Hi John
I have followed this interesting thread, reading most all posts thoroughly. Seems obvious that the cutting edge battery types and charger configurations mentioned are by far exemplary of "current" [pun intended] best-in-class DC power systems for boats. Also, it is clear that you guys are having a blast working this new, expensive battery/charger opportunity to its fullest capabilities. Bravo to you all!
Although such as you mention... "maybe decades of lifetime, thousands of cycles if properly cared for" ... "to the point cheaper than quality lead over the years even at triple the price up front"
My question: With DC battery and charger technology consistently making strides for better and better options, isn't it a bit overboard [again a slight pun here] to put all that cash into a boat's DC system that could provide - "maybe decades of lifetime, thousands of cycles if properly cared for" - when this expensive DC system will likely become surpassed/outmoded by newer/better DC systems in the not too distant future?
I ask that question for the good of general boaters, especially for the respect of newbies, who may not be flush with cash... but... may begin to feel that they too need to spend thousands upon thousands of dollars trying to "keep up with the Joneses".
For the good of most boaters, feel I must repeat the old adage, : Unless of course a person simply likes to spend cash and many hours effort for improved DC system [which is perfectly OK it that's what is desired]... "If it ain't broke, don't fix it!"
Art, when you say that
"this expensive DC system will likely become surpassed/outmoded by newer/better DC systems in the not too distant future" you're probably right, but the opportunities for improvement outside of lowering manufacturing cost may be somewhat limited when you are talking about LiFePO4 batteries. The ideal DC battery has at least these characteristics:
1. Cheap
2. No maintenance
3. Works with existing charging technologies
4. 100% energy efficient on charge and discharge (take out 100 Ah, recharge to full with 100 Ah)
5. Lightweight with super high energy density (Ah per pound)
6. No loss of capacity over time (infinite cycles)
7. Safe
As near as I can tell, these batteries meet all of the above except "cheap" about as closely as may be practically possible, so the chance of
dramatically improving on them seems less likely than you suggest.
Maintenance - I turn them on when I use them and off when I don't. Beyond that, there isn't anything to do, maintenance wise.
Charging - I'm able to use my existing Trace charger/inverter and Balmar controlled voltage regulation. Some may not have equivalent equipment but the charging requirements of these batteries are explicit, but seem pretty easy to provide.
Efficiency - Maybe 95% - 98%. Not sure, but so far I see almost no energy not being stored by the battery. On discharge, there is almost no voltage drop even with high loads. Battery at 26.3 volts, turn on 85 amp 24v inverted load (microwave), battery drops maybe to 26.2 volts. Much better on all electrical equipment. 80% of the bank rated capacity is routinely available for consumption, double that of FLA, but probably an area that will be improved upon.
Weight - these are certainly a lot lighter than flooded lead acid but maybe a lighter battery will come down the pike.
Cycles - I doubt any of us could outlive the number of cycles these batteries will deliver if managed with no greater skills required than for any other battery.
Safety - these are safer than FLA, but both seem safe enough to me.
In other words, sure, this technology will be improved upon but in the terms of what a battery bank is supposed to do on a boat, I don't see a whole lot of room for improvement. Except cost.
Factors to consider regarding cost - if you spend your time at the dock, mostly, then you don't need fancy batteries. If you spend a lot of time cruising or on the hook then the cost per cycle on Lithium batteries is as low or much lower than other alternatives.
