Peripherals: how to prolong a Li-ion battery's life?

(NT) A nod to battery university...

by R. Proffitt  - 7/22/05 4:46 AM

Li-ion Batteries

I worked for a cell phone company for 8 years and did a lot of research on this subject so I could properly inform my customers. There are basically 3 types of chemicals currently being used for cell phone and laptop batteries. Ni-cad, Ni-mh and Li-ion. There is a fourth makineg its way in Li-ion polymer. A couple things are consistent for all types of batteries no matter what chemical is inside. You must initially give the battery a 12-14 hour charge on the home charger. (Don't use a cigarette adapter for the first charge. This conditions the battery and don't take it off the charger that first time even if the charging indicator says it's full after 3 hours. Also the manufacturer's also state to run it thru 3 charge cycles. What that mean's is that you fully charge and fully drain 3 times. 1 full charge + 1 full drain = 1 charge cycle. Here's where the way you charge the battery starts to differ.

Ni-cad: Mostly only on older devices, has a "memory" effect, should be drained before a full charge is put on it, should be removed after overnight charge or can be overcharged and burnt out.

Ni-mh: Still used for some devices, has slight memory effect but not enough to have to fully drain before the recharge, should not be consistently left on charger after full charge that can eventually burn out battery and shorten usage time.

Li-ion and Li-ion polymer: Used on a lot of newer devices, has no "memory" effect, should be recharged as often as possible, actually likes to be charged and draining it regularly can cause the usage time to be shortened, can NEVER be overcharged so whenever you're near a charger put it on there. Besides those benefits a li-ion battery is lighter and smaller but the chemical can hold more charge than Ni-cad and Ni-mh.

So the one reply to your question said to error on the side of draining the li-ion batteries. This is incorrect information. You want to charge the battery before it gets below a 20% charge. Also batteries will not go bad from accidentally doing the incorrect charging procedure here and there but normally follow the correct procedure. One last note try to use the home charger more often than the cigarette lighter charger for best long term results. Cigarette lighter chargers do not give a full charge (about 95%) which in the long run can damage any type of battery listed.

Hope this helps

P.S. Every battery will have those abbreviations to tell you what cehmical is inside the battery, even rechargable power tools which these charging procedures apply to also.

Charging Li-ion mobioes

I'm hoping you will be so good as to give me some advice on charging Li-ion mobile batteries.
We supply a means for poor people to have a little electricity far from the mains.

One application is solar charging of mobile phones but this is causing problems with the new Li-ion batteries
now coming into use. For reasons that still puzzle, most phones do not accept our solar charging.

If the battery is removed from the phone to be charged it's okay.
But when inside the phone there is no charging unless the current is over 300mA - which is more than our small panels provide.

I have solar charged Li-ions outside the phone many times with no problems but most clients are understandably doubtful about this!
What is your opinion?

I suspect it comes into the same category as manufacturers who warn against charging dry cells. It's not on their interest to encourage it!

Grateful for any assistance!

Sincerely


Graham Knight
BioDesign (non-profit)

Rechargeable Batteries

All rechareable batteries have a finite number of recharge cycles, after which they no longer hold their charge. (The technology only defines the availabe amp/hours/volume.) Anything you can do to reduce the number of recharges will extend the battery life. So your saleman was close: Wait till the battery is (almost) discharged, and then give the battery a full recharge.

consult the manual or manufacturer

Some cell phone manuals will inclue this info of how to best prolong your phone's Li-ion battery. If not, try calling your phone and/or battery manufacturer for this info on their suggestions.

NOTE: li-ion batteries don't necessarily follow one global rules. E.g. for some stand alone PDAs, it's best to top of li-ion rechargeable batteries. For cell phones, the manual will tell u best to discharge the power as empty as possible before recharging

prolonging lithium-ion batteries

My digital camera which also uses the li-ion battery says in the manual not to charge it and leave it charged when not being used in order to prolong the battery life. They do better being discharged and stored. Now, of course, one wants a charged battery on a phone so I would suggest that there are limited cycles of charging and discharging. They do not have a memory so it is not necessary to run the battery into the ground but does it hurt it to do so though when you are half off a cliff teetering in balance in your SUV, it would be nicer if that battery were fully charge...right? Just charge away and buy a battery once every few years. Most likely the phone will crap out anyway and the batteries are not yet a standard design.