Xantrex inverter equalizing on it's own

[Tom Cherry]

12 minutes ago, jacwjames said:

I had been doing continual testing of the system since the RC7GS display failed.  But last week I left the charger off and monitored the battery level.  I had removed the display from the cabinet and unplugged it there and used the Victron BVM to monitor the voltage. 

Finally on Sunday the voltage went to 11.8 volt so I started the charging process, I plugged in the display momentarily and it was bulk charging.  As before the display started clicking and would flash back and forth between bulk and equalizing so I unplugged it.  I would periodically check the charging and finally the when it got to ~90% I plugged back in the monitor and it the charging had dropped to absorption charge.  This AM I checked and it had dropped to float charge. 

So the inverter itself is working as it should, but the display not so much>>>>but I am suppose to receive the replacement today. 

OK….the teaser.  WHAT was the VOLTAGE during the BULK Phase.  The Bulk phase is defined, by the battery manufacturers, as when the BULK of the current/voltage is pumped in.  Typically, when the amps drop to say 40 - 50….the. It is switching to ABSORB.  IF the BULK was in the 14.8 or slightly higher….the Inverter has a FLOODED Profile.  If the initial voltage was in the 14.1 - 14.4 Range….the inverted was operating in the GEL/AGM profile.

Thanks…..

[jacwjames]

39 minutes ago, Tom Cherry said:

OK….the teaser.  WHAT was the VOLTAGE during the BULK Phase.  The Bulk phase is defined, by the battery manufacturers, as when the BULK of the current/voltage is pumped in.  Typically, when the amps drop to say 40 - 50….the. It is switching to ABSORB.  IF the BULK was in the 14.8 or slightly higher….the Inverter has a FLOODED Profile.  If the initial voltage was in the 14.1 - 14.4 Range….the inverted was operating in the GEL/AGM profile.

Thanks…..

Highest I saw was 14.1 but the victron was only showing battery voltage, it started charging showing voltage that slowly climbed.  I wasn't camped out watching but would go out an periodically check.  When I checked at ~7:30PM the voltage was 14.1 but the display was showing absorption, so it could have been higher.   I might be able to go in and look at the charging history to confirm if it got any higher. 

In the past I really only used the Victron to confirm voltage since the RC7GS display seemed to be inconsistent when charging with the generator.   The last couple weeks has given me an opportunity to take advantage of all the Victron's capabilities.  I did set up low voltage alarm and it did alert me when the voltage dropped to 11.8 volts BUT you have to be close enough to the coach to connect via bluetooth!

[Tom Cherry]

1 minute ago, jacwjames said:

Highest I saw was 14.1 but the victron was only showing battery voltage, it started charging showing voltage that slowly climbed.  I wasn't camped out watching but would go out an periodically check.  When I checked at ~7:30PM the voltage was 14.1 but the display was showing absorption, so it could have been higher.   I might be able to go in and look at the charging history to confirm if it got any higher. 

In the past I really only used the Victron to confirm voltage since the RC7GS display seemed to be inconsistent when charging with the generator.   The last couple weeks has given me an opportunity to take advantage of all the Victron's capabilities.  I did set up low voltage alarm and it did alert me when the voltage dropped to 11.8 volts BUT you have to be close enough to the coach to connect via bluetooth!

MY GUESS….  The Xantrex is operating on the defaults.  The profile is GEL/AGM. Not an issue for, PER TROJAN, a few years…but the continued BULK charge of 14.1 - 14.2 will result in minor or accelerated sulfonation….and you will not get full life expectancy.  The tech was sharp and also could explain things in common terms.

You won’t see any near term effects…but if you wanted to “continue and offset” the sulfonation….then a PusleTech desulfurization module would help….

Hope the new, to you, remote works….

[jacwjames]

Here is a screen shot on the trends for the house battery voltage.  Voltage did get to 14.4 volts and now has settled down to 13.3 volts.    When I look at the screen it shows what the battery voltage is not the charge rate so it's hard to tell what the charge rate is.

But it looks like it might be charging at the AGM battery rate. 

Edited Monday at 03:15 PM by jacwjames

[Tom Cherry]

58 minutes ago, jacwjames said:

Here is a screen shot on the trends for the house battery voltage.  Voltage did get to 14.4 volts and now has settled down to 13.3 volts.    When I look at the screen it shows what the battery voltage is not the charge rate so it's hard to tell what the charge rate is.

But it looks like it might be charging at the AGM battery rate. 

Based on the “presumed” timeline….the charger started….then the profile settled in,  Amperage is a function of the 50% SOC.  A Magnum…and perhaps another member has “monitored” (yes….we do NEED a lfie….sometimes…LOL) the RC-7.  The voltage will be in the upper 14’s and the current will be 80 - 100 A…..then eventually….as in maybe 45 minutes to an hour (memory) start to drop….and as the BULK is filling the battery…the current will drop…say mid 40 and that, I think, trigger the stage shift from BULK to ABSORB.

The default appears to be GEL/AGM….as that voltage is for such.  The NEW (to you) remote needs to be throughly tested…from a 50% or run down SOC.  It the inverter doesn’t, using the Flooded profile, charge at 14.8 or in that range….either the remote is bad…or the inverter has an issue and will not maintain or recognize the flooded parameters.

For all practical purposes….again….a desulfonization PulseTech module will keep the batteries “OK”….thereby “salvaging” the bank….but ultimately a new (you have stated a preference for a PSW Dual IN Dual OUT Magnum) Inverter will be the end result.

Practically…install the PulseTech…return the used remote….assuming the right bulk voltage is not supplied…..and save your spare change.  When the batteries eventually fail…new Trojans and a new Magnum,

That would be my approach….

[jacwjames]

Success,

Finally got the new/used remote, plugged it in and it is working as it should.  Batteries had been charging so it showed it was float charging at ~13.3 volts. 

I did check and it was already set to Lead Acid battery, I'll double check all the settings tomorrow based on what I had in my notes.

I will do a battery test over the next couple days, taking the voltage down to 11.8 volts and then let it go through the bulk/absorption/float stages.

 

So looks like I got lucky.   Calling a Inverter Sales/Service business was kind of a shot in the dark but I figured if they do a lot of upgrades or replacement inverters they might have a remote. 

 

 

 

[96 EVO]

Thats great!

You gota get lucky once in a while 👍.

[Tom Cherry]

15 minutes ago, jacwjames said:

Success,

Finally got the new/used remote, plugged it in and it is working as it should.  Batteries had been charging so it showed it was float charging at ~13.3 volts. 

I did check and it was already set to Lead Acid battery, I'll double check all the settings tomorrow based on what I had in my notes.

I will do a battery test over the next couple days, taking the voltage down to 11.8 volts and then let it go through the bulk/absorption/float stages.

 

So looks like I got lucky.   Calling a Inverter Sales/Service business was kind of a shot in the dark but I figured if they do a lot of upgrades or replacement inverters they might have a remote. 

 

 

 

TRUST, but VERIFY.  Go ahead and drain them to around 11.8 or so….UNDER LOAD. Kill the load….and don’t have any AC power. Wait about 30 minutes.  Apply power.  Watch the remote….watch the Victron….and OF COURSE get out your DVM.  The charging voltage should be 14.8 or higher….if so….note the amps.  Keep that in your brain.  The BULK will eventually shift to ABSORB.  I’d note that…..then, all should be well.  I WOULD check in a week or so the setup parameters….

GREAT NEWS….

[96 EVO]

1 minute ago, Tom Cherry said:

   The charging voltage should be 14.8 or higher 

That's a little high.

I recall my Magnum will slowly reach 14.6V before switching to 'Absorb' mode.

Thats set for FLA batteries.

[jacwjames]

So I did a battery test and charge test yesterday.  The batteries held the voltage well, I turned on both exhaust fans and lights, and the batteries slooooowly depleted.  So every once in a while I'd run either the small toaster oven or microwave for ~3 minutes throughout the day, both showing ~1400 watts consumed as they were running.  Was taking forever so end I cycled the micorwave multiple times until the LBCO triggered the inverter to shut down at 12 volts @5PM.  The charger then kicked showing Bulk charging with the Victron display voltage climbing.  At ~8PM it dropped to Absorption.  This AM I checked and it was back down to float.

I did a screen shot of the charging profile as before but the X axis is not of the same scale, but the profile seems like it's slightly different, taking longer to bulk charge and "maybe" higher voltage.  But it still did not charge above 14.3 volts 

But I found white paper from a Xantrex tech who says the inverter will "attempt" to discharge 14.4 volts at maximum.  I'm falling a little short but wonder if this might be the result of be at a high equalization charge for a long period. 

So attached is a photo of yesterday's test of the charge profile in Blue and previous in RED

Also attached is the article I found. 

All in all I'm satisfied that the remote was my problem and the new/used on is working and that my batteries appear to be OK but I'm sure getting ~3 gallons of water boiled off them didn't do them any favors. 

 

Xantrex charge profile Tech7-Universal.pdf

[Tom Cherry]

12 minutes ago, jacwjames said:

So I did a battery test and charge test yesterday.  The batteries held the voltage well, I turned on both exhaust fans and lights, and the batteries slooooowly depleted.  So every once in a while I'd run either the small toaster oven or microwave for ~3 minutes throughout the day, both showing ~1400 watts consumed as they were running.  Was taking forever so end I cycled the micorwave multiple times until the LBCO triggered the inverter to shut down at 12 volts @5PM.  The charger then kicked showing Bulk charging with the Victron display voltage climbing.  At ~8PM it dropped to Absorption.  This AM I checked and it was back down to float.

I did a screen shot of the charging profile as before but the X axis is not of the same scale, but the profile seems like it's slightly different, taking longer to bulk charge and "maybe" higher voltage.  But it still did not charge above 14.3 volts 

But I found white paper from a Xantrex tech who says the inverter will "attempt" to discharge 14.4 volts at maximum.  I'm falling a little short but wonder if this might be the result of be at a high equalization charge for a long period. 

So attached is a photo of yesterday's test of the charge profile in Blue and previous in RED

Also attached is the article I found. 

All in all I'm satisfied that the remote was my problem and the new/used on is working and that my batteries appear to be OK but I'm sure getting ~3 gallons of water boiled off them didn't do them any favors. 

 

Xantrex charge profile Tech7-Universal.pdf 164.27 kB · 0 downloads

Sounds like it is working.  Others with a Xantrex might repeat your experiment.  Who KNOWS without having a high level “tech discussion” with Xantrex how they designed the inverter.

However, from many published sources by battery manufacturers and also inverters and some good solar sites…..

Flooded cells are supposed to be BULK charged at 14.8 (say 14.7 - 15.0)….that is a fact.

GEL/AGM are supposed to be in the 14.1 - 14.4 BULK range.

You are probably OK….and, who knows?  Maybe a NEW set would work that way???

NOW….always ONE for practical experiments….  If one “took off the surface charge” of one’s CHASSIS….so, at “rest” the DVM voltage was say 12.1 or so….

AND THEN….one disconnected the HOUSE Positive….put on a #2 “Jumper” with a bolt and nut and “insulated” that connection….temporarily….and then attached the other end of the Jumper to the Chassis…..then read the voltage.  If it was “still” in the 14.4 range….one could conclude…

Xantrex really did not follow the accepted “norm”….as does Magnum…..Magnum DOES use the higher voltage for the flooded parameter…..

OR….there is an “issue” in the “inverter or remote” that is preventing the correct Bulk Charging rate (voltage) for Flooded.

OR….ignore and go on,

What the takeaway is….higher voltage for Flooded and lower voltage for GEL/AGM is the industry’s (battery manufacturer) standard….

Never got into this….this deep before…but our GURU had read that somewhere before and confirmed it WAS correct.  NOW WE KNOW.

[jacwjames]

The more I play with the Victron VBM 712 the more I'm impressed with what you can do with it. 

I was playing with the trend function and found that I can back in history so I was able to put the last 3 charge cycles on one graph. 

The first two are with no remote connected and assume it is "thinking" I have AGM's, the last cycle is with the remote connected and it does charge higher.  So I believe the Inverter/charger are working correctly.  I also know that it is capable of higher charging voltage as when it was trying to equalize I was seeing +15.5 volts or higher. 

 

I am not an expert but they to educate myself, this has been a learning experience for me.   So when I was trying to find the charge profile for Lead Acid batteries I found says this

"The charger will
attempt to discharge 14.4 volts at its maximum
current in order to achieve the charge. Anything
higher can cause heat build-up; lower will slow
the charge rate. With this in mind, once the
voltage differential equalizes (battery voltage
meets the charger voltage, approximately 85%
charged), we enter the absorption stage.
In the absorption stage, the charger maintains the
14.4 volts, but the current will slowly drop as the
battery increases in resistance (caused by an
increase in charge level). Absorption stage will top
off the battery state of charge. Once the battery is
“full,” the charger will drop its voltage to 13.4
and transition to the float stage. The float voltage
level is high enough to keep the battery “full”,
even if DC loads are turned on, but low enough to
prevent persistent gassing of the battery which
can cause long term damage'

This is exactly what my Xantrex is doing.  Not sure why it might be different then other manufacturers but for now I'm going to assume mine is working correctly.  

In the past I never really paid attention to the the actual charge voltage, I guess ignorance is bliss.  I will definitely pay more attention in the future and now I know I can occasionally check with Victron I'm a happy camper. 

[96 EVO]

Our remote is mounted on a wall in the hallway so I'm often glancing at mine as I walk bye.