Switching to Lithium battery

I want to make my boat lighter, I currently have a 60 Ah lead battery (FIAMM L2 60) which weights 14 kg.

I was searching internet and found PowerBrick 40 Ah LiFePO battery and decided order one from mylithiumbattery.com The battery weights only 5.5 kg and can be used to replace lead batteries.

FIAMM L2 60 versus PowerBrick+ 40 Pro

PowerBrick conneted, all boat electronics are working nicely.

The battery was easy to install and boat electronics was working nicely, including my Selva Madeira 40 trim and also Atlas Micro Jacker hydraulic jack plate.
It was time to start the outboard. I turned the key and starter motor gave only a small click, nothing else happened. I measured the battery voltage and it was showing 2.26 V.
I was a little confused but then figured out that the BMS (battery management system) as protecting the battery, Selva Madeira starter motor was pulling too much current.
My PowerBrick+ is the Pro version so it can give 80 A. I switched back to lead battery and did current measurement test. Selva Madeira 40 starter motor draws more than 200 A so that the root cause of this problem.

I  thought 80 A is enough to crank this two cylinder 40 hp outboard but it's not! 😆

PowerBrick is not able to crank Selva Madeira 40 outboard.

Ok, this was my fault, I had bought a battery that is not suitable for my intended use, I contacted mylithiumbattery.com support and they were very helpful. They have a dedicated Li-Po battery for starting engines, it has only 16 Ah capacity but it can give 600 A!

I live in the EU area so it should be easy to mail the battery back to France and get a more suitable battery back. WRONG! I contacted thew local post office and global courier companies and when they hear word "lithium" they tell you that they are not going to ship you package regardless of the fact that LifePO batteries are very stable and considered safe. It seems that it not possible for a private person to mail lithium battery even inside the EU. There some companies that are handling dangerous items but it's very expensive and involves lots of bureaucracy.

I decided to order PowerStart 12v and then try to sell PowerBrick in Finland.

Once again mylithiumbattery.com delivered the battery very fast.

The PowerStart weights only 2.31 kg so it's 11.7 kg lighter than my lead battery!

I connected the PowerStart and tried to start Selva Madeira 40, bang, the outboard started straight away and quicker compared to lead battery.

My only concern is the 16 Ah capacity, I have automatic bilge pump that keeps rainwater out of my boat. I only charge the battery by running the outboard. So far I have not had any problems.