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Old 10-22-2008, 06:21 PM   #1
sarikan
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Battery life in terms of recharge times

Hi,
How many recharges do you think the DR1000S's batery can take? With users like some of us, who happens to use it everyday, it looks it will be charged everyday, sometimes twice a day.
Any ideas?

Kind regards
Seref
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Old 10-22-2008, 07:35 PM   #2
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About a year to a year and 1/2 I would guess.

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Old 10-22-2008, 11:37 PM   #3
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The Polymer Li-Ion Cells at http://www.batteryspace.com all seem have Cycle life > 500 times.

See also Prolonging your Battery’s Life.
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Old 10-23-2008, 08:35 AM   #4
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As wallcraft said the rough approximate figure is 500 cycles. So if it is charged every day that would be less than 2 years. However, batteries like to be charged before 0%. So if you charged it around 50% or 40% say twice every day, it may keep going for well over 1000 cycles and you could get over 2 years, despite being charged more often.

Although it is a different chemistry, I read reports from RC people testing new A123 cells using very high loads (model airplanes) having 80% of the original capacity left after 1000 cycles!!! I am not familiar with this type though. In any case the point is they could last a long time.

Just avoid going down to 0% (min 30% would be ideal) and you don't even have to charge it to full. Most hybrid/EV cars that are pushing for maxmum lifespan use 30%-80% range. Sure, they only use half the capacity but get amazing lifespan, thousands of cycles.

In practice it means you don't have to wait for 0% before charging and don't have to wait for 100% before removing from charge. Not sure if DR can display % charge as opposed to simply bars that are not very informative.
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Old 10-23-2008, 08:53 AM   #5
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Did a quick search and the most often quoted number is 500 cycles.
Seems nobody wants to supply a more accurate figure. Batteries are affected by so many factors (temperature, load, SOC, etc) that most manufacturers simply don't want to commit to any sort of figure.
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Old 10-23-2008, 12:21 PM   #6
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Quote:
Originally Posted by bob_ninja View Post
Did a quick search and the most often quoted number is 500 cycles.
Seems nobody wants to supply a more accurate figure. Batteries are affected by so many factors (temperature, load, SOC, etc) that most manufacturers simply don't want to commit to any sort of figure.
It is impossible on Lithium ion to quote a fixed number. Partial discharge recharges don't count the same as full discharge recharges, unlike some earlier technologies.

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Old 10-23-2008, 02:24 PM   #7
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Quite interesting comments. Actually I always had the idea that completely decharging and full charging was better. It appears what will be a more natural was of using it will also be better for the battery too.
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Old 10-23-2008, 02:35 PM   #8
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With old technology batteries (lead acid etc) it was beneficial and in fact required if you wanted long life to ensure they were discharged fully on a regular basis. (Not everytime obviously) Even now some technologies still benefit from deep discharge, eg Nicads. However Li Ion are different and my understanding (though I haven't had to look in depth at batteries for a number of years now) is that they do not benefit from regular full discharges.

Typical quotes for Li ion technology varies a lot but seems to end up around the 500 - 1000 cycles. I don't have a feel for Li ion yet, but I would expect that to be reasonable and hence around 2 - 3 years in a "typical" use. heavy use would shorten that.
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