wp-content/uploads/2013/06/battery-state-of-charge.jpg

mohbbb1985

#8
Attaching the electrolyte reading at %65 SOC

boB


You need to set the capacity in the Classic first.  Efficiency too but that might be almost correct as is.  Around 95% efficiency default.

The capacity might be close actually.   The default I seem to remember is 400 amp-hours but you should probably check.

boB
K7IQ 🌛  He/She/Me

ClassicCrazy

#10
Quote from: mohbbb1985 on July 21, 2018, 02:50:18 PM
Hello all,

I got 6 * 320w solar with 24v deep cycle battery bank(4 of 6v US REL16 XC) and Midnite 150 classic charge controller. My question is about the Whiz Bang Jr. capacity reading. The whiz bang jr.. show the remaining battery charge is %65 while the battery voltage is 23.6v. That doesn't sound correct to me. I'm wondering if those readings are accurate or not? Please see attachment.

Thank you !

If your batteries are that low it means that you either don't have enough PV to charge them every day or that you run too many loads for the battery capacity you have or you  just had a series of low light days so the batteries are not charged.

I believe Vic recommends around 85% efficiency for flooded lead acid batteries. You have to figure it out by watching when the  SOC says it gets to 100% and then check the SG reading to confirm that the cells are 100% . You can tweak the efficiency and capacity to get it to match the batteries performance the best .

Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

boB


After the batteries have been broken in and "about" at label capacity, whatever that really is, you can measure the capacity.

You have to first charge the heck out of them, let them absorb for a few hours, (watch the water level while doing this), and then run them down until the specific gravity or voltage tells you approximately what the batteries' SOC is...  Note the amp-hours removed since you started the discharge...  Don't discharge too hard though.  Maybe at approximately the discharge rate the manufacturer specifies they are rated at.

If measuring SOC using battery voltage, make sure the load isn't very high at that time or maybe disconnect the battery for a little while and let that voltage settle.

Could also discharge to maybe 50% and then extrapolate.   Or down to 75% or something other than exactly 0%.  You can normally discharge down to 0% but don't want to make a habit of it.

Would love to see software that just did this automatically.  Could be done if given a bit of time which we don't have at the moment unfortunately.

boB
K7IQ 🌛  He/She/Me

Vic

#12
Like many things regarding batteries,   there seem to be quite a number of variables,   perhaps more so,  with Flooded Lead Acid (FLA)  batteries.

I am no battery expert,  like most of us,   have dealt with FLA batteries for some years.

Most manufacturers state that for FLA (usually Lead-Antimony),   the nominal Ah Charge Efficiency   is   about 85%.    Adding insult to the injury of this relatively low number,  is,  that even this efficiency  is on the high side.

As FLA batteries become more fully charged,  the Ah charge efficiency continues to drop. 

For our off grid PV charged systems,  we tend to cycle batteries between about 70 or 80%  SOC and full charge.   This range could result in efficiencies below about 60% for common FLA batteries,  with Lead Antinomy construction.

Gassing  for these batteries is probably the main factor in the reduction of Ah charge efficiency at the top end of the SOC range.

In answer to the question about the correlation of measured battery voltage and SOC,   as was stated above,   it all depends.   The chart in the Link,  appears to only apply mostly,  to number of Trojan batteries (with 1.277 SG at full charge),   and as was noted by boB,  that chart is probably only applicable to a Rested battery (no charge or discharge for many hours).   So given the data that is available,  it is hard to tell about the accuracy of the WbJr SOC report,  verses the battery voltage (and just what the battery had experienced in charge/discharge in the previous hours.

It has been noted that,  AGM batteries may well have Ah Charge Efficiencies in the range of 90%+,  perhaps about 94%,   but have not ever used AGMs.   Believe that SGs in AGMs are set high,  so there is relatively little gassing inside, at reasonable Absorb voltages   and the catalyst in the caps does not need to work too hard  ...   just guessing.

All IMO,   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!!

boB

I haven't seen an Amp-Hour efficiency number of 85% or lower.  However, I DO know that Watt-Hour efficiencies are lower than 85%.

W-H efficiency being lower because of the energy needed to Absorb.  If you don't Absorb every day, then that efficiency might be higher.

You sure you mean A-H efficiency and not W-H efficiency, Vic ?   Would love to hear more.

boB
K7IQ 🌛  He/She/Me

Vic

Quote from: boB on July 27, 2018, 04:13:31 PM
I haven't seen an Amp-Hour efficiency number of 85% or lower.  However, I DO know that Watt-Hour efficiencies are lower than 85%.

W-H efficiency being lower because of the energy needed to Absorb.  If you don't Absorb every day, then that efficiency might be higher.

You sure you mean A-H efficiency and not W-H efficiency, Vic ?   Would love to hear more.
boB

Hi boB,

YES,   II DID intend to state,  specifically,  Ah Efficiencies in the range of 85-ish percent for broken-in,  but young batteries.  We pay attention to Ah removed from batteries,   so Ah  Efficiency is what counts here.   But,  in re-reading my post above,   only made a glancing reference to Ah Efficiency.

Again,   I claim to be no expert on this.   Will look for some references to Ah Efficiency statements from battery manufacturers.

More later,   73,   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!!