Changing bank size in Classic 150

2twisty

Since I am temporarily disconnecting half my batteries, I need to tell the Classic that my battery bank's size is now 200Ah instead of 400.

How do I change this setting from the MNGP?  I've looked in every menu and even looked at the menu map posted online.  I can't seem to find that setting.

I need this answer immediately, since I have to change it and then leave the house on a personal emergency.

2twisty

I found it.  Totally obtuse place.

You have to press the status button until you get to the WbJr screen.  Then you press the right top soft key for setup and you can change the value there.

Totally NOT in any of the SETUP menus.  Dumb.

Anyway, I found it.

Vic

Hi ..twisty,

Yea,   the more that you use the menus in any product,   the more familiar they do become.

The bank size only really matters for the SOC,   Remaining Ah,  etc.

While SOC and Remaining Ah can be a very rough indication of these values,   it is often a good idea to just pay no real attention to them,   on any Battery Monitoring device,    as,   they can be very misleading.

Since you have Flooded batteries,   measuring SGs is such a good indicator of SOC,   which will directly indicate the remaining AH (after temperature compensation,   if needed),   why not just use the measured values.

Think that Estragon mentioned the use of a Pilot Cell (or several)   as a quick measured SG indicator for each string.

Just be certain to RINSE your good glass Hydrometer  three.    or four times after your SG measuring session,  this will keep the measurements accurate.   If the battery temperature is far from the reference temperature (77 - 80 F),   then compensate the SG readings.

FWIW,   Good Luck !!   Vic

2twisty

Yeah, apparently I put too much trust in the WBJr.  It faithfully told me I was getting to float 3-4 days a week.  It reported that SOC was 100%.  

What it didn't tell me was that C/20 is WAY too low.  I was only solar charging a 400Ah bank at 20A.  I guess 2H absorb wasn't enough and it was ending before end amps finished. As far as the data was telling me, it was all good.  Of course, I wasn't monitoring SG like I should.  Tracking 48 cells can be a PITA...  Lesson learned.

I wonder why I got so "snookered" by the data I was seeing?  Wishful thinking?  Rose colored glasses?  Aside from tracking SG directly, what else should I give trust to, and what should I be skeptical about in terms of the data that my Classic/WBJr and my Outback provide?

Vic

2twisty,

For Lead Acid batteries,  there is really no battery monitoring device that can accurately tell you SOC,   in varying conditions,  unless it,   somehow actually measures SG of each cell,   or something.

Most Battery Monitors count Ah into and out of batteries,   but the Rate of discharge and charge, relative Absorption voltage,  battery temperatures, frequency,  voltage and adequacy of EQ,  battery age,   and on,   and on.   There are just too many variables that are not accounted for.

The Classic resets SOC to 100% upon the Classic making its own transition to Float (and NOT when one Forces Float).   SO,  100% SOC depends completely upon just how the WBjr parameters are set,   the relative Absorption voltage,   Absorb time,  EA value (relative to where your battery would like it to be set)  etc.

SO,  you are correct,   that measuring SGs is the Gold Standard of SOC.   You could identify one or two Pilot Cells in each string,  and use the as a quick read on approximate SG of the battery bank.

BTW,  am not familiar with the model of Hydrometer that you mentioned that you were using,   recently,   but it sounds like it should be fine.   Just remember that the Hydrometer should be rinsed three of four times with distilled water to help keep it accurate.   And would not wait for more than an hour or two to rinse it ...   but that is just me,  tasting the expelled rinse water after the second and third rinse to make certain that it is clean ...   yea,   nutso.

Wish your wife and you well with her medical situation --  GOOD LUCK.   Vic

westbranch

Winter is a time of getting as much ABSORB as you can from  solar, so if you have a gen set, start it up once a week and let the solar FINISH off the Absorb if it can....  use the WBjr to set EA ....I set it as low as I can....01A  ...... I know |I have to put up more PV !!  just waiting for a wood shed to pop up...

2twisty

I'm still trying to revive the older string.  After the newer string easily hit float today, I swapped them and let the old string get some charging time.  Hopefully, they will recover.  Strangely enough, after reducing my overnight loads, the fact that i only have half as many batteries isn't as crippling as I had feared.

westbranch

Yup, it doesn't take much of a constant load to add up to 1000W overnight....Our Net connection can do that all on its lonesome.. without any 'use' at all...

mcgivor

2twisty said:

I'm still trying to revive the older string.  After the newer string easily hit float today, I swapped them and let the old string get some charging time.  Hopefully, they will recover.  Strangely enough, after reducing my overnight loads, the fact that i only have half as many batteries isn't as crippling as I had feared.

Probably the bad string was dragging the good one down, being the weaker link, so to speak, this is the reason you'll hear so often, use batteries all of the same type and age, the good ones suffer on behalf of the bad.

BB.

5% (C/20) rate of charge can work--Generally for weekend and seasonal (non-winter) systems that mostly charge during the day and discharge at night.

The other issue is getting high enough voltage and charging current for that Absorb time. And EQ, you want high enough voltage (15-16 volts roughly, for a 12 volt bank) to get 2.5% to 5% rate of charge for EQ.

Many vendors recommend 10% rate of charge for their storage batteries... 5% is minimum recommended by a couple of vendors (all usually based on the 20 Hour battery capacity numbers).

-Bill

jonr

Worth repeating - insufficient absorb time can kill batteries.  And with low charge rates (like  < 10%), it can take a long time.

Dave Angelini

And insufficient charge source that pulls the absorb voltage below the set-point from clouds and loads. Some controllers are fooled by excess time in absorb and will go to float. This of course is why one needs to at least look at a pilot cell SG to see the state of charge when transitioning to float.

Having the correct rate of charge that is recommended is not enough, one has to have the sun on a regular basis or add more solar.

boB

A battery bank can be recharged even it doesn't go through an Absorb cycle BUT it must be done once in a while to help prevent sulphation of course.  As long as it was actually getting to Float every few days, that should normally be OK. But batteries can have bad cells too.
I like to look at battery temperature while charging to find the bad ones.

The amp-hours re-charged must be at least the amp-hours discharged plus the amp-hour inefficiency.  This assumes  the batteries are in OK shape.   You can do a load test on the batteries with the WB Jr. (assuming it IS reading correctly) by giving the batteries a GOOD long Absorb charge, then load them down while watching the voltage drop or watching the SG until drained OR half drained or some point you know the SOC%.  Have to pick a good C/x value that agrees with the manufacturers' specs most likely.

You're not going to get much more accurate than the WB Jr. as far as amp-hours in and out as long as it or something else is not broken.

Sorry about the menus.  Since the WB Jr. is shown in another "status" menu, it was appropriate to put the sub-menus within its menu rather than a non-related menu (we thought), otherwise it would have to be in two places and adding menus is not a simple task.

boB

westbranch

this is why I prefer using the 'Local App' for making changes... makes life very simple, and you don't have to keep pressing buttons ad infinitum,  my rotator cuff tells me so

Since the WB Jr. is shown in another "status" menu, it was appropriate to put the sub-menus within its menu rather than a non-related menu (we thought), otherwise it would have to be in two places and adding menus is not a simple task