A recent scare, very recent, about old parts failing and no longer being available sent me again going around looking at the available options for me if our Magnum MS2000/ARC-50/MS-BMK shore charging/inverting system bellies up. Of course the search is different than in the past as it needs to be good for lithium, which really turns out to be the toughest part of it all, I think.
Preface by saying that I don't think that the standard lithium charge profiles offered are very good. Most are charge full out to 14.3v and shut off or maybe hold a while and then go to float or shut off. Nearly all the research I have done says going to that high a charge voltage is not good for battery life. Many also charge at very high rates, especially on smaller battery banks which is also getting shown to shorten life.
That said, I have chosen to shoot for charging at 13.8v or lower and stopping at a point that will put the SOC at rest indicated by 13.35v. Our current system does that by stopping at 13.8v and a charge rate of 60 amps to the 618ah bank.
The hang up point for me is that none of the chargers end with any criteria that is consistent to rest at the 13.35v. Voltage and time don't cut it and vary wildly in rested voltage. I tested that on our test setup trip.
The Magnum is about the only standalone shore charger that can do it because it terminates off volts and amps. An integrated system like Victron can do it but is much more complicated and centralized.
In my searching, I stumbled across a setup that might actually be as good and maybe better than the Magnum for lithium batteries. It is a fairly recent Samlex addition to their line and much more sophisticated than their previous stuff.
It is fully programable for voltages and if float or shut off/rebulk, which is an essential set of needs. The thing that puts it over the edge on being useful is that it has an input that is setup for BMS input, but can also, it appears, be used to trigger from any dry contact switching item.
So, what the above does is make it so if you use a Victron battery monitor with the internal relay you can trigger the charger to shut off and rebulk, based on shunt based SOC measurements. I would set it for 95% full and 40% rebulk, probably, although we rarely if ever would be plugged in that long. I would expect very good repeatability with that setup.
Add this that there would be a cherry on the top, besides.
The Samlex has a solar controller input to it also, which is pretty odd as normally you would see the panels on that input not the controller. The manual is well over 100 pages, but it appears that the solar goes through the Samlex and is controlled the same as the shore power so it could be just set at the solar controller for fixed voltage output and the Samlex would stop the charging based on SOC. If this is true it would be a very nice thing.
A setup like this would not replace a fully integrated system like Avanti's Victron one, but would be for those of us that don't really want it all to be fully integrated into a potential single failure point. EG, I want at least on system to keep running if the rest die.
We will have a Wakespeed regulator on the alternator when the upgrade is done and it will charge to volts and amps and be very consistent, so that would also be covered.
We will stay with the Magnum and Blue Sky solar controller for now as it appears I will be able to fix the battery monitor error that the Magnum is getting currently. I have a new BMK kit coming for it as they are still available.
The Samlex shown is not a low cost item like many other Samlex stuff has been in the past, but appears to be ready to take on Magnum, Outback and the other higher end inverter chargers that cost even more.