Switch to Lithium without DC to DC or Li-BIM?

[Tom Cherry]

2 hours ago, Grey Goose said:

I am also able to turn off my inverter functionality from my Magnum remote. It draws about 1/4 amps DC in this MODE as verified with an amp clamp at the inverter. 

EDITED to define OFF vs STANDBY and HOW it actually WORKS....

Technically, it is NOT OFF.  It is in STANDBY.  When it is OFF, there will be NO DRAIN or Draw.  When you are using the Magnum to charge batteries or inverting, the draw is about 4 Amps..  Measured by our CHIEF Electronic's Expert, Frank McElroy and also confirmed by Magnum.

At the SLIGHEST or milliamp draw due to any phone charger load or higher 120 VAC LOAD..., the inverter automatically goes to INVERTING.  Thus the 4 amp draw.  If you leave a MH in storage for a day, using your own 0.25 Amp draw, that is 6 AMP HOURS of draw or 42 Amp Hours in a week.  You only have 220/225 AH of USABLE Capacity...if you only drain the batteries to 50% of their capacity.  Therefore, in a little over a MONTH, you have drained them to 50%. BUT....READ ON....

That ALSO means that you have to have EVERY OUTLET free of any load.  Leave a TV on standby...leave the microwave on. SO, it is considered as BAD PRACTICE to LEAVE the Magnum in the STANDBY MODE.  It needs to be PHYSICALLY turned off on the inverter....SO, if you want to have NO Parasitic Load on the Magnum, you MUST turn it off.

There are folks that have installed TENDERS or Trickle chargers (the high performance ones....the ones that have multistage charging and also desulfonate).  That keeps the Batteries. UP.  BUT, if you leave ON the Inverter, you run the risk of it going into ON MODE...and it will NOT go back to sleep like some electronics.

THUS, a 4 amp tender (PulseTech makes a great one....for $40 on Amazon), then you barely keep the House charged.

I don't dispute your measurement and you have given us the data, that we had before and verified.

BUT, if you intend to store the MH for extended periods of time...  EITHER DISCONNECT the batteries...  Remember, there are TWO CIRCUITS (some MH's have a DEFEAT SWITCH on a Circuit Board) that are parasitic.  The CO and Propane detector.  THEY DRAW CURRENT DIRECTLY....not through the Disconnect switch.  In addition, many of us have NO OFF SWITCH on our Inverters. 

NOW if you go to MTI and check the Propane detector....It draws 90 Milliaamps... The CO detector draws 108 ma.  That is a total of .2 Amp (rounded...0.18 Amps This is common on all inverters after 2005.  The Dynasty has a 400 Amp Breaker for the Invterter.  It is HOT WIRED to the BATTERIES.  It can NOT BE TURNED OFF... You must use the Inverter switch. 

SO, recalculate.  250 Ma + 200 ma....that equals 0.45 AMPS....times 24  = 10.8 AH per day.  Times 7 = 75.6 AH per week.  NOW divide 225 by 75.6 = 2.97 WEEKS or you will run down a typical 440/450 AH house bank in THREE (3 ) weeks....assuming you honor the recommended 50% SOC or only drain out 225 AH.  NOW, turn OFF as in PUSH the OFF button....then you have 0.2 Amps or 4.8 AH per day.. times 7 = 33.6 AH per week.  Divide 225 by 33.6 = you will get almost 7 WEEKS ... without breaking the 50% rule if you TURN OFF the Inverter at the INVERTER SWITCH. 

NOW...speaking of Inverters.  SOME are wired through the House Disconnect Switch.  the later ones are NOT.  The Dynasty (2800 Watt for Res Refer circa 2005 and higher) have a DIRECT FUSE (400 Amp) and the Camelots have a 300 Amp fuse.  ONLY WAY to shut down.... PUSH THE BUTTON...

Thanks for the comment....it is a teaching moment that is needed and this is an opportunity to disspell the MYTH that one can TURN OFF A MAGNUM from the remote.  It also addresses the Parasitic loads from the SAFETY equipment.

 

[Grey Goose]

45 minutes ago, Tom Cherry said:

Technically, it is NOT OFF.  It is in STANDBY.  When it is OFF, there will be NO DRAIN or Draw.  When you are using the Magnum to charge batteries or inverting, the draw is about 4 Amps..  Measured by our CHIEF Electronic's Expert, Frank McElroy and also confirmed by Magnum.

At the SLIGHEST or milliamp draw due to any phone charger load or higher 120 VAC LOAD..., the inverter automatically goes to INVERTING.  Thus the 4 amp draw.  If you leave a MH in storage for a day, using your own 0.25 Amp draw, that is 6 AMP HOURS of draw or 42 Amp Hours in a week.  You only have 220/225 AH of USABLE Capacity...if you only drain the batteries to 50% of their capacity.  Therefore, in a little over a MONTH, you have drained them to 50%. BUT....READ ON....

That ALSO means that you have to have EVERY OUTLET free of any load.  Leave a TV on standby...leave the microwave on. SO, it is bad practice to LEAVE the Magnum in the STANDBY MODE.  It needs to be PHYSICALLY turned off on the inverter....SO, if you want to have NO Parasitic Load on the Magnum, you MUST turn it off.

 

There may be a misunderstanding so I will try to clarify. When I push the inverter ON/OFF button on my Magnum remote it stops the inverter functionality. I know this as measured by a meter and by noticing that things like my clock on the microwave display goes off. At that point it will never provide any AC power what so ever regardless if there is a demand or not...UNTIL I press the on button on the remote. Yes the unit is still using some power at that point as it still has to communicate to the remote. I measured  about 1/4 amp as measured by an AMP clamp at the inverter DC input. This is similar to a TV that is OFF but still consuming some power. 

And technically Inverter Standby mode is for when you have AC power from shore or the generator. This is per the Magnum Manual. This is separate from standby charger mode.

Edited August 22 by Grey Goose

[Tom Cherry]

19 minutes ago, Grey Goose said:

There may be a misunderstanding so I will try to clarify. When I push the ON/OFF button on my Magnum remote it stops the inverter functionality. I know this as measured by a meter and by noticing that things like my clock on the microwave display goes off. At that point it will never provide any AC power what so ever regardless if there is a demand or not...UNTIL I press the on button on the remote. Yes the unit is still using some power at that point as it still has to communicate to the remote. I measured  about 1/4 amp as measured by an AMP clamp at the inverter DC input. This is similar to a TV that is OFF but still consuming some power. 

And technically Inverter Standby mode is for when you have AC power from shore or the generator. This is per the Magnum Manual. This is separate from standby charger mode.

Well....now we have what is called...."a difference".  Magnum says that when you push the OFF BUTTON....that does NOT turn it off....that puts it in STANDBY.  I took them at their word because they said it was a common misconception and often the inverter was NOT OFF....but still could be instantly powered on.

I just checked MINE.  Yes, you are correct.  You turn it off...and it shuts off the POWER....flashing Microwave lights.

BUT, I also turned all all the DC lights and the draw was approaching 0.5 Amps or 500 Milliamps.

SO...the advice still stands.  if you do NOT WANT any Parasitic DRAW from the INVERTER....you have to PHYCSICALLY turn it off on the Inverter. 

Otherwise, with the TWO detectors, you will not get but THREE WEEKS, MAX, from a fully charged House bank (4 cells equivalent to 225 AMP HOURS of Capacity.

Then, if you kill the Magnum or turn it off....then you will get around 7 weeks...

SO....here is what I don't fully understand....or need confirmation on.  If you install FOUR 100 AH Lithium batteries....you have them in PARALLEL....obviously NOT IN SERIES.  SO, you have 400 AMP Hours of life.  Somewhere I read or thought I read....that you really did NOT want to go below  20%....compared to a FLA of 50%.  SO, you have 320 AH of usable capacity.  Is that correct?

OK....then you would do the math based on that....and you have 42% MORE USABLE capacity...as you can discharge then down to 80%...  Thus at 80% DISCHARGED, you will get a smidge over 4 WEEKS of capacity if you leave the Magnum in STANDBY (Remote turns it off) and the two Detectors ON.

Thus.... the if you DO turn OFF the Magnum at the POWER BUTTON (not the Remote), you will get about 9.5 Weeks before the Lithiums break the 20% SOC limit.

Learned something.  YES, Magnum and what I posted was right....You do NOT TURN OFF the Inverter when you use the remote.  It puts it into STANDBY...so that when you switch it ON...it POPS TO LIFE.  But the price of Standby is a 1/4 AH drain...and that adds up....especially with the REMOTE ONLY standby mode.

That also points out a different issue....one that has plagued MAGNUM.  When a remote starts to fail....the Remote acts FUNKY.  My first complaint....the Magnum would NOT TURN ON..... If it was ON 50 A...it would NOT COME OUT OF STANDBY as it SHOULD.  It stayed off.  We traveled for a few hours and DW said....There ain't NO LIGHT in the Res Refer.  SO, I pushed the button.  It then did that repeatedly and I had to MANUALLY turn it on.  That is a BAD CONDITION....like when you lose POWER in storage....a common occurrence....the Charger did NOT come back on.  I had other remote issues and Magnum helped me troubleshoot.  

Thanks for the Feedback.  We are on the same page....just different terminalogy and I have verified...and will EDIT my previous post....

[Grey Goose]

3 hours ago, Tom Cherry said:

Well....now we have what is called...."a difference".  Magnum says that when you push the OFF BUTTON....that does NOT turn it off....that puts it in STANDBY.  I took them at their word because they said it was a common misconception and often the inverter was NOT OFF....but still could be instantly powered on.

I just checked MINE.  Yes, you are correct.  You turn it off...and it shuts off the POWER....flashing Microwave lights.

BUT, I also turned all all the DC lights and the draw was approaching 0.5 Amps or 500 Milliamps.

SO...the advice still stands.  if you do NOT WANT any Parasitic DRAW from the INVERTER....you have to PHYCSICALLY turn it off on the Inverter. 

Otherwise, with the TWO detectors, you will not get but THREE WEEKS, MAX, from a fully charged House bank (4 cells equivalent to 225 AMP HOURS of Capacity.

Then, if you kill the Magnum or turn it off....then you will get around 7 weeks...

SO....here is what I don't fully understand....or need confirmation on.  If you install FOUR 100 AH Lithium batteries....you have them in PARALLEL....obviously NOT IN SERIES.  SO, you have 400 AMP Hours of life.  Somewhere I read or thought I read....that you really did NOT want to go below  20%....compared to a FLA of 50%.  SO, you have 320 AH of usable capacity.  Is that correct?

OK....then you would do the math based on that....and you have 42% MORE USABLE capacity...as you can discharge then down to 80%...  Thus at 80% DISCHARGED, you will get a smidge over 4 WEEKS of capacity if you leave the Magnum in STANDBY (Remote turns it off) and the two Detectors ON.

Thus.... the if you DO turn OFF the Magnum at the POWER BUTTON (not the Remote), you will get about 9.5 Weeks before the Lithiums break the 20% SOC limit.

Learned something.  YES, Magnum and what I posted was right....You do NOT TURN OFF the Inverter when you use the remote.  It puts it into STANDBY...so that when you switch it ON...it POPS TO LIFE.  But the price of Standby is a 1/4 AH drain...and that adds up....especially with the REMOTE ONLY standby mode.

That also points out a different issue....one that has plagued MAGNUM.  When a remote starts to fail....the Remote acts FUNKY.  My first complaint....the Magnum would NOT TURN ON..... If it was ON 50 A...it would NOT COME OUT OF STANDBY as it SHOULD.  It stayed off.  We traveled for a few hours and DW said....There ain't NO LIGHT in the Res Refer.  SO, I pushed the button.  It then did that repeatedly and I had to MANUALLY turn it on.  That is a BAD CONDITION....like when you lose POWER in storage....a common occurrence....the Charger did NOT come back on.  I had other remote issues and Magnum helped me troubleshoot.  

Thanks for the Feedback.  We are on the same page....just different terminalogy and I have verified...and will EDIT my previous post....

Tom, You covered several different subjects in this post but for clarification I would like to go back to the inverter on/off button on the remote. Much like you I am a bit of a stickler for details and want to avoid confusing the layperson who reads these forums. 

If the Magnum engineer used the term "standby" in the context you described, I feel this engineer did not communicate this concept well.

If you read the Magnum remote manual you will see the term standby called out in various scenarios relating to the inverter as well as the charger functionality. It will even reference the standby generator when referencing AC inputs.

But I reiterate this point.  When not connected to AC power pressing the on/off inverter button on the remote either turns the inverter function ON or OFF depending on the current state. Yes the Magnum inverter/charger will still be on to a certain degree...no different than the TV set that is waiting for you to push the power button on the remote. But if everything else stays the same it wont start inverting until you push the on/off button on the Magnum remote. If the Magnum engineer called this a standby state, then the engineer needs to read the manual.

Standby inverter mode would be when you are connected to AC power and you lose AC power/disconnect/brownout whatever the situation the inverter comes out of standby mode and does its thing to provide AC power. This is what automatically happens when I disconnect from shore power or turn off the generator, unless I press the inverter on/off button.

 

As taken directly from the manual: 5.2.1 Inverter Mode Turning the inverter on: Press the ON/OFF INVERTER button to activate the inverter function. The inverter will either be actively “inverting” by using power from the batteries to power the AC loads; or, the inverter will be “searching” for a load by using very little power from the batteries, if in Search mode. The green INV LED is on when the inverter is actively inverting, and the green INV LED fl ashes while searching. Turning the inverter off: While the inverter is actively inverting or searching, press the ON/OFF INVERTER button to switch the inverter function off. This turns the green INV LED off.

Inverter Standby – The inverter is in Inverter Standby mode when it is enabled (green INV LED is on) but not actively providing power from the batteries to the inverter loads. During Inverter Standby mode, the loads connected to the inverter are powered by the external AC power; however, if a blackout or brownout condition occurs, the inverter senses these conditions and starts inverting to power the inverter’s AC loads. CAUTION: If you have critical loads and are in Inverter Standby, do not press the ON/OFF INVERTER button to turn the inverter function off. If the green INV LED is off, inverter power will NOT be available to run your critical loads if the external AC power

Also when testing the inverter parasitic draw DC loads should not be a factor....IF you test for the load at the DC input on the inverter. The only variable then would be if you had parasitic AC loads on the inverter but that could be eliminated from the equation if you turn off the AC breakers.

I will defer the storage scenarios in this topic as I think there have been several topics discussing this already. But if I had to store lithium without shore power for long periods of time I would work out a way to have them disconnected to avoid fully draining. No different than I would for any other battery chemistry. With that being said some Lithium have built in low voltage disconnect so if something happened that would not allow the batteries to maintain charge they would likely recover better than typical FLA/AGM that were fully discharged for a period of time.

 

Edited August 22 by Grey Goose

[Mocephus]

6 hours ago, Tom Cherry said:

In regard to your inverter….and this comment goes back to Page 1, I KNOW this as a fact for the Magnums…and it would appear to work that way for yours…but maybe I understood.

The Magnum and perhaps your Xantrex can NOT be turned off from the remote.  The inverter may be in “standby”, like a TV, but when there is an AC load applied….it turns on and begins INVERTING.  Many posts and much debate and misunderstandings and misinformation and also discussion with Magnum.

The only way to “turn off” is to either do two things.  ONE push the OFF BUTTON on the inverter.  Some find this confusing as if you don’t hold in the button properly…no JOY.  Magnum even says….safest way…hold in….do the SOFT RESTART.  That actually reboots the inveerter.  It does NOT RESTART….so leave it alone.  Do not push the start button.  NOW, the inverter is off.  I think that an idle Magnum will pull upwards of 5 A DC….when one has “shut it off” from the remote.  I know that when the Magnum is inverting, there is a 5% loss of available power or the inverter’s internal electronics requires 5% of the battery capacity to operate.

NOW…those numbers are “typical” and each manufacturer has specs and such.

BUT…just pushing the OFF button on an inverter’s control panel will rarely, I think, physically turn off the actual inverter itself.

Thanks for the info….

Thank you Tom!

[Mocephus]

6 hours ago, RoadTripper2084 said:

This could be a problem since the LiFePO4 house battery will almost always maintain a higher voltage than the chassis. If this results in a constant drain from house-chassis it could be a problem as it could overcharge your chassis batteries and add a constant drain to your house battery. On the other hand, maybe it will act as an automatic battery-maintainer for the chassis, not certain...
 

On my Heart Interface Freedom 20 inverter (older sibling to the Xantrex?) there are dip switches on the back of the remote panel to configure its operation. One of these allows you to use the on/off switch on the front of the panel to manually enable the charger function (when external AC power is supplied via shore power or generator). When no external AC is available, the on/off switch controls the inverter function.  

Not sure of your model has the same features though, check the manual for your inverter.

Ken, excellent information. I definitely will check into that!