Thanks for linking our Blog - I was a bit too lazy to post new articles lately, but will do so in the near future.
Some answers to your initial questions:
Size of the bank: 400 Ah (4P4S 100 Ah Winston LiFePO4)
Bank/BMS completion: 09.2015
BMS: HousePower BMS with dedicated Low and High Voltage Cutoffs and a dedicated main contactor; LVC central, HVC "distributed" between charging sources. LVC warnings are generated by watching computed SoC. HVC should not happen normally.
protection: HVC indirectly cuts field current
; B+ directly connected to battery. No wind/hydro generator
, so no similar problem there.
Contactors/Relays: Tyco Kilovac EV2000 (LVC); 100 Amp rated relay for solar HVC; standard 12 V and 220 V relays for cutting alt field and charger shore power
of the entire boat: around 2.3 A. (Will subsequently work on reducing this by building coil optimizers for the various always-on 12 V relays.)
Starter battery: traditional Lead Acid. Charged by DC/DC charger from house bank, charging triggers on one of the following events
: ignition on, starter battery voltage lower than defined threshold, starter battery estimated SoC lower than defined threshold. Charging is maintained for at least 30 minutes after trigger disappears.
Dedicated small shore power charger, directly connected to starter battery to keep starter battery up without having to power up the house bank ("away from boat storage
Charging settings: all charging sources set to values between 13.8 (Victron Inverter/Charger, Victron BluePower solar chargers) and 14.0 V (Balmar MC 614/Alternator) for absorption, 13.3 V for float.
MC 614 senses alternator temperature via thermo sensor, in addition belt manager dials down field current
to 80 % (subject to more detailed adjustments).
Other thoughts: This design has been criticized for being too complex and I agree that it may be over the top for some people's needs.
However, I really had fun designing it, and being an EE I enjoy making things work the way I want them to. I am able to fix any problems myself and have spares and a plan B for almost any failure I could think of, hence no doubts about complexity in my camp.
I am currently working on adding some logic to keep SoC of the bank automatically in the 40 - 80 % range in what I call "lazy charging mode". This mode simulates HVC when reaching 80 % SoC and disables the simulated HVC event when reaching a predefined lower level (e. g. 40 %).
This "lazy mode" can be manually disabled for longer passages when extracting every single
Joule from available charging sources becomes important.
Our portable battery packs (I built two 40 Ah LiFePo4 batteries complete with BMS in water
resistant cases, normally driving the electric dinghy outboard
or other 12 V loads such as pumps or soldering irons...) can be hooked to the load bus on a "battery pack recharging station" in the aft locker box.
(The nice thing is: when left switched on there, they effectively expand the capacity of the house bank by an additional 80 Ah - they absorb charge and deliver current to the system.)