Starting your marine diesel engine with 4s 280a LFP ?

[LFP addict]

Got a 3cyl Mitsubishi 25Hp diesel engine. My engine manual does not say anything about minimal starting currents.

The 4S 280a LFP has 1 c. So it can deliver only 280a , would that be enough ?

 

[jasonhc73]

Not a great idea.

Lithium just not suitable for cranking like lead acid.

You can certainly make it work. But consider this. Massive current on a cold lithium battery is absolutely disasterous for them.

If you don't have a spec sheet from the supplier or manufacturer assume 1C continuous. Many are capable of 2C contuous, but in short bursts some even have 5C and 10C ratings. However 280ah cells are not really any different than 50 or 100 ah cells, but just more medium for chemical storage.

The internal connectors are basically identical.

 

[codfish]

Got a 3cyl Mitsubishi 25Hp diesel engine. My engine manual does not say anything about minimal starting currents.

The 4S 280a LFP has 1 c. So it can deliver only 280a , would that be enough ?

I built a starting battery for my 40 HP Yanmar. I used 4s, 90ah Eve cells rated for 3C. i.e. 270 amps
The Yanmar has a starting surge amps for a small fraction of a second, and a "running" maximum of 250 amps, till the engine starts.
The 4s 90ah LFP starts it faster than the default Pb ever did.
I purchased the 4x 90ah batteries as an "add-on" to an order of 280ah batteries. The total, delivered cost for the 90ah add-on was less than $200. In other words about what I would have paid for a quality Pb battery.


But you need to consider your whole system. You don’t mention your house battery but If you are thinking just a 280ah as a combined starting and house battery, it will likely burn out your alternator if you run the engine direct to a depleted 280ah LFP battery.