My experience with lithium batteries

Hello, My name is Massimo Orlandini, (forgive my English, helped by the translator...) there is a lot of talk about lithium batteries and at the invitation of Matteo Salamon, I would like to share my experience:

I have created a few dozen systems with lithium batteries, (no drop-in), from 3 to 50 Kw/h.  Lead acid batteries, which for years have represented the only possible storage solution, have limits: the usable capacity is around 50% of the nominal capacity, their efficiency starts from 75% and reduces considerably every year of life; the charging cycles should be completed every time, (Bulk/Absorption/Float), otherwise there is a risk of partial sulfation which quickly reduces the life of the batteries.

Lithium batteries, in particular LiFePo4, have simplified the use of storage systems, they can be charged very quickly with very high currents, they have practically no memory effect, their efficiency is close to 99%. On the other hand, systems with lithium batteries must take into account safety features that must NOT be neglected. The charging system (battery charger and alternator) MUST STOP charging once the BMS removes charging permission, otherwise the energy received from the already charged batteries is converted into heat, and if it is hundreds of amperes we are talking about KW, which can quickly lead to the "thermal runway" with unpleasant consequences.

Another important consideration, especially on boats, is to create a redundancy in the power supply of the essential systems in the event of a blackout of the service batteries, because the BMS can interrupt the supply for various reasons and this is not a good thing on a boat! 

That said, I believe that carefully installed lithium batteries offer performance that helps you enjoy your boats. Those who have sufficient knowledge can create lithium systems with material purchased on the internet at truly convenient prices, now comparable to lead acid, but for those who do not have specific skills, I suggest turning to professionals in the sector who use branded material for whom it is possible to find staff almost everywhere... There is a lot of talk about fires due to lithium, but in the same way they talk about galvanic corrosion every time a phenomenon cannot be explained... just as we once blamed witches.

Fair winds, Massimo