Prolonging the lives rechargable Lithium Ion cells

[koala]

A good read at
Prolonging the Lives of Rechargeable Lithium-Ion Cells

[ QUOTE ]
If the discharge cutoff voltage were raised to 3.5 V, the consequent loss of capacity would be only 10 mA·h, while the cycle life would be extended.

[/ QUOTE ]

Sounds interesting but how much life extended is not given. Will you sacrifice that 10mAh for the sake of longer lifespan? With rechargable LiIon flooding the market I don't think prolonging the life of a battery/cell is critical, perhaps this only apply to low maintance situation. However, I would sacrifice that 10ma /ubbthreads/images/graemlins/smile.gif for a longer lifespan if it's true.

Vince.

 

[James S]

I agree in a situation where you can get the batteries cheap it's not probably that big a deal and I'd want the option of having my flashlight run a little longer in survival situations.

However, in something like a laptop battery where a replacement still costs over $100 even with the price of every other LiIon batt dropping an extension in life that cuts the battery time by 5 minutes and yet lets you use the same battery for an extra month or longer before having to replace it would be a big deal!

I am waiting for LiIon batts to really hit the mainstream, as currently packaged it is my personal opinion that they are WAY overpriced in most battery packs... Course, by the time that happens the laptop folks will have moved on to even more exotic batteries that will cost that much or more again. You can't win /ubbthreads/images/graemlins/wink.gif

 

[koala]

James, I agree with what you said. I didn't think of laptop battery in the first place. They are costly. Fuelcells is coming /ubbthreads/images/graemlins/smile.gif

Vince.

 

[highlandsun]

Re: Prolonging the lives rechargable Lithium Ion c

Overpriced is right. Sony's list price is still $249.99 on most of their laptop batteries, and the raw cells in quantities they use are only $~1-2 each. Nuts... I've started buying dead LiIon packs off eBay for $3-5 each and replacing the cells, so now I have spare packs for both of my Vaios, all for less than the cost of one new pack.

 

[Unicorn]

Re: Prolonging the lives rechargable Lithium Ion c

I think that some of the cost in the battery packs is the charging cutoffs. So that when a cheaper charger, that doesn't stop charging the battery when it is full is used, it won't cause damage to the pack.

 

[James S]

Re: Prolonging the lives rechargable Lithium Ion c

highlandsun, but where do you get the bare cells to replace in the packs? I've got several that I'd like to rebuild but I can't get the cells anywhere I've looked unless I have some kind of license to manufacture the cell packs and buy in huge quantities.

I would love to get a few dozen to rebuild a couple of packs, but I don't need a thousand of them /ubbthreads/images/graemlins/smile.gif

 

[koala]

Re: Prolonging the lives rechargable Lithium Ion c

Buy it from Slavin4u.com. The price is abit higher but it's located in the USA.
Or you can try this Malaysian company Sabah Oceanic, user N162E has experience ordering from them here US18650GR Availability.
If all else fails, you can beg /ubbthreads/images/graemlins/bowdown.gif /ubbthreads/images/graemlins/naughty.gif highlandsun to start another round of groupbuy like he did last time. /ubbthreads/images/graemlins/thumbsup.gif /ubbthreads/images/graemlins/thumbsup.gif /ubbthreads/images/graemlins/thumbsup.gif

I have luck with camera battery packs. I disassemble them and repack them. Must beware though, the casing shape does not always means same shape cells. Some cheap inferior rounded edge casing are packed with prismatic cells instead of cyclindrical cells. Also, I once took apart a battery pack which says 720ma, but endedup with 650ma cells inside, printed clearly on the cells heatshrink.

Vince.

 

[James S]

Re: Prolonging the lives rechargable Lithium Ion c

LOL, now that you mention it I think I DO remember highlandsun doing that, but I was terribly broke at the time and couldn't do it...

I'll have a look at the others, thanks!
James