Li-Ion/Polymer 3.6v batteries... your experiences?

[Jay-gon Jinn]

I don't have any Li-Ions that old yet, Nova...sorry, can't help you much....

[mihunai]

Havent used Li-Ions myself, but from what i read, the internal resistance increases over time, causing the battery to fail.

Maintaining a battery at low internal resistance is important, especially with digital devices that require high surge
current, as our printers do. Li-ion offers internal resistance characteristics that are between those of NiMH and
NiCd. Usage does not contribute much to the increase in resistance, but aging does. The typical life span of a Li-ion
battery is two to three years, whether it is used or not. Cool storage and keeping the battery in a partially charged
state when not in use retard the aging process.
The internal resistance of the Li-ion batteries cannot be improved with cycling. The cell oxidation, which causes
high resistance, is non-reversible. The ultimate cause of failure is high internal resistance. Energy may still be
present in the battery, but it can no longer be delivered due to poor conductivity.

http://www.extech.com/printers/resou...s/08212009.pdf

mTm

[Matt Thorn]

* BUMP? *

Dang. It figures. I ask ONE question of my own for once and all I get are crickets, hahahahahha :P

May the fourth be with you all... lol

I think any of us would leap at the opportunity to repay you for all the questions you've answered for us, but in this case, I'm thinking that since you were one of the earliest adopters, and probably put more strain on your batteries than the rest of us combined, no one else here is yet qualified to respond intelligently. I take it you asked because you are experiencing those symptoms with some of your oldest li-ion-powered sabers? A quick Google does not turn up much useful information, beyond scads of advice on prolonging li-ion battery life. How reliable that advice is anybody's guess, particularly since some of it is contradictory. Depending on the saber, replacing li-ions could be a major pain, but for someone like you, who can't afford to have a saber go funky on you at a bad time, I'd suggest biting the bullet and replacing those old li-ions with fresh ones. This bland advice brought to you by someone who has trouble even remembering which of his sabers are NiMHs and which are li-ions (and what the voltage of the li-ions in a given saber is).

[sithlordfaust]

It's actually pretty simple to make a charge-on-the-go pack. Get a "12V" charger for 7.4 Lithium Ion packs.. IE:

http://www.batteryspace.com/customiz...connector.aspx

Get a 14.4v NimH (Or Li-Ion, or even use an Alkaline 8-10 pack... or even a 12V sealed lead acid pack, your choice really) pack, such as:

http://www.batteryspace.com/nimhbatt...nimhcells.aspx

or http://www.batteryspace.com/customli...11pid4901.aspx

Gut the one, hook to the other and bingo... you are all set. Because you are powering the charger and not the other pack directly it should work like a charm. You should get about 1.5 to 2 charges of a 7.4v, 2600 mAH Li-Ion pack from it... more or less depending on the pack you get.

Note that charging voltage for a car is 14.4V, although the batteries are nominally "12V"... which means any charger designed to run from car voltage is generally good from about 11V-15V.

So... there ya go. Get a cheap wall charger for the 14.~V pack of choice and you are set to go for less than $150 bones.

Car charger might work like this, because like batteries, car chargers run on DC. Wall chargers however work on AC