3d0g said:
It will be a 260Ah 12V LiFePO3 connected to a Victron Multiplus. I will probably use something like this to power the M1G:
https://www.xppower.com/portals/0/pdfs/SF_DDC40.pdf
The 15V version works down to 10V and can be trimmed up to 16.5V. Overkill, but I like that it comes with an enclosure and DIN rail mount.
Not sure why the M1G cannot simply be powered directly from the battery (with a proper fuse of course), but I guess it will pitch a fit if I do.
There has been previous discussion in several threads here about powering the M1 from the battery terminals only, with no input on the AC power terminals. At least one person was running their M1 using deep cycle marine batteries with a separate charger.
If your lithium ion batteries provide a solid 12V source, I think you could do the same thing, and avoid the need to boost the voltage to the 16.5V required when using the AC input terminals. One possible concern I would have is that somehow the internal charging circuit on the M1 would not be happy with the charging profile for Lithium-ion batteries. I don't think the M1 could damage the Lithium-ion batteries or their charger, since it will be drawing current from the battery, not trying to charge it (since there is no AC input). I can't think of how/why the lithium-ion charger would damage the M1, since it should never exceed about 12.6V, which is within the voltage range of lead-acid battery chargers. But maybe I'm missing something.
If you go this route, you would need to disable the AC Fail reporting, since there is no AC input. You'll also need to jumper the pins near the power switch to allow the M1 to power on with no AC input
Unfortunately, Spanky retired from Elk a few years ago, and doesn't seem to be active here any longer. He'd be the one who could provide an authoritative answer.
And yes, if you have a 260Ah battery, you definitely should put a 5A fuse at the battery to protect everything,