Lithium Ferro Phosphate batteries, the do’s and don’ts

Per watthour, LFP batteries are 4 times lighter, 3-4 times less voluminous than lead acid.  Because there is more effective energy content, you can buy smaller ones. That makes them competitive to lead-acid batteries. And because they live longer if you treat them nice, they can even be cheaper.

How to make them live long? Some do’s and don’ts.

  • The only maintenance is to balance them so now and then. Use a charger that is fit for this. The Battery Management System (BMS) inside starts charging till every little battery inside is at the same level, is balanced. Let that happen, don’t interrupt it.
  • You can discharge LFP till 10% of its capacity, but be nice and stop at 20%..
  • Don’t keep your LFP permanently at 100%.Configure your controller(s) of the solar panels and/or windgenerator that they stop charging at 90% or lower. If you leave your ship for a long time (in the winter), then discharge it to 70%. LFP doesnot discharge that much, so at the end of the winter
  • Take care for your alternator attached to the dieselengine. LFP ‘sucks’ the energy out of it, so the alternator is working on full power continuously, it gets hot and overworked. Same with the propshaft alternator. Ask the installer to put a limiter in between. There are more solutions, like connecting him to a lead acid battery, in case you combine this.
  • If the BMS makes the contactor switch off the energy to and from the battery, make sure that also your alternator(s) stop at the same time. This prevents the alternator to ‘blow up’ (diodes blow up mostly).
  • keep the contact bolds greased.

That’s it!