Ensuring I am doing the right thing

Rngr275

My system has been up and running for a little over a month now and everything is working great (knock...knock!). I was reading the thread about knowing if your batteries are fully charged and wanted to make sure things are set up ok here and let you guys make sure I'm not headed for trouble.
My new Trojan L16RE's have not had an equalization done on them. My installer told me that they were fully charged at the time of installation and that Trojan suggested working them out for a month or so before doing an equalization on them (but not to go below 50%SOC). I have not checked the SG but will as soon as my hydrometer shows up from NAWS.
Since the system has been up I have not gone below %90 SOC with the average daily AH out of the batteries ~45-60AH. Charger set points (2 Classic 200's) are EQ=61v, Absorb=58.4v, and Float=54v, the charge times are Absorb min time=30minutes, Absorb max time 2hr, EQ time=1hr.
I notice Trojan's site calls for Daily(what ever that is Absorb?)=59.2v, FLoat=52.8, and EQ=62v.... so my set up is pretty close. With 4Kw of PV and pretty sunny days this last month the batteries are at float just about everyday.

It just feels like after a month I should be checking them more closely, doing an EQ... or something. I have checked the water level and all looks good there. I just don't want to be another of those "Ruined" their first set of batteries. I check my FlexnetDC all the time.

Am I just being paranoid or do you have suggestions of things I can and should do or check?

Cariboocoot

Re: Ensuring I am doing the right thing

It would have been nice if you could have checked the SG when you first got the batteries and the dealer said they were "fully charged". If you tell any type of battery monitor they are fully charged when they aren't it will be wrong from then on.

Yes the Trojan specs are Absorb 59.2, et cetera. They like higher than 'typical' Voltages.

They also recommend you don't equalize unless there is a difference of 0.010 or more between any two cells.

BTW you can program your Flexnet to do End Amps on the Absorb. You should set the Absorb time to maximum some day, watch the current (with no loads other than the inverter preferably) and see when it gets down to about 2% of battery capacity (that number plus constant loads would be your End Amps). The time would be the max you want on the Absorb time limit.

Otherwise I wouldn't worry about anything until you get your hydrometer and measure the actual SG.

vtmaps

Re: Ensuring I am doing the right thing

Rngr275 wrote: »

I have not checked the SG but will as soon as my hydrometer shows up from NAWS.
<snip>
Am I just being paranoid or do you have suggestions of things I can and should do or check?

Check that SG in each cell and write it down. Battery monitors need to be calibrated to the battery. If you were at less than 100% SOC when you hooked up the flexnet DC, the flexnet will call that level 100%. In that case you might be hovering around 80 or 90% SOC for the past month. Even if you were at 100% when you started, the monitor and batteries can drift apart. This occurs, in part, because the criteria that you use to tell the monitor when the battery is fully charged (end amps, time, amphours, or whatever) may not be exactly correct.

One of the great advantages of flooded cells is that the SG can be readily checked. Search this forum for 'hydrometer' and you will find a few tips for getting accurate readings.

--vtMaps

Photowhit

Re: Ensuring I am doing the right thing

I'm a big fan of equalizing, but Trojan specifically does NOT recomend equalizing most if not all of their batteries unless you find a large inbalance between the cells!

OK I wrote this then went to find the PDF to back it up and the first one I found, suggests equalizing every 30 cycles in automated systems;

http://www.trojanbatteryre.com/pdf/TRJN0169_UsersGuide.pdf

The second link has more of what I've found in the past, "...Trojan recommends equalizing only when batteries have low specific gravity, below
1.250 or wide ranging specific gravity, 0.030, after fully charging a battery."

http://www.trojanbatteryre.com/pdf/TRJN0109_TRJNUsersGuide0310Lr.pdf

Neither link describes the specific battery, though the first is for 'industrial batteries'

Rngr275

Re: Ensuring I am doing the right thing

The user manual that came with the batteries said to only equalize the batteries when there is a range of SG from cell to cell (0.039). It also says that the batteries will not reach their full potential until they have been excersized for 20-30 cycles. I guess my plan is to wait until my hydrometer shows up, measure the SG on all the cells so I have my baseline and make sure that all the input values to the FNDC are correct.

Think I should bump up the absorb to the 59.2 they reccomend or is the 58.4v OK?

jeffkruse

Re: Ensuring I am doing the right thing

1/2 an hour to 2 hours seems really short for absorb time...

Vic

Re: Ensuring I am doing the right thing

Hi Rngr..

Please use the settings recommended by Trojan, at least until you do get the Hydrometer. I do not want to pick, but a few tenths of a volt does make a difference, so, IMHO, your settings are not really that close to the recommendation.

As noted above, a Batt Mon can be very misleading. It is a good thing to look at, but MEASURED SG is really the Gold Standard of battery State Of Charge. Read about using the Hydrometer to make accurate measurements. RInse the Hydro several times in Distilled water after each measuring session, to help the Hydro perform well in the future.

Believe that FNDC EA might only work with OB FM series CCs, but EA is a good way, in general to end A.sorb. YMMV Good Luck, Vic

mtdoc

Re: Ensuring I am doing the right thing

Vic is correct that the FNDC cannot control the charge cycles of your Classic CCs - i.e cannot use end amps to directly end absorb on the Classics. It can however track SOC accurately if calibrated correctly. If you haven't seen THIS outback tech note, it's worth looking at to be sure your FNDC is set up correctly.

The Classics can use their own measured end amps (less accurate than the FNDC's shunt measured EAs) to terminate absorb (I believe this is working with their latest firmware). With the FNDC you can determine the best end amp setting for the Classics by watching the return amps taper off to approach steady state at the end of absorb. This is easier to do with software such as Wattplot, Greenmonitor, etc. since you can simply look at logged data on a graph and not need to watch the Mate screen.

Rngr275

Re: Ensuring I am doing the right thing

Thanks for the Link to the Outback tech paper. Very helpful!
I noticed some differences and will be taking care of them. The biggest one was the "Return Amps" which was set @ 5Amps but based on Trojans 1-3% of the total amp hours of the battery bank (which is 14.8amps for my 740AH bank using 2%) though I don't fully understand what this is exactly...can anyone explain the significance.
I will probably bump up the absorption voltage to Trojans recommended 59.2. do you think the float should be lowered to 52.8 instead of the 54 currently being used? And so I can continue to learn why or why shouldn't I change it.
I'm expecting my hydrometer in a day or 2.

Vic

Re: Ensuring I am doing the right thing

Hi Rngr.,

YES, please follow the exact charger settings recommended by the manufacturer -- Trojan. They should know, they made those batteries. The high setting that you have for Float is considerably higher than they recommend. If you were to spend hours in Float, this high voltage setting could cause some additional positive plate corrosion, which damages the battery bank over an extended period of time. Also, the EQ being set at 61 instead of 62 can make a large difference. Normally, one sets the Float volatge such that the battery just (barely) maintains SG readings when in Float.

Have not looked, but these settings may well be the Default settings from the Classic CCs. Every battery manufacturer has a bit different requirement, and they generally know what is best, especially for Float and EQ voltage settings. The CC manufacturers genearlly make defaults a rough average of the mfg recommendations.

The Absorption voltage can be a bit different, depending on the time of year, the amount of recharge current available, and the Depth Of Discharge. These A.sorb paramaters need a bit of adjustment depending on your exact conditions.

Return Amps is the same as End Amps. This is the charge current that is going into the batteries. The current that is being delivered by the CC toward the batteries, is usually not all going into the battery as charge current. The inverters, and any loads on them cause the CC to show higher currents than actual batt current. So, an EA setting in the CC may need to be set a bit higher, depending on the amount of the current drawn by and from the Inverters.

Some have said that the BMK is not a true Battery Monitor, but I do not know for sure. A shunt that is placed in the negative lead of the battery can tell the true current going into the battery. I am unsure that the BMK has this shunt. And so on ... Vic

mtdoc

Re: Ensuring I am doing the right thing

Vic wrote: »

Some have said that the BMK is not a true Battery Monitor, but I do not know for sure. A shunt that is placed in the negative lead of the battery can tell the true current going into the battery. I am unsure that the BMK has this shunt. And so on ... Vic

Hi VIc,

What is a BMK?

Vic

Re: Ensuring I am doing the right thing

Hi mtdoc,

OOOPPPPppsssss, You caught me. Right. The OP mentions the FNDC and OB inverters. Sorry.

The FNDC is a REAL Bat Mon, and has the important Shunt in the neg lead of the batts, correct!

As noted above, any Bat Mon must be calibrated, and then recalibrated. Thankfully, Rngr has FLA batteries and can actually measure SGs when the Hydro arrives. And if the bat mon is calibrated now, it will drift as the bank is cycled. So it is probably a good idea to watch this calibration several times in the first month or two of this new bank's life. Some folks seem to rely on a bat mon as the absolute, accurate SOC readout, and can run into trouble after a number of months. So, please consider the Hydrometer to the the truth about SOC. Be certain to rinse the Hydrometer several times after each measuring session, using distilled water. This is big help in keeping those pesky air bubbles from sticking to the guts of the hydro, and causing false readings. Thanks mtdoc for catching my mistake. Vic

mtdoc

Re: Ensuring I am doing the right thing

Vic wrote: »

Hi mtdoc,

OOOPPPPppsssss, You caught me. Right. The OP mentions the FNDC and OB inverters. Sorry.

The FNDC is a REAL Bat Mon, and has the important Shunt in the neg lead of the batts, correct!

Ok, No biggie. I was just confused since I don't know what a BMK is. Is that another type or brand of battery monitor?

Vic

Re: Ensuring I am doing the right thing

Correction mtdoc, I was confused, too many Threads, and not enough re-reading on my part.

Believe that there is a Magnum BMK, or similar abbreviation, that may tally the amount of battery power that the inverter uses ... ??? Or something like that. If that is the case, it could help decode AH taken from the batts. Am too lazy to read the manuals to see.
Anyway, thanks for catching my error.
Your new system looks very nice, and, having lived in Spokane, and SeaWA, believe that your location is probably the sweet spot for weather in the PNW (if I have your location pegged correctly).

Have fun, and enjoy the Fall weather. Vic

mtdoc

Re: Ensuring I am doing the right thing

Thanks Vic. Yeah - we like it here in the "rain shadow" of the Olympics - less rain and more sun than Seattle but not as hot as Eastern WA (I hate heat!). Still more sunshine would be nice - it's raining today.:roll:

I appreciate your expertise here and on the other boards. I'm always trying to learn more. Now I know what BMK stands for!

Rngr275

Re: Ensuring I am doing the right thing

I hope somebody checks back into this thread. I received my new hydrometer yesterday and was all ready to check all the batteries today at the end of the day charging. It was a real mixed day for charging, some sun lots of clouds The classic 200's ended up in float by around 3PM but the FNDC only got to 98% which is relative to where it thinks it is since there has never been an SG reading take to verify 100% Charge is 100%. Anyway I really wanted to see a good long day of float before I checked the batteries but I couldn't wait. I figured that the batteries were in float for a couple hours and the FNDC thinks the battery bank is at `98%. So I check 1 cell on 4 of the 16 batteries To try out the hydrometer and to just get a feel for where the batteries were. To my surprise the the first battery tested gave a reading of 1.250 and when adjusted for temperature the SG was 1.244. All of the other sells gave the same readings. A little quick math and it appears that my battery bank at that time was at ~83-85% SOC. The FNDC thinks the bank is at 98%. Over the past month the lowest SOC I have gone to was ~90% on the FNDC which in all actuality was probably like 70-75% SOC.
I am a little perturbed with my installer for assuming the batteries were at 100% when he fired up the FNDC but he did say that he wanted to have the batteries go through a month of cycles to get the batteries "up to full potential" per Trojans recommendation.

But I think it is time to get these batteries up to 100% and reset the FNDC once the batteries are at 100% so that it is monitoring and giving me information from the correct baseline. SO with that in mind how should I proceed?

Tomorrow looks like a mostly sunny day, so do I let the charger go through bulk then go to EQ or let it go into absorb then EQ. Trojan told me to give them a good 3hrs then start checking SG and check SG every 30min to and hour after that till there is no more change in SG. Suggestions?

The for you FNDC owners how do I reset the FNDC so that it knows that it is NOW at 100% and we can start some real battery monitoring?

Thanks all.

Cariboocoot

Re: Ensuring I am doing the right thing

They should have given you the documentation for all equipment installed, including the FNDC User's Guide http://www.outbackpower.com/pdf/manuals/flexnet_dc.pdf
You need a MATE or MATE II to program it (see page 13). If they left that out of the system you'll have to get one, preferably with a HUB to tie everything together.

BB.

Re: Ensuring I am doing the right thing

I don't know about the FNDC battery monitor--But the way they usually work is you program them for something like >14.5 volts for >3 hours, then the unit resets back to 100%.

It is sort of like measuring the fuel in your gas tank by monitoring the fuel going in and out the fuel line. Short term, the accuracy is near 100%, but over time, the fuel reading flowing out does not quite square with the fuel flow going back into the tank--So the assumed fuel level starts to drift from the actual.

In the case of the battery monitor, the automatic reset is usually based on having XX charging voltage for YY time--Then the battery is assumed to be 100%.

If the meter is never reseting, then either the voltage/time numbers are not being matched (you are not charging enough), or the numbers are too high for your application (i.e., flooded cell voltages on a AGM type battery bank).

The FNDC seems to use a termination current as full (i.e., if battery is at 14.5+ volts, and the charging current is ~2% of rated AH capacity for over 1 minute, then the battery is full).... Note that the battery current appears to be a derived value (measured values are two charging sources and one load connection... The difference between those readings is the battery current). If there is an electrical connection problem with the "sense leads" (poor connection, reversed connection, etc.), your FNDC may not calculate the correct battery current. (Do you have a DC Current Clamp meter you can compare FNDC battery current against measured battery current? You should be able to double check the basics--I.e., charging current from controller when no loads. Vs discharging current to loads when no charging current. See if the FNDC readings "match" the Charger and Inverter current readings and polarity).

There should also be a “Days Since Full” or may be labeled “Days since Parameters Met” value... What does that read? If the days counter is not reset back to zero, then the FNDC programming is indicating that the battery has never been fully charged.

Also, check the battery Absorb voltage for the controller vs the FNDC... If the controller is set to 14.6 volts, the FNDC should be set to ~14.4 volts. Also, check the battery voltage as reported by the FNDC (supposed to be the most accurate in an Outback system) against the MPPT charge controller's displayed battery voltage. If the MPPT controller is set for 14.6 volts Absorb, but reads 14.3 volts on the FNDC, then the MPPT controller will think the batteries are full when the FNDC does not.

-Bill

mtdoc

Re: Ensuring I am doing the right thing

The LINK I posted earlier tells how to set up and calibrate the FNDC. Why they don't put this info in the manual, I have no idea.

The FNDC resets to 100% Soc when it is turned off or unplugged from the Hub by it's ethernet cable. So the bottom line is that to get it calibrated you need to FULLY charge your batteries per manufacturers specs with whatever charging source(s) will ensure this (PV, generator, grid, etc). Then unplug the FNDC and plug it back in.

Bill - FYI the FNDC and Outback inverter are both programmed with the Mate (via a "Hub") - so charging parameters are not entered for the FNDC seperately. It does measure battery voltage accurately with it's own leads direct to the battery terminals. The inverter and CC measured voltages can be offset to match this if needed. The FNDC will indeed display "days since charge parameters met" and these parameters can be set to be a specified return amps (aka end amps) and specified voltage for a specified time period.

Rngr275

Re: Ensuring I am doing the right thing

I have all the documentation, a Hub, and the Mate. Just a little nervous since this is my first go at equalizing and I am still getting to know my system.

BB I just found those videos last night just before your post... Thanks.

MTDOC... Thanks for your continued help we seem to have similar set ups.

All I regard to the video links... there is the charging video where the guy is explaining the settings in the charging menu and he says" Here is the Absorb voltage or sometimes referred to Bulk". So is it really bulk or absorb? Kind of nice to know since these voltages are different.

Nice and sunny today it looks like. Will wait till the batteries are pretty well charged the do the equalization.

Wish me luck.

Blackcherry04

Re: Ensuring I am doing the right thing

Rngr275 wrote: »

I have all the documentation, a Hub, and the Mate. Just a little nervous since this is my first go at equalizing and I am still getting to know my system.

BB I just found those videos last night just before your post... Thanks.

MTDOC... Thanks for your continued help we seem to have similar set ups.

All I regard to the video links... there is the charging video where the guy is explaining the settings in the charging menu and he says" Here is the Absorb voltage or sometimes referred to Bulk". So is it really bulk or absorb? Kind of nice to know since these voltages are different.

Nice and sunny today it looks like. Will wait till the batteries are pretty well charged the do the equalization.

Wish me luck.

You'll do fine, just watch the temperatures of the batteries. You should be there within a couple hours max. Check the SG every 30 minutes or so, when it stops rising, stop the equalization.

The terms come from a lot of places. most here use a 3 stage charging regimen, Bulk, Absorb and Float. I think most of the confusion comes from manufacturers trying to be a " Me Too " and jumbling the terms to hide what they really have. Equalization to us is a total different procedure to balance SG and Voltage.

Some have a " Full Stage " where they turn on and off the float, it drives me crazy just watching it. Some even have a 12 stage charging they use as a selling point. 3 stage will work out well for you and we'll all be on the same page.

BB.

Re: Ensuring I am doing the right thing

As BC04 says--measure SG every ~30 minutes "of all cells" and stop charging when the SG stops rising "in all cells" (this is equalization as we use the term--ensuring that all cells are fully charged by over charging some cells).

Bulk charging--That is the point at which the battery bank voltage is less than 14.5 volts (or whatever your "absorb" voltage is). The output of the charger is "current limited" (or limited to the amount of solar panel power due to sunlight conditions).

Absorb charging--That is when the battery voltage has reached the "absorb" point. The charge controller is now holding the absorb voltage and is reducing the current needed as the battery becomes fully charged over the next 2-6 hours or so.

There are a few controllers that have a "bulk voltage" setpoint... You may set it for 14.8 volts to dump lots of current into a charging battery bank. When 14.8 volts is reached, the charge controller goes to absorb setpoint (perhaps 14.5 volts) to drop current/voltage to the battery (batteries start to get hot/bubble a lot towards the last 10-20% of the charging cycle--reducing voltage/current at this point is better for long term battery life).

-Bill

Blackcherry04

Re: Ensuring I am doing the right thing

I do agree with Bill " All the cells " I usually make a chart and record them when I start. " Usually " but not always the lowest will be the last to come up. If that cell was stratified or just a lagger for some reason, then it might not be the last, depends on how the bank is formulated.

I almost think it's worse to leave one cell lower if your going to equalize in the first place then not doing it at all. Your adding insult to injury by creating a bigger problem for the future.

Rngr275

Re: Ensuring I am doing the right thing

Well it went medium at best. Clouds started coming and going about a half hour into the equalization. So I fired up the generator. Total equalization was for about 3 hours. Got nervous because I wasn't sure how a battery temperature was too high so I stopped the equalization (3hrs at 62V). I was checking my test cell all during the equalization and it was rising very slowly. The trojan support guy had told me to do 3hrs then start checking the cells. Anyway I think I stopped too early. My test cell came up from about 1.244 to around 1.261. Better but not to the 1.277 Trojan says is 100%. So my plan is to check the SG after work tomorrow just to see if the daily chrging brought it back up to the SG that I had tonight. Then I will do another EQ sometime this week.
FYI... I measured all the cells this evening and they ranged from 1.258-1.269 so I think that the batteries definitely need a good EQ.

Since the FX doesn't control the Midnight classic I went in the controller and set the EQ time for 4 hours and started the EQ manually. Did the same with the generator. I guess that is how to do it?

Blackcherry04

Re: Ensuring I am doing the right thing

It's no problem to take a break when doing a EQ. If you went 3 hrs it's probably a good thing, but you do have a large bank and big batteries. Once you get them up you'll be able to use the absorb cycle to keep up by adjusting the time. When your SG gets out of balance you can do it again.

I look at it this way, batteries are dying the day you install them. They will last a heck of a lot longer giving you good performance if you take care of them then they will if you do nothing and let them die from sulfation. I started in 1992 with my first set, I'v learned a lot since then. My wife says I worry more about them than I do her......lol

BB.

Re: Ensuring I am doing the right thing

In the end, 100% is whatever you get at the end of this process (temperature corrected maximum specific gravity). As batteries age and sulfate, the peak SG will fall over time.

From one of the Trojan manuals: Avoid charging at temperatures above 120°F (49°C)

-Bill

Rngr275

Re: Ensuring I am doing the right thing

The Trojan User Guide that came with my batteries and on there web site give voltages for 3 different types of charge: Daily charge 59.2v, Float Charge 52.8v, and EQ 62v. Is the daily charge the Absorb setting in my Classic 200? If so I might be under charging as mine is set to 58'ish, or is the daily charge the Bulk set point....

Wish the industry had some standard vocabulary.

Blackcherry04

Re: Ensuring I am doing the right thing

Rngr275 wrote: »

The Trojan User Guide that came with my batteries and on there web site give voltages for 3 different types of charge: Daily charge 59.2v, Float Charge 52.8v, and EQ 62v. Is the daily charge the Absorb setting in my Classic 200? If so I might be under charging as mine is set to 58'ish, or is the daily charge the Bulk set point....

Wish the industry had some standard vocabulary.

Your daily charge is you BULK Voltage, it is the trigger voltage. Once you reach it ( 59.2 ) then the controller will stop letting the voltage climb and you enter the absorb phase. In the Absorb Phase that voltage is held and the current is gradually tapering off. The tapering off is created by the batteries themselves. As they charge they can only accept so much current. The Float phase is triggered by Time or Ending Amps. Say you want, 2 hrs or 10 amps ending amps, ( what ever comes first ) Some controllers will hold the time to what you have it set at and disregard the ending amps, depends on how it's programed.

Think of the EQ as a total different operation. It has nothing to do with your your daily charge regimen.

Ending Amps can be a bit tricky, because if you have a load on system that is constant ( paradisaic ) you may never reach the ending amp setting. It's not so bad with Solar, but you can cook a set of batteries with a charge mode on grid.

It is confusing, it's the manufacturing and marketing people, no one seems to be on the same page. " Boost " is another one some throw in the mix.

vtmaps

Re: Ensuring I am doing the right thing

Rngr275 wrote: »

Is the daily charge the Absorb setting in my Classic 200? <snip> or is the daily charge the Bulk set point....

Wish the industry had some standard vocabulary.

I felt your pain once, but I got over it. I posted about it: http://forum.solar-electric.com/showthread.php?14738

The way Outback, Magnum, Midnite, Morningstar, and others use the terms 'bulk' and 'absorb' is not the way others use those terms.

The way your equipment works is:
Bulk: the only thing you can set is 'maximum current'. There is no 'bulk voltage' to set.
Absorb: For Absorb you have several settings. One setting is the 'Absorb voltage', which is the voltage that (when achieved) terminates Bulk. Once Bulk is terminated you stay at the Absorb voltage until certain conditions (which you may specify) are met (usually time or end amps).

Many (most?) battery and battery charger manufacturers use the terms 'Bulk' and 'Absorb' differently. Most batteries are charged from the grid, there is no load on the battery while charging, and there is only one charger on the battery. Therefore a different type of charging profile may be desirable, and these profiles may have different voltages for what they call 'bulk' and 'absorb'.

--vtMaps

Cariboocoot

Re: Ensuring I am doing the right thing

vtmaps wrote: »

The way Outback, Magnum, Midnite, Morningstar, and others use the terms 'bulk' and 'absorb' is not the way others use those terms.

--vtMaps

But it is the correct way to use the terms for RE applications.
Xantrex is one company that uses the term "Bulk Voltage" and causes panic when people look at their controller's output during Bulk stage and find the "Bulk Voltage" is too low.
Calling it "Absorb Voltage" makes sense because it is the constant Voltage held during the Absorb stage. The same with Float and Equalization.

Depending on the application, the charging profile and terminology used will vary for any given battery. In some cases the Voltage is forced way up to begin with and current tapered off along the way in such a manner as we might say it starts out in Absorb, which is why it gets called "Bulk Voltage" because the Voltage is actually maintained during the Bulk stage. But you are not likely to see this in an RE application. At least not a solar one.

Blackcherry04

Re: Ensuring I am doing the right thing

I guess my point would be Bulk Voltage stops when Absorption Voltage begins and the potential to reduce the current , mostly semantics. If Bulk Voltage is increasing, it has to reach the trigger point, that trigger point is the set absorption voltage, I don't recall talking about " setting it ". This only true if you do not follow the Interstate battery profile where they have increasing voltage during the absorption cycle. Been down that road before.