"Say you buy one battery and get 500 - 80% deep cycles.
Vs buying 4 batteries and get 2000 - 20% shallow cycles...
Your total cost in batteries may actually be the same."
I think there is much more than is normally considered here.
Yes if it equaled out that way, 4x's either way it would be the same. Probably is not exactly equal though or 4X's. Would you get 450 deep cycles or 550 deepcycles, most likely somehow you either win or loose but not exactly break even.
Then there is the self discharge, more batteries have more self discharge and require more charging to make up for it. So you got a bit of a loss on that end.
In todays world, what direction are batteries heading in price? Are we better off buying more today and makeing them last longer because higher demmand as more people go to RE power may drive up prices next year, or will prices drop because more sales are being made?
Will government over tax batteries because they don't like lead any time soon like they do everything else they don't like? Ciggarettes, alcohol, Freon, etc.. will Lead be next?
Right now we want our batteries to last a long life because of costs and such, in 2 years though will a much better battery be on the market for the same price or lower we would rather have? We hear alot of battery talk, when will we get them and for how much?
Buying 1/5th the batteries and getting 1/5 the life with deep cycles may not be so bad if we can buy a battery twice as good for the same price in 2 years. BUT if we still only have the same choices for batteries as now and they double in price then we should have bought them all now and shallow cycled them perhaps to get that longer life.
I think things like the above and other thoughts similar should also be considered at times. Right now we are in a rapid changing world.
Look at what happend to Solar pannels. Most people were thinking as demand increased manufactures would increase the supply and prices would drop, many waited for that drop. Instead they have gone far higher right now. So should we wait for a price drop latter this year or grab them now before they go even higher?
I have the same question about buying batteries and price changes as solar pannels.
And what about that NEW solar progress that was talked about and we have not yet seen that was supposed to lower prices? Is that the same with batteries, lots of talk about things we won't be getting?
Though with electric vehicles in the picture we may have a better chance of getting better batteries.
So for me, I really can't decide what is the best way to go, other than buying good used batteries and saving a ton of money, and I should get as many of those as I can at $10 compared to $70