Pulled the trigger on the cheapest LiFePO4 batteries anywhere. And I have a question.

[dlane1181]

As others have said, your starter motor likely exceeded the cranking amps for your new LiFeSO4 batteries.
I did something similar in an emergency situation when I combined batteries for an emergency cranking on a 6-cylinder Perkins diesel.

During subsequent discussions with RELiON tech support, I learned most LiFeSO4 batteries are limited to 100 cranking amps (some are 200 amps), unless specifically designed for start batteries. However, diesel starter motors, regardless of their rating, have a significant amp spike initially. The tech rep I spoke with is a mariner, too, and he gave me these data from his experiencing and experimenting. “I have 4-cylinder Cummins 4BTs and have measured an initial 1400A spike during start at 50F ambient temperature.”

[MVDarlin]

BMS will cut out at 100 amps after 2 seconds. You can add another lithium battery and double start bank to 200 amps if wired properly. Easier ti replace start with AGM. AGM setting on charger can accommodate Lithium as well.

[skenn_ie]

In general, batteries come in several shades. High-current low storage, and low-current, high storage. Plate thickness determines current capacity. Thin plates buckle more easily. Surface area determines Ah capacity. That applies to Lead-Acid, NiCd, Lithium, or even NiFe, though NiFe are low-energy density but almost indestructable.

[merrydolphin]

Li Fe are NOT recommend for start batteries. Keep your AGM or Wet cells for that function. Use Li fe for deep cycle house use.

[Rohan]

Just a short update.

Originally Posted by Jweyndling

Best to stay with lead acid for starting if you want to have a separate start battery.

And that's what I did. I put one AGM battery back on bank #1 as my start battery, and when running the engine, will leave that one selected so the alternator charges that one only. The LifePo4s are all hooked in parallel on bank #2 and hooked up to solar. Not the most sophisticated solution, but I want to keep it simple.

Originally Posted by KingRichard

second on the guy that said not to use zinc plated washers for conduction, tracking down a handful of copper will be worth the time. You'll have that same type of crappy connection like the solar panels

I did that as well. The 2/0 AWG battery cables are difficult in that space, so I still need some washers. I replaced the zinc ones with copper. Strangely enough, no hardware store had them anywhere. I had to order them on Amazon.