[cknuth]

Setup now changed to Custom.
Absorb 14.4V
Float 13.5V
Equalize 14.4V
Absorb Time 120 minutes.
Max Charge Rate 100%

The display indicates "Float Charging 13.5V 0A"
I've reset the battery monitor to "Full" 100% SOC

I think I'm where I want to be, right? Thinking of turning off the 30A breaker to the Magnum inverter to simulate a dry camping session. Run the inverted loads until say 12.6V, then bring the charger back in?

[folivier]

These charts are from Battleborn so you can figure out your SOC depending on the amps discharging.
Sounds like you're on the right path and getting closer to what you want.

[cknuth]

Those are excellent Forest. Thanks for sharing!

[Richard]

At the risk of sounding like a broken record, “listen to your batteries, they will tell you”. The trial that you ran where you looked at the batteries after 12 hrs, and they were at 13.4, tells me that the normal voltage at almost fully charged is 13.4. I would set the float at 13.4. Yes, I know BB’s recommendation is 13.6. You have already shown on your setup that value keeps the batteries at almost 100% SOC, and the system in perpetual charge state most of the time. BB may say their batteries are robust and can take it. My position is why take the chance. Other literature out there strongly suggests longer battery life if the steady state SOC is less that 90%. So it’s dealer’s choice on this one.

The downside is the battery bank rests at a slightly lower SOC, and if you want full charge for a longer term boondock, then you must go to Control and tell the charger to Absorb charge. The upside is a longer battery life.

My recommendations on how to set up the Lithiums are for pedestal to pedestal use, like we mostly do. There are more aggressive settings that a person wishing to stay off grid as long as possible would prefer.

My .02

Very very very clever idea on shutting off the breaker to the inverter to run a battery test trial and still have AC for the coach. Brilliant!

[folivier]

Just had a thought, I just installed a Victron Multiplus inverter/charger. It has a separate output to trickle charge a second battery at up to 4 amps, you might see if your inverter has this. It might take the place of the Amplstart charger, BUT only when the inverter/charger is charging.

[cknuth]

That's a nice feature, Forest. My Magnum doesn't do that. AmpLStart is sending me a new unit; after complying with all their voltage requirements, I could not get a charge into the start batteries. Will share a report after the swap is made.

Richard, again I agree with your thinking. I was creeping up my float voltage to accommodate the AmpLStart but fortunately find that wasn't the problem. Haven't done the dry camping simulation yet - kind of waiting for all the parts to be in place.

[Little]

Forest is your Victron the multi plus 11 that keeps the 120 legs separate? That one looks interesting. I am hoping that would be a changeup for the 2 Trace inverters in the LXI. Mine are on their last legs as Ive been doctoring them along. If yours is the multi plus 11 Id like to pick your brain a bit. Thanks, Mark

[folivier]

Mark mine is the multiplus not the new 11. Read up on that one, I'm not certain that it gives you 2 opposing legs of 120vac on battery power. It would be great if it does and I'm probably wrong but check anyway. There is a facebook Victron group with lots of info. I'd ask there. https://www.facebook.com/groups/victronusergroup/
You might also consider an auto transformer or step up transformer. These are much less expensive and IIRC give you 220vac from 120vac source.

[cknuth]

Semi-final report on the start battery/EchoCharge/inverter project referenced above.
AmpLStart has been functioning properly in Normal mode.  My float voltage of 13.4V does not require the Lithium setting.  

I did a stress test by turning off the inverter breaker and running lots of house loads; as the house voltage went below 12.8, the AmpLStart took the start battery off maintenance charge as expected.   

The inverter was turned back on at 12.7V - not a deep discharge - and it just went back into Float at 13.4V. up to 70A.    I would have expected an Absorb cycle at 14.4V.    At that point, the AmpLStart resumed its Maintenance charge to the start batteries. 

Photo below of my engine-bay charge controller setup.  The Sterling charges the house batteries from the engine alternator, limited to 60A.  The AmpLStart charges the start batteries from the house batteries/inverter, up to 15A.    They are manually switched so only one system operates at a time.
   

[Richard]

Woo Hoo !

You have discovered a quirk in the Magnum custom setup. Unless the battery is discharged much lower, it will not revert to absorb on charge. The reason for this is that it brings the battery voltage up to 13.4 and the amperage is based upon whatever the battery will take at that voltage. Since your charger max amperage is 120 amps, you were getting 60% or so of the max.

In everday pedestal to pedestal use, this is of little consequence. However, now that you are aware of what it does, and you want a 100% charge, go to Control on the panel, Charger, and place it in Bulk mode. This will charge the batteries the quickest and fullest. It will revert to float when it reaches the cutoff parameters you specified.

Thank you very much for closing the loop on this problem. Your journey will likely help others in the future with similar setups.