I thought I would update you on the changes I have made on the 12V side.
The main change was going to a LiFePo4 battery technology. If you put aside the claims and counter claims about cheap
& nasty Chinese batteries the basic technology makes a lot of sense. At least 3000 recharge cycles (perhaps 10000 if you believe the claims), ten year life, light weight/smaller and for me the big factor, able to charge at multiples of battery capacity (3-5C), quickly with little efficiency loss and no extended boost phase. Charge till full then hold at a float voltage.
It is early days, 3 weeks into the cruise
but so far I am pretty happy. It does not suffer from Peukerts factor losses and perhaps because of this we seem to use less power. I can't be specific as we also did a number of LED light changes. Charging on alternators is much quicker, I now wish I had a bigger alternator or at least a smart regulator so I could tailor the charging profile.
The standard voltage is higher (13.2 or so) and one side effect is I can use the windless without running the motors if I have to!
I did a lot of online research
on options open to me in Aus. Basically there was a high end battery at rediculous prices, a mid price
range one that seemed to be good quality and a low end one that was subject to some argument about quality. The low end one required additional DIY charge management technology which brought the cost up a lot closer to the mid range "drop in" solution and transferred the risk back on you thanks to the DIY component.
I ended up buying
the mid range LifeTech battery. It has a 3 year warranty and is basically drop in. There are/may be a few changes to make in the charging regieme but not major. The cost was about double the cost of a good quality AGM
equivalent set. OK I did not seek out the best deal on AGMs but I had to justify the cost somehow!
The only change I am having to make (other than pad up my battery box) is to upgrade my solar
controller as my old "dumb" one did not support an appropriate on/off threshold. The standard shorepower charger on the LeadCalcium setting is fine (14.6V full charge voltage).
I have also had to remove my VSR as the Lead Calcium Starboard battery can't share the charge pool due to the different charge profile. More on this in a later post.
I have replaced the 300Ah bank with 180Ah of LifePo4. They can safely be discharged to 20% DOC giving you about 150Ah or the equivalent of the 300Ah at 50% DOC. As they are smaller there is room for more in the box if you need and can afford more.