CC does not go into absorb mode

elesaver

I'm having some difficulty identifying a problem with returning my forklift batteries to full Ah.  Instead of 930+ Ah after a day's charging, they are doing well to return to 850+ Ah.  The SG is a bit low...should be 1.285 but cells range from 1.240-1.280 so they are not getting to full charge.  Bulk is set at 27.8, float at 26.5, EQ at 31.2.  I have done 2 EQ cycles but they did not complete in one day, taking two days instead.  The battery voltage remains high so that's why this is going to float so quickly with no absorb cycle.  Ending amps is set at 27.8 per the battery manufacturer.

Currently I have no load on the batteries to see if I can bring the Ah and SG up but I'm not sure which settings to change.  I tried increasing the bulk rate and the float rate but that didn't help.  On the menu for charge, then going to charge time, and then timer view, absorb cycle has not been activated.  It is set a 4 hours but it has not absorbed at all.  The float time (for today) is almost 6 hours.

I hope my equipment list shows at the bottom.  This is a new set up since I visited last so maybe it doesn't.  All suggestions are welcome.  

westbranch

What are the settings from the Manufacturer? I would have expected a Bulk/absorb to be at or above 28.8

I suspect you need to increase the ABSORB Voltage , that is the usual cure recommended for others having a similar problem.....

Anawa

elesaver, I have experienced the same thing. Look for my prior post on this same subject. The forum contributors have been helpful in diagnosing what I needed to do. Good info on the batteries in that thread.

For me and as recommended, I re-set my end-amps to 0 in in the CC order to get into a monitorable absorb cycle and bumped my absorb voltage to a high of 60.8. I've monitored the cycle now for a few months and currently things "seem" stable with my end-amps at just 7 and the abs voltage at 60.00. I was planning a post on the forum for feedback on my settings, maybe the time is right. I'm beginning to think that the charging/discharging environment and equipment used with off-gird forklift batteries require different settings that the warehouse environment.

I pay close attention the the overall operating system, as well as daily SG reading, and continue to be mystified with the characteristics of the "fork-lifts" as compared to what other off-girders say about their "typical" RE batteries. My forklifts seem to behave somewhat differently: needs higher voltage, lower end-amps, rapid drop in the charging current-to-voltage ratio, etc.

An interesting characteristic of my batteries is that to reach 1.285 SG, the abs voltage must be very high (like almost the manufacturers EQ recommendations). Another fact for my batteries is that I am not needing to add excessive water with the high voltages although I get a lot of bubbling. The battery temp is never high.

Just throwing in my $.02, for what's it worth.....

Paul
in Georgia

elesaver

Thank you for your insight, Paul and Westbrook.  I'll have to check again but I don't think the Midnite Classic has a voltage adjustment for the absorb cycle.  It has bulk, float, EQ.  The time in absorb is adjustable.  If it's there, I've never adjusted.

The settings I am using are the ones that the manufacturer suggested.  After a call today, it is suggested to up the EQ to 31.7.  I may try that tomorrow.

I installed these batteries in September and they were functioning as I expected...I'd see the amps "replaced" during the following day, etc.  It has been about a month and I've "tinkered" around with the settings but have not been able to return to the specs that I should be seeing.  I called the manufacturer today and they suggested I check with Midnite Solar.  This was suggested because when I began with these batteries, absorb cycle was working as it should.  I thought I'd check here to see if anyone had ideas.

Paul, I had looked for answers by searching and didn't find anything.  I'll look again to read the earlier post you referenced.

Thanks again.  I'll keep working on it.

vtmaps

elesaver said:

 I'll have to check again but I don't think the Midnite Classic has a voltage adjustment for the absorb cycle. 

It is most certainly adjustable.  --vtMaps

edit:  do you have a midnite whizBang Jr?

vtmaps

elesaver said:

The settings I am using are the ones that the manufacturer suggested.

When a forklift battery (in a forklift) is charged, there are no loads on the battery and no charging sources other than the battery charger.  The charger is powered by the grid.... no clouds.  Therefore, the battery can be charged by a completely different protocol than the standard bulk-absorb-float used in the Renewable Energy business.  Many of the forklift charging protocols use the terms absorb and bulk differently than we use the terms in the RE business. 

read about "IUoU" and "IUIa".  These are din naming conventions for popular charging protocols.  IUoU is the standard RE charging protocol. 

--vtMaps

Anawa

Thanks vt. More clarification is always a good thing. 
Paul

westbranch

and when charging from the grid, Amps and Volts are not  limited so both are at max to start, limited by only the batteries resistance, while the PV charge starts with the max amps it can produce, at any given time point, and as the sun rises and the charge progresses the volts provided rise to the Absorb limit, once that Absorb set point is reached and held, the volts are held steady and Amps will start to decrease till  the Time limit or End Amps limit is reached...

hth

zoneblue

In other words there is no bulk setting. During bulk the voltage is dictated by the battery.  The key to happiness there is to do some test cycles. Turn off emp amps and absorb time, and just let it absorb until when the SGs come up... thats your end amps setting. Add half an amp for the noise floor.

elesaver

Thanks for the additional info.  I'll keep working on it.

"Turn off emp amps and absorb time, and just let it absorb until when the SGs come up... thats your end amps setting. Add half an amp for the noise floor."

I want to try this, zoneblue.  How do you measure the amps to know the end amps setting?  Thanks for the help.

Dave Angelini

I think he would tell you how by measuring SG with a hydrometer.  The end amps should be very close to 2% of the 20 hour AH rate for your battery if it is a battery in good health.  This may not happen the first time you do this but should in the next few weeks if all is well.

zoneblue

Either with a DC clampmeter, or if you have the WBJr using the "system amps" reading on the classic. As the WBJr is quite sensitive to get the cleanest results turn off any noisy loads while you do this. As Dave said 2% is a good rule of thumb, but it will vary for each bank.

Anawa

Any comments from the off-grid battery experts on the long term effects of my forklift battery charge settings: 60.0 abs voltage, 7 end-amps, water usage (infrequent refills), and battery temp?

Currently, I max-out the SG at 1.285 (100%) every 10 days or so, reach SG of at least 1.270 (90%) at least 2 times a week, and read SG of 1.275+ (93-95%) maybe 2 times a week. Rest of the week, the lowest SG reading at dusk is about 1.265 (86%). SG readings variance between my "hot" and "coolest" cells is about 0.006. This variance does not change much after an EQ, maybe closes to about 0.003. 

One more bit of information, the only way I have been able to reach the SG of 1.285 (100%) is with an EQ charge set at 63.0. The batteries do gas a lot, but the temp is not excessive. BTW, the battery manufacturer (GB Industrial) recommends that an EQ charge be made every 5th charge cycle.
 
Comments on this would be appreciated.

Paul
in Georgia

Vic

Couple  of comments;

Deep-Cycle batteries DO need to be cycled,  at least on occasion.

New Deep Cycle batteries need to be cycled a number of times ( 20 - 50 cycles) to about 60% SOC,  or even a bit lower,  and recharged to at  least 90% SOC soon after this discharge.

The initial cycles help to build ultimate Capacity,  and help finish forming the plates.   These cycles generally help the battery to settle in,  and become more stable and predictable.

IMO,   Vic

Vic

elesaver,

What version of FirmWare you running in the Classic?

I would not worry so much about AH returned to the battery at this point.   Would also suggest a Vabs of about 30 V,  temperature-compensated for as many hours as it takes to get the temperature-compensated SG readings where they need to be,  on average.

Yes,  your original EQ voltage seemed low.  Especially on an RE charged system,  a higher voltage  --  31-ish volts should be OK, to try to get as much EQing done in one day.

Make certain that your charge and EQ voltages are temp compensated.

AND,  make certain that the Classic is not Limiting the charge voltage range to its factory default settings,  which are much too narrow for Flooded batteries,  especially Lift Truck batteries.

Also,  as you know,  battery voltage readings should be temperature compensated,  when monitoring battery voltage.  Most of the Traction batteries use a compensation of --5mV per degree C.  So,  --60mV per C for a 24 V battery  --  this can have a large effect on battery voltage readings.

And,  as you know,   temperature has an effect on battery Capacity.

It has been asked before,   do you have the WBjr installed on the Classic?

More Later,   Good Luck,  Vic

elesaver

Thanks, Vic.  I'm still working on this.  Yes, I have a Whizbang, jr.  The batteries are not temperature compensated.  The temp. sensor didn't fit into the battery case with these cells.  The manu. suggested that I superglue the sensor to one of the terminals but I have not done that.  I'll change those readings today.

Yesterday, I raised the EQ to 31.7 and did an EQ cycle.  I am going to check the SG today...by the time I could've done it yesterday, it was too dark.  The cycle did complete, however.

We're going to be in the snow/ice beginning Friday early morning through Saturday.  I had hoped to be prepared for this!  Power outages could happen if the ice accumulation becomes what they say it might.  At least I have today to try to rectify.

Thanks again.  I'll report later.

elesaver

Following up on progress with getting settings on CC corrected.  Yesterday, we had beautiful sun for most of the day.  This was a perfect opportunity for monitoring changes in absorb time, voltage and ending amps.  I lowered the EA from 27.8 (suggested by manufacturer) to10.0.  I picked the 10 in reference to usual settings between 1-2%.  I increased the absorb voltage to 32.0 and the time to 4.5 hours.  Yes, this was high but I wanted to get these batteries back up to snuff as well as observe.  Worked like a charm!  The SG was back up to 1.285 and the batteries did not seem to get hot or actually, they weren't even warm to the touch.  There was some gassing, of course, but the water levels were good at the end.  I will check that today.  So, I think I'm on the way to figuring this out.  I don't have a clamp meter to know the actual EA number but I'll figure it out.  Thanks to everyone who has contributed.

I have encountered something else that I question in the CC that I will post as a new thread.  Thanks again!

Dave Angelini

The output amps from the charge controller in Absorb are the end amps if all the other AC or DC loads are turned off.

elesaver

Thanks, Dave.  I'm beginning to understand.

Hate to be dense here, but I must face the facts. About some things, I am dense.  This is one of them. 

 Currently I have no AC or DC loads.  I have seen the voltage on the CC screen  as well as the amps.  Are you telling me to look for the amperage at the time the CC completes the absorb cycle?  If the absorb cycle is based on time, it would stop absorbing when the time expires, I would think.  That would not necessarily mean that EA had been reached but only that the time had been satisfied.

The biggest problem here is I don't think I get it.  Please help correct my thinking which is this:  Values are put into the CC to control the charge to the batteries.  The absorb voltage is triggered when the bulk mppt completes and during the absorb cycle, the battery charge is continued until the EA value is reached or the absorb time that has been programmed is completed.  Is this right?

If this understanding, then, is correct, once I get these batteries back with full Ah, etc., I can watch to see when bulk mppt goes to absorb and then watch for the displayed amps when float is initiated.  That amperage is the EA.   Perhaps there's an easier way?  Clamp meter, I suppose.

Vic

elesaver said:

Thanks, Dave.  I'm beginning to understand.

Hate to be dense here, but I must face the facts. About some things, I am dense.  This is one of them. 

 Currently I have no AC or DC loads.  I have seen the voltage on the CC screen  as well as the amps.  Are you telling me to look for the amperage at the time the CC completes the absorb cycle?  If the absorb cycle is based on time, it would stop absorbing when the time expires, I would think.  That would not necessarily mean that EA had been reached but only that the time had been satisfied.

The biggest problem here is I don't think I get it.  Please help correct my thinking which is this:  Values are put into the CC to control the charge to the batteries.  The absorb voltage is triggered when the bulk mppt completes and during the absorb cycle, the battery charge is continued until the EA value is reached or the absorb time that has been programmed is completed.  Is this right?

If this understanding, then, is correct, once I get these batteries back with full Ah, etc., I can watch to see when bulk mppt goes to absorb and then watch for the displayed amps when float is initiated.  That amperage is the EA.   Perhaps there's an easier way?  Clamp meter, I suppose.

elesaver,

You are correct about what ends Absorb  --  it is an OR function,  either the Absorb time set,  OR,  the EA ends Absorb,  which ever one occurs first.

AND,  with NO loads on the battery (DC to the Inverter is switched OFF),  then the Output Current reading from the Classic IS the charging current into the battery.

You did say that you "have"  the WBjr.   Does this mean that the WB IS installed onto a Shunt,  and has been connected to the Classic,  and is set up and working?

The WB has very a accurate readout and tally of Amps and AH to/from the battery.

Also in that Thread,  you mentioned that you are not presently using the Remote Temperature Sensor/s.   Even it you just tape the sensor onto the top of one of te cells near the center of the bank,  this should be better than nothing.

Make sure that you Tempertature-Compensate Veq,  and look at the Limits menu in the Classic to make sure that the Voltage range is appropriate for Flooded batteries  --  the Default compensated voltage range is far too narrow for Flooded batteries.

QUESTION:

What is the Firmware version that the Classic is running?

Thanks,   Vic

elesaver

Yes, Vic, the WBjr is installed into a shunt and is working.  I had turned off the temp compensation so I will try to attach the temp sensor to one of the cells and turn that back on.  I'll check back into the comments to make certain of the value to put in there.  I think someone said it should be -60mV?  As far as the firmware...the notes I have from the installation say it is 1070.  I checked "the manual" (such as it is) to see where to find that at this time to re-confirm but after going through all the screens, I don't see anything.  The voltage range in the limits is min: 25V and max: 45V.  Actually, I don't know how these affect the charging.  Sad, yes, I know...but true.

Vic

Hi elesaver,

Thanks for the added information.

The Temperature Compensation value for most Flooded Traction batteries is --5mV.   This the value of compensation per cell per degree change in the battery temperature.  The total compensation for your 12-cell battery IS 60 MV per degree C,  but this is not what you will set for the Classic to use ...

The Classic will calculate the total compensation value for your 12-cell battery,  so you should enter --5MV into the Classic for the comp value,  UNLESS you have information to the contrary from the battery manufacturer.

To see the Firmware version for the Classic and the MNGP,  you press the right small button (the one that takes you to the Main Status screen six or seven times,  until you see the screen that displays these two FW version numbers.

If the Classic is several years old,  and you have never Updated the FW,  you probably should do this,  as there have been a number of improvements made,  most probably including support for the WBjr.

If you are not yet a member of the MidNite Forum,  you should probably join,  as there is a lot of support for the MidNite products,  there:

http://www.midniteforum.com/

And,  if this battery bank is fairly new,  and has not been cycled very deeply,  or often,   it might be a good idea to do so,  as,  Deep Cycle batteries really DO need to be cycled,  initially,  to help "Finish" forming the plates,  and on occasion after that for general battery health.

More Later,   Thanks,   Vic

zoneblue

Yep now is the time to get this humming right.
1. temp comp very important
2. if the firmware is 1070 then WBJr wont work. Upgrade to 2079, which is the current release and is very stable. (Be sure to do the full hardware reset to factory mentioned in the instructions, as this is a large software jump).
3. You need to configure  WBJr correctly. (enable WB under AUX2, AND tell EA to use WBJr). Also check that your purple wire is conneced and the shunt is oriented correctly.
4. Set the absorb and float times to the best figures you have.
5. Then do your test absorb or 2 with abs time temporaily set to 12h, and EA temp set to 0. When the SG comes up, force float manually.Then set your abs time and EA to the correct values. Remember that with EA the abs time is a fail safe / backup to EA. So pick a time that is just a bit more than your longest usual time. The EA value itself weve talked about above.

elesaver

Got the firmware info:  MNGP  1821; Classic 1849

I had wanted to upgrade the firmware earlier but I don't have a laptop and I don't have wireless.   I had even bought a router to try to have that capability but this computer is so old that it doesn't support wireless!  If there's a way to do it with my equipment, I'd love to try.

The WBjr is working under AUX2.  Yes, the battery bank is new (Sept 2015) and has not been cycled too deeply so I'll work on that.  I'm well satisfied with the bank but I didn't want to discharge it beyond 25%.  Apparently, my settings were correct to the point that things were working but it was slowing losing capacity.  Because I understand better now, I think I can get things back on track.

Again, I thank all of you for your help and info.  I hope you never tire of being such a great resource for people who don't have any other way of learning the "art of solar power."

Yes, I did join the midnite forum but I forgot my password...why would I write that down!  Anyway, I had gone there a time or two to try to "guess" but could never got it.  There doesn't seem to be a link for "forgot password."  If there is one, please point it out to me.

Thanks again.  I am so grateful for all the help.

elesaver

Oh, my!  I just went to the midnite forum to guess at my password and it worked!  it's a miracle.  I'll record it this time.  

Vic

Hi elesaver,

Am still running 1821/1849 on all Classics,  here.   Have been thinking of updating to the most current rev,  soon.

You might be better off NOT trying to update the Firmware at this point.  Perhaps you could borrow a Laptop.

The newish Windows 10 Update software has gotten much better,  as I read it,  but one needs to make certain that the Classic does not get "bricked"  when trying to do the update,  so might be best to wait.  The FW that you are using now should be fine.

Good that you have the WBjr running.  If you press the left small button on the MNGP,  you should get to the screen that displays the actual battery charge current,  if the WBjr is fully set up.  You will know if the WB is communicating with the Classic,  if you see the green LED on the WB circuit board (attached to the Shunt) flash quickly about once every five seconds.

When your battery is fully-charged,  putting some loads on the inverter,  like an electric heater/s or similar,  you could try to cycle the battery down to aroungd 60% SOC,  or so.   If you did this early on what should be a sunny day,  you could possibly mostly recharge your battery in one day of good sun,  depending on where you are located.   Believe that this system is a Backup to Grid power (IIRC),  so,  you might need the grid for the last part of the recharge.

Once the battery becomes conditioned by cycling,  you probably would need to change the Absorb voltage,  and your Shunt EA settings,  and so on.

Good that you are a member of the MN Forum ...  had felt that if you were going to update the FW for the first time,  having the support of the community on the Forum could be a very good thing  --  glad that you remembered the password,  that is always a  good thing.

Have Fun with the new system,  and please let us know how you are doing.   Thanks,     Vic

elesaver

Yes, Vic, I think it would be unwise to update the firmware at this time.  It appears there may be some problems, so since this is working well, no need to update now.  Yes, I know to look for the intermittent light to know the WBjr is working and I have watched the battery current, amps, etc.  My biggest hesitation has been to take the batteries down too far but now I am understanding that here at the beginning, it may be a good thing to get them "settled."  Yes, this is a back up system.  I don't believe I have enough panels to create enough input.  I guess that, too, is because I didn't want to have too great DoD. 

I'll cycle a bit after the weather improves.  I'm in the SE so quite a bit of sun on many days.  Now that I have the added info from this last "teachable moment," I will be able to do a better job of keeping the settings to the point that the job of recharging can get done properly.  I do watch the system and the numbers all the time, enjoying seeing how wonderful sunlight is and to marvel at the technology that has been developed to harness a smidgen of the sun's power. 

Thanks for all your info and patience.  Thanks to everyone who takes time to help.