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

[Joseph Mack NA3T]

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 
tonight).

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.

Joe

-- 
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
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