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

[zulu]

The Classic 150 in my RV is connected to two, 245W panels wired in parallel & to a 12V 4-battery bank @ 440Ah.

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"?

All the Classic charging voltages are well below 15V and I've turned off Equalization.

So, how do I prevent the Classic from EVER going over 15V?

[Halfcrazy]

First you need to be sure the parameters are set correctly in the Classic. Second you can go to limits and make sure the upper voltage is set low enough? I wonder if either the classic is programmed incorrectly or the battery is really cold and the temperature compensation is adjusting accordingly?

Tell us the average battery temperature and also tell us the absorb voltage set point in the Classic?

Ryan

[zulu]

First you need to be sure the parameters are set correctly in the Classic. Second you can go to limits and make sure the upper voltage is set low enough? I wonder if either the classic is programmed incorrectly or the battery is really cold and the temperature compensation is adjusting accordingly?

Tell us the average battery temperature and also tell us the absorb voltage set point in the Classic?

I can't do any of this now as my RV is in storage. I was hoping to find a sure-fire method of limiting output voltage regardless of temp, etc. before I swap out my Classic for a Morningstar.

As I remember, my Float & Absorb limits were both well under 15V, and as I said, Equalization was off.

So is there some parameter(s) I can set to ABSOLUTELY limit output voltage?

[Halfcrazy]

Yes the Limits menu has an absolute High and Low. Of course the only thing that can make the Classic go above its set point is temperature of the battery so these limits are hard limits

Ryan

[zulu]

Yes the Limits menu has an absolute High and Low. Of course the only thing that can make the Classic go above its set point is temperature of the battery so these limits are hard limits.

So the voltage set in Limits can (or can't) be overridden by temperature compensation?

[Halfcrazy]

The Limits menu is the HARD limit it will never be exceeded by that Classic

Ryan

[zulu]

The Limits menu is the HARD limit it will never be exceeded by that Classic.

Super.

But let's say I set the upper Limit at 14.3V (default Bulk voltage). If temp comp is not working properly, what's to prevent the Classic from just staying at 14.3V?

[Halfcrazy]

If temperature compensation ws not working? I assume you mean if the sensor is bad and thinks it is cold? If thats the case the voltage could be elevated but never above the Limit. of course this is not likely. Typically a faulted BTS will show open or shorted and default to 25c

Ryan

[zulu]

If temperature compensation ws not working? I assume you mean if the sensor is bad and thinks it is cold?

Nope -- as you mentioned in your 1st post, what if the Classic's programming is at fault?

[Halfcrazy]

I do not follow? If you program the set points wrong the Classic will follow what You told it to do?

Ryan

[zulu]

Oh, I see -- when you said "programmed wrong" I though you were talking about the Classic's firmware.

[Halfcrazy]

Sorry. No I was referring to the User programming.

Ryan

[zulu]

One more . . .

Should the Classic behave differently when my inverter is charging then when it isn't charging?

[Halfcrazy]

No if they are both wired correctly they should work completely independent of each other and simply try to charge the battery to the setpoint they have programmed in.

Ryan

[TomW]

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.

Tom