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50% average discharge = 1000 cycles

70% average discharge = 650 cycles

95% average discharge = 400 cycles

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Now let's say I want a camper that has a

**useable**255 amp hour battery bank. Traditional logic (and many folks here on expo) would say that I should buy TWO 255ah 12v batteries, or double the capacity I want to use, and never exceed 50% discharge. In this case, total cost for the batteries would be $1300. Total weight would be 312 pounds (each battery weighs 156#). They would last me for 1000 cycles, or

**500 cycles PER battery**.

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Now let's compare that to just one battery that is basically fully discharged to 95%. It would get roughly 400 cycles, which is 20% less cycles than the double capacity,

**but**you save 50% of the weight. That's 20% less capacity, 50% less weight. Seems like a reasonable trade-off to me.

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Let's go a little deeper and propose that the dual battery combo may actually

**cost more**in the long run. Why? Well, 156# extra over the course of tens of thousands of road miles = worse gas mileage. Even if that 156# only reduces gas mileage by, let's say, 0.2mpg, it would still have a significant impact on fuel costs over 5 years. The amount saved on fuel could easily pay for the 20% difference in cost.

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The vehicle would also handle better with less weight, etc, etc. Basically the point of this thread is to point out that discharging a battery beyond 50% is not the deadly sin it is made out to be. In fact, it may actually be an economically better choice, and reduce weight in a camper.

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AGREE? DISAGREE? DISCUSS!!!!!