T41: new spare battery care; conserving charge cycles?

[vwbmw]

My T41 is mostly used on AC, so its old battery (Apr 2004, 14.1wh capacity of 47.5wh, 311 cycle count, <30min) is just OK as reserve power. But I've just purchased a new Lenovo 'scratch&dent' battery as a spare, for off-AC use 'someday'. (Mfr Mar 2008, as-rec'd: 2.6wh of 54wh, cycle count=0) So I ask:

Q1:
Should I fully charge it at least once, or leave it as-is until I need it for true off-AC work? I've searched/read posts about charge cycles and the advice seems to be: store a battery at 50-80% charge, don't charge over 80%, and these batteries will deteriorate after about two years regardless of useage. Is that info correct?

Q2:
There is much advice about conserving battery life by setting charge thresholds (like 20%, 80%). My T41 has the current Battery Maxmizer and Power Management (ACPI) drivers, but I find no option to set charge thresholds. Is that not possible on a T41? ..the T41 will always/only charge to 100%?

Q3: If there is such a thing as undesirable 'shallow' recharges each counting as a 'charge cycle', what counts as a 'full' charge cycle? How best to accomplish the latter on a T41?

[yak]

Q2:
There is much advice about conserving battery life by setting charge thresholds (like 20%, 80%). My T41 has the current Battery Maxmizer and Power Management (ACPI) drivers, but I find no option to set charge thresholds. Is that not possible on a T41? ..the T41 will always/only charge to 100%?

Unfortunately setting the charge thresholds is possible only on T42 and newer models.

[aaa]

You can still store it at 50% and just use your old battery, then switch to and charge up your new battery whenever you go off AC.

[GACrabill]

Q1: Should I fully charge it at least once, or leave it as-is until I need it for true off-AC work? I've searched/read posts about charge cycles and the advice seems to be: store a battery at 50-80% charge, don't charge over 80%, and these batteries will deteriorate after about two years regardless of useage. Is that info correct?

A lot of folks won't agree with my answer but I plan on sticking with it. My T40 is almost always plugged in (at least 99.9% of the time). My original Sony Li-Ion battery from 09/2003 is still going very strong. It has a Cycle Count of 16, it's Design Capacity is 47.52 Wh, and it's Full Charge Capacity is 48.16 Wh. Whenever I do disconnect from AC for 10 - 15 minutes to show someone something, the battery life remaining will usually still be around 3:15 hours when I plug the AC back in (if I forget to lower the screen brightness a couple of notches, the time remaining has sometimes been around 2:50 hours. Think about it, that's 5.5 years on a battery that lots of folks claim are only good for 2 - 3 years. It has always seemed strange to me that there are so many different opinions (from experts) on how to treat a Li-Ion or NiMH battery (which are different, NiMH needs 'trained' and Li-Ion does not). I also think that the folks that do regular drain and charge cycles on Li-Ion batteries have been seriously misled by IBM and other battery salesmen. The main factor in Li-Ion battery longevity is minimizing cycle count. If you only charge to 50% - 80% and then store it, only to charge it again (another cycle count) .... then you are reducing it's life expectancy every time while getting no use from it. Incidently, I find it humorous when college kids pull their laptops out, use them for 30 - 60 minutes, and then put it away and repeat the process every day while only plugging it in when they have to .... then they complain that they have 200 - 300 cycle counts in a year and have to buy a new battery every year .... they just couldn't be bothered to spend an extra 10 seconds every time they turned on the laptop to plug it into AC (I guess Dad buys the batteries so who cares). If there's an AC outlet nearby .... use it.

If it were my new battery, I would charge it immediately to 100% .... never let a Li-Ion battery get to 0% if you can help it. I would put it in the laptop and use it and keep it on AC whenever possible. How much value is there in an old battery which only charges to 30% of it's original state -- not much.

When I get 8 or 9 years on my original battery, I will post my beliefs again.