How Do I Prevent My Classic 150 from Ever Going over 15V?

[Halfcrazy]

Tom
Excellent catch. So when the Magnum is online charging it elevates the Battery voltage. if this is the case the Classic should be producing 0 watts at this point and may even Say battery over V on the display.

Ryan

[boB]

My question would be,  withOUT the Magnum, does the Classic
by itself go to Absorb and hold the battery voltage there

If that was not the case, then I might tend to think that without the
Magnum inverter/charger connected that there was not enough
power available from solar only to get the battery voltage up there,
but when the Magnum was added that then there would be.

And THEN something might bring the voltage too high.

First thing to check is the high V limit in the LIMITS menu.
boB

[Westbranch]

Can we get a bit of info on those batteries?  age, performance, size, brand, model etc...
on the surface without PV specs it looks like you have balance, but 4 parallel batteries, maybe there is one bad one?

[mahendra]

may i suggest you checking the magnum voltage set points for charging . i have a similar issue with a morning star charge controller it has a float voltage of 13.7 where as my deka agm batteries has a recommended float voltage of between 13.4 to 13.6 So the morning star is overriding the classic and tries to float the batteries to 13.7 v. Point to note the morning star controller is only 15amps .So mysolution was to get another classic.|However that's your case. Recheck your magnum charge voltages.

[zulu]

I also have a Magnum MS2000 inverter/charger connected to this same battery bank.

When the Magnum is not connected to shore power (and therefore not charging the batteries), everything is hunky dory. Classic and Inverter work like a charm.

However, as soon as the Magnum is connected to shore power, the Classic's output starts creeping past 15V and when it hits 15.5V, the Magnum shuts down. Is this "dueling chargers"?

Not to butt in from the peanut gallery, but.

This sure sounds like the Magnum is the culprit here:

However, as soon as the Magnum is connected to shore power, the Classic's output starts creeping past 15V and when it hits 15.5V, the Magnum shuts down.

I am no expert but that seems to be the key statement here?

If by "The Classic Output" you mean "Battery Volts" then I suspect the inverters' charger is shoving power in to the batteries?

I know nothing of the Magnum inverters but the logical issue is it "only" happens when shore power is connected which seems to point to the Charger as the source of excess input? Does the Classic show battery amps into the batteries during these times?

Just saying.

Yeah, I guess that's why my Freedom 485 had the same fault.

Just saying.

My TriStar is waiting in the wings.

[Halfcrazy]

I don't think anyone here is blaming anything. We are all trying to help with your issue. I am not sure why you have to jump in with "My Morning Star is Waiting"? I am more than happy to personally call and walk through EVERY setting in the Classic. As of now there are a lot of questions waiting for answers so we can move forward helping you solve this issue.

Ryan

[boB]

Yeah, I guess that's why my Freedom 485 had the same fault.

This is the first I had heard of the Freedom inverter.   Did you also have a Freedom inverter connected
up to the system and the same thing happened ?

Still, the question that I have is, with ONLY the Classic connected, does the charger go into the Absorb stage ??
Or does it stay in Bulk MPPT ??

boB

[zulu]

This is the first I had heard of the Freedom inverter.   Did you also have a Freedom inverter connected
up to the system and the same thing happened ?

First I had a Magnum MS2000 hooked up and when Classic went 15.5V, the Magnum got smoked -- literally. I blamed the Magnum & sent it back for warranty work.

Next up, Freedom 485 (my original modified sine inverter/charger). Hooked it up with Classic and bingo Freedom faulted out because Classic exceeded 15.5V.

Finally, Magnum returned after warranty work. Hooked up Classic which went to what? -- yep, 15.5V -- and Magnum faulted out.

So I bought a TriStar because I start full timing this year & I really don't want to be a Classic beta site.

I have a month before I pull my RV out from storage and since I have the Classic still installed, I see what happens after I set a 15V or so upper Limit.

This will prevent my inverter from faulting out, but I'll see how Magnum and Classic behave together.

Interesting that a bad battery was mentioned because I may have had a bad one.

One of my 4, 6V Lifelines developed a leak at one of the terminals. I told Lifeline and they replaced ALL FOUR of my batteries! Now that's support.

Anyway, I'll start fresh in a month or so & let you know what happens.

BTW, I'm not alone: http://midnitesolar.com/smf_forum/index.php?topic=468.msg2785#msg2785

[Westbranch]

So, before you 'throw the switch', there is a lot you can scope out. 
Get a DC clamp meter and check the output from each battery in the bank to ensure all are equally contributing, having first re tightened all connections,
then do the same while the PV are charging, no inverter., again looking for a difference. then sheck out the inverter settings, etc ,etc, etc

hth

[Vic]

Hi zulu,

The MidNite Classic CCs have been shipping since late 2010.

They were well past Beta several years ago.

It DOES seem that you have some problems,  perhaps several of them.

The Classic does display the battery voltage on the LCD display,  but this does NOT  mean that the Classic is the device that is causing the battery voltage to be above its setpoint.  AND,  if you set the charge voltage Limit  in the Classic,  it will NOT keep the battery voltage from rising above this limit if the Classic is NOT the charger causing the voltage rise above your settings/desires.  This will simply keep the Classic from charging above this voltage.

You have been asked a question about the battery temperature,  which will change the charging voltage from those charge sources that use a Battery Temperature Sensor.  If the batteries are cold,  the charge voltage will be raised.

So,   since you have had several failures of your power system components,  it seems premature to just start blaming one device or another for these failures.  You will need to carefully observe what is occurring and take careful notes.

As was stated earlier,   you mentioned that when shorepower is disconnected,  that the Classic seems to do its job using PV input to charge your batteries.   So it seems very likely that the problem lies with any charger that runs from shorepower,  but NOT the Classic.

I am not associated with MidNite,   but I would guess that thre have been more than 10,000 Classic CCs shipped.   I have seen no reports similar to yours.

There have been very generous offers from those here to try to help you get your system working well.

If it is possible for you to get to your RV,  and take careful notes on the actions of each of the charge sources,  particularly the Classic CC,  with and without shorepower,  you may find the help that you are looking for.  When the Classic is charging your batteries there will be its charge state displayed in the lower right of the display,  the display  will show the output current,  the battery voltage and PV input voltage as well.  All of this INFORMATION is very important in helping you and others know just what is happening,  and what might resolve your problems.

Opinions are mine,   Thanks,   Vic

[Westbranch]

Vic brings up a good point, does the charger have a temp sensor as well as the Classic?? Either both are temp corrected or none are/should be corrected until you figure out what is wrong with your system...

[boB]

First I had a Magnum MS2000 hooked up and when Classic went 15.5V, the Magnum got smoked -- literally. I blamed the Magnum & sent it back for warranty work.

Next up, Freedom 485 (my original modified sine inverter/charger). Hooked it up with Classic and bingo Freedom faulted out because Classic exceeded 15.5V.

Yeah, an MS2012 (or was that an MMS ?) won't be hurt with 15.5 volts or even 16+ volts.  EQ voltages on the order of 15.5 volts
are common.  I am surprised that it  and also the Freedom 458 squaked at that voltage.  (I think you meant the Heart or Xantrex Freedom
458 inverter/charger)...

Finally, Magnum returned after warranty work. Hooked up Classic which went to what? -- yep, 15.5V -- and Magnum faulted out.

So I bought a TriStar because I start full timing this year & I really don't want to be a Classic beta site.

I have a month before I pull my RV out from storage and since I have the Classic still installed, I see what happens after I set a 15V or so upper Limit.

This will prevent my inverter from faulting out, but I'll see how Magnum and Classic behave together.

Interesting that a bad battery was mentioned because I may have had a bad one.

One of my 4, 6V Lifelines developed a leak at one of the terminals. I told Lifeline and they replaced ALL FOUR of my batteries! Now that's support.

Anyway, I'll start fresh in a month or so & let you know what happens.

BTW, I'm not alone: http://midnitesolar.com/smf_forum/index.php?topic=468.msg2785#msg2785

I still need to know if the charger state went out of Bulk MPPT and into Absorb without the inverter connected.

I notice that on that older thread you reference that that user never got back.  I am curious as to what happened there.

I have seen bad batteries not hold down the voltage when a load is suddenly removed but that would be extremely short
lived and on the order of maybe a second or maybe two.


Do you know about how long the voltage was sitting at 15.5 volts ?  If it stayed there for very long (more than a couple
of seconds), then there is either a setting wrong or maybe you even have a defective Classic.
If it is a bad Classic, I have never seen this particular problem.  There could always be a first time of course.

Another very useful piece of information would be to note the Classic output current when you see the voltage
sitting at 15.5 volts.   Is it 0.0 or 0.1 amps at that time ?  If the Classic is charging up the battery or a capacitor
and it is just taking time to discharge and for the voltage to drop back down, then you would see some current
at first and then it would drop to zero or very near 0.0 amps.

Thanks,
boB

[dgd]

First I had a Magnum MS2000 hooked up and when Classic went 15.5V, the Magnum got smoked -- literally. I blamed the Magnum & sent it back for warranty work.

Next up, Freedom 485 (my original modified sine inverter/charger). Hooked it up with Classic and bingo Freedom faulted out because Classic exceeded 15.5V.

Finally, Magnum returned after warranty work. Hooked up Classic which went to what? -- yep, 15.5V -- and Magnum faulted out.

So I bought a TriStar because I start full timing this year & I really don't want to be a Classic beta site.

I have a month before I pull my RV out from storage and since I have the Classic still installed, I see what happens after I set a 15V or so upper Limit.

This will prevent my inverter from faulting out, but I'll see how Magnum and Classic behave together.

BTW, I'm not alone: http://midnitesolar.com/smf_forum/index.php?topic=468.msg2785#msg2785

An interesting topic.. Zulu just a couple of small points. The voltage reading on the classic is the battery voltage. It is not a continuous reading of voltage the classic is putting out. If the only battery charging source is the classic (from PVs or turbines etc) then the voltage reading in conjunction with the battery amps the classic displays is showing the power going to the batteries/loads.
This as you say was all working good, no problems.

I note that you have not stated what the classic shows when the volts reach 15.5
Ie battery current, input voltage, watts and the classic status as shown in lower rhs of display, BULK MPPT, RESTING, etc..
Just this information would probably resolve what the problem is.

Then you connect the inverter. If this inverter was powering an ac load then the battery voltage as shown by the classic would normally reduce and if there was available power from PVs the classic battery current would increase.
Since this is not happening with you and the classic shows the battery voltage rising beyond the maximum charging voltages you configured into the classic then I would guess there is another charging source now charging and overcharging the batteries.
The fact that the classic's battery voltmeter shows this higher voltage is just the classic reporting the battery voltage it measures, it is NOT showing voltage being pushed by the classic into the batteries.

Although the smoking inverter, faulty batteries, temp measurement, old mod sine inverter may all be issues you appear to be leaning towards a problem with the classic. Maybe because you think the classic is still in beta testing, which is is NOT.

We need the data as displayed by the classic, please take a photo of the classics MNGP (display panel) or the local app screen when the classic is showing the battery voltage at 15.5 and post the photo here.

And your references to other message threads with same problem may appear similar but the original poster has not returned to explain how the issue was resolved or what the real problem was.

Dgd

[niel]

you have not tried to isolate the classic and pvs either to see if just the inverter/charger will still push a higher voltage. it is a matter of trying to isolate where the problem may lie. heck, i even think that there could be a problem emanating from the shore power connection with the possibility of ground loops or even miswired hot, neutral, and ground leads. anything is possible and getting the individual components to be operating with proper setting and seeing these results could help in tracking down where the problem originates. you also don't know if a tristar will fix the problem. it could still be something with your classic too as none of us know for sure at this point.

[dgd]

Zulu,

what happened? is the problem solved? you had people interested..

dgd