[TriLUG] Thinkpad Batter\(y\|ies\)

Joseph Mack NA3T jmack at wm7d.net
Thu Jul 1 21:44:20 EDT 2010

On Thu, 1 Jul 2010, Joel James Adamson wrote:

> Hello,
> A while ago I bought a Thinkpad 240

this is the little one? I have 3 of them. Provided they have 
enough memory not to swap when you load a webpage, they're 
great for travel. Unfortunately with the smaller kbd and the 
different key layout, I have trouble going between it and my 
other machines. Still it can't be beat for travel.

> Knowing nothing about laptops (this is my first), I'm 
> unsure of the "gotchas" of buying a battery online.

First you need to know about batteries. Look on google for 
"Li ion battery life". (I did find a place in Canada that 
builds/tests/repairs (forget which) batteries and has a 
whole heap of stuff about batteries, but I can't find it 

The wikipedia page is a good start

o batteries don't like heat (I don't know how you can get 
around this - when your laptop is on, it's hot. I guess you 
shouldn't leave your laptop in the car during the day in 
summer). I have some 10 yr old laptops that have been inside 
the house all the time and they still work fine (I don't use 
them a whole lot - they're too slow).

o at 100% charge, batteries loose 20% capacity/year. At 40% 
charge they loose 2% a year (this is what Priuses and 
solar/battery powered satellites rely on for battery life).

o batteries sitting on shelves loose capacity. Don't take 
old stock. Presumably you want a store that holds a small 
inventory and inserts batteries into cases almost on demand. 
However I can't imagine anyone making up new 240 battery 
packs anymore, so I expect yours will have sat on the shelf 
for a while.

o expect a battery to last about 2 yrs.

o batteries are expensive and don't last long. Buy the 
smallest number of batteries that you can live with.

o In your case get the extended battery. The regular is just 
too small.

Here's who I bought my last 240 battery from (Dec 2006).
I haven't used the laptop for 2 yrs so I can't really tell 
you how long the battery lasted. However I checked the three 
240s earlier this yaer and they all had charge.

ebay, PAYPAL *SUNNBATTERY, ebcbattery, thinkpad 240, 
3400mAH, FRU 02K6690 904-338-9619, 
customerservice at ebcbattery.com, $28.95+$10.95 S&H

> 1) Are there any especially good (in any way) online vendors?

I've bought all over the place, in the early days not having 
much of a clue what I was doing and without really being 
able to tell how much capacity I should have and how much I 
did have. I never got burned - I always got a usable 
battery. Much of by batteries were from ebay. However I 
found that the ebay 12V 7AH Pb batteries for UPSs lasted 
about a year, while the equivalent batteries from Batteries 
Plus (stores all over the place locally) last 2 yrs.

Except that Batteries Plus are more expensive than ebay, 
they're better and the people are helpful. I buy all my UPS 
batteries from Batteries Plus now.

Still if I had the choice of a laptop battery for $75 off 
ebay and $150 from Batteries Plus I'd probably go with ebay.

I avoid buying batteries for laptops as I find that I want 
to upgrade about when the battery is dead (I buy 5yr old 
laptops for $200-400 and the battery cost is almost as much 
as the replacement laptop). I try to stay close to power 
plugs all the time (I carry a 3 way T-power adapter, so I 
can plug into the wall when someone already has their laptop 
plugged in).

Airports are terrible for getting power. I don't know where 
they plug the vacuum cleaners in etc.

> 2) Is there anywhere locally I could buy one?  They don't 
> have anything compatible at the campus store

a 240 battery is a specialised item. Even Batteries Plus 
would have to order it.

> 3) Anything to watch out for?  I noticed one vendor offers 
> a compatible battery for $19.95 labelled with 
> "refurbished"

I expect it's an old battery pack with the dead cell(s) 
replaced and the half alive ones still in there. Don't touch 
it. All cells must be brand new.


Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
generator at http://www.wm7d.net/azproj.shtml
Homepage http://www.austintek.com/ It's GNU/Linux!

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