10 years....
Possible, but unlikely. It's that "properly sized" caveat which drops sand in the gears.
Most have published life cycle numbers of 1,000 cycles at 50% DoD. That's not 10 years - that's 3 years if you cycle it daily (for instance, off-grid solar).
(But even then, it's not like it'll be at full capacity and just suddenly keel over and sink after 1,000 cycles. By the time you get to 1,000, it will have been getting steadily worse for a while.)
And that's at 50% DoD, which would be a battery (or bank) that is double the size of the daily loads. So how much bigger do you have to go to "properly size" a battery (or bank) to last 10 years? According to Lifeline, you have to keep DoD at 20% or less to get 3,000 cycles:
So that would mean that a battery (or bank) "properly sized" to last 10 years of daily cycling, would have to be 5 times the daily load to keep the daily DoD at no more than 20%.
As I said - possible, but unlikely. Especially in a truck.
And, as I said - all lead-acid batteries...even the highest quality...are crap and only last a few years....unless you RADICALLY oversize the battery (or bank).
But let's consider that 50% number for a moment...
According to the 50% rule, you have to buy double the batteries you need to service the daily load, to get 1,000 cycles.
But what if you didn't? What if you only bought whatever size battery you need to service the daily load? According to that chart above, you're going to get 350-400 cycles going down to 100% DoD out of a LIfeline AGM. The U.S. Battery flooded battery has a bit better life cycle curve - it will get you 500 cycles at 100% DoD (Trojan T-105 flooded is the same BTW, and the Trojan L-16 2v flooded has an even better curve):
So...
A) You can buy double what you need - and pay twice as much. But it will last 1,000 cycles.
OR...
B) You can buy what you need - and pay half as much. But it will only last 500 cycles. So you have to do it twice as often.
Price wise, it's six of one, half dozen of the other.
EXCEPT...
By going with option B you only have to carry half as much weight.
(Which is why I personally just ignore the 50% rule. It's fine for solar powered buildings that don't have to carry around the extra weight, or boats that need the ballast - but for a truck, I'd rather carry half the weight and replace it twice as often. What the hell...it costs the same either way.)
