Spare Battery care & feeding

I have an M1210 with a spare battery. What is the best way to care for the batteries? I have one extended battery and one lightweight battery-- I'd prefer to keep the extended's life preserved for as long as possible for use when travelling.

Should I:

1. Keep the extended battery unplugged and store it?
2. Rotate the batteries for roughly even use?
3. Keep the small battery unplugged and store it?

And if I should store one of them, should it be stored charged or uncharged?

 

First I would like to say that the M1210 is a sharp looking piece of equipment. I hope it works out well for you. I had the same question a few months back and my son the computer major made it clear that all lithium batteries that are not in use should be drained of charge or to the lowest level possible then stored. This can be accomplished by using the battery if it already does have a charge. Best storage for any electronic component is an anti static bag that you could possibly find as a freebie at a local computer store. I suppose you can alternate like you mentioned but personally I like knowing I have a new ready to use full charge capability ready battery any time my other decides to take the nose dive. Of course if you travel for work or play it will never hurt to charge the alternate battery up and use as needed. Most important thing is to keep at it stored with the lowest level charge possible, it will drain completly in time. The worse thing you can do is to charge the battery to full or near full and let it drain on it's own. Hope this helps. Now I am going to go find away to drain my Lithium Ion power tool batteries I have not been using and take my own suggestion. Hope this helps.

 

Supposedly draining it to 40% charge and storing it in a cool, dry place is best. I have mine out of my laptop right now sitting on my shelf. If I knew a ziplock bag would do a good job of blocking condensation, it'd be in my dorm fridge.

 

it seems the general consensus is to take it to 40% and then keep it in the fridge.

i, however, have 2 batteries, and simply rotate them about every week or two. i got the notebook in march'05 and i still get incredible life out of both of them. the 9 cel still gives me 5+ hours and would give me almost exactly 6:00 when new.

 

Digging around on the web seems to back up what ajfink is saying. Storage should be as cool as possible, and at approximately 40% charge rather than fully drained. I'm going to keep looking around.

If anybody's got any Dell-specific and authoritative info, that would be highly appreciated, too.

 

The higher the temperature the batteries are exposed to, the more quickly they will lose capacity. This is apparently true even if you do not charge and discharge them. So, it seems the worst place I can store my big extended battery is in the laptop, where it will be both hot *and* getting used.

I'll keep the little one in the laptop most of the time, and pull the big guy out of the fridge for travelling as necessary.

 

Oops.... looks like I was wrong

This site tells all about battery storage

 

http://forum.notebookreview.com/showthread.php?t=77046

 

drumfu makes a great point about his own use and experience. When you purchase a new battery it has no charge or very little charge. There is a reason for this. Any battery manufacture can let you know what is ideal. I suppose 40% is just as good as 30% or 50%. Makes you wonder why new batteries have little or no charge in them when first purchased? Simply because Lithium-ion based batteries should be stored with as little or no charge as possible when new. Cool and dry storage is always a good idea. Now the common consensus of the loyal forum readers and Internet researchers that say 40% is the common belief that research has provided is only for newer batteries in use and are capable of holding the full charge. As a battery wears it will hold less charge resulting in less the sliding percentage depending on the wear of the battery. So Yes 40% is fine however only for batteries that are capable to holding the full charge they carried when they were new. Ultimately there is a percentage for each stage of wear of Lithium-ion battery and that is why I recommend keeping the battery the way the manufacturer stores them prior to shipment. Below please find the research mentioned in this forum plus more then anyone could ever want to know about the Lithium-ion battery.
http://www.batteryuniversity.com/parttwo-34.htm To contradict myself I will also provide a link that says to keep your battery charged and recharged on a regular basis. However remember the battery will wear when used. http://www.batteryuniversity.com/partone-21.htm Have fun and check out the tabs on the site until you know more about batteries then you ever wanted to.

 

Yep I agree. Thanks raygundan.

 

Because of the way the charging circuitry in a Lithium-Ion battery works, if the charge level drops below a certain critical point, it will refuse to charge, and at that point the battery is useless.

A stored battery does loose charge over time to leakage, so if you store a battery with little or no charge for long periods of time, there is a chance that it will drop below the level at which the charging circuitry will allow it to be charged again...

Hence the 40%.... You shouldn't store with little to no charge.

 

I am so glad the links I provided in an earlier post have been read. I would just like to add that lower temperatures also assist in prolonging the life of a battery. (Just never freeze)