[General Topics] LGB:
I have a laptop and a phone, both using original batteries and both around 4 years old now. The laptop is a dell with a 7 aH Li-Ion battery and the phone is a Nokia 6310i with a factory Li-Polymer battery. As I said, original standard batteries that came in the original package. Both have only been used with company standard chargers - no quick force-feed cradles here.

If I start with the phone, it is one of the best I ever had. I don't make many calls on this phone, mainly text messages, and it spends the most of it's time just idling. At night I usually turn it off, sometimes I use the temporary profile option with tone/vibration off, as I sleep better knowing the phone will not wake me up. I had a collegue who bought the same type of phone as me, and we treated it way different. First of all, he used it a lot more. Second of all, the charger went in and out quite often, and he often used the phone while it was charging. I have consistently only charged this phone to 100%, usually overnight. Sometimes charging it when it was quite low, but most of the time after about a week. This phone last two weeks on standby (if used during daytime only), and after 4 years ... it still does! It was the first triband Nokia made (to my knowledge), and I got one of the first ones in stead of getting the third Ericsson T39m in the same year (kept failing!). My collegues phone did not even last a day on a full charge, in LESS THAN HALF A YEAR. Now, four years after, my phone still last me two weeks with the minor use I demand of it.

Most notable habits for handling the phone/battery:

Very seldom used during recharging

Almost always charged uninterrupted to 100% - in off position or without using it

Not so heavy use

My collegue on the other hand interrupted the charge before reaching 100%, used it while on the charger and his battery died down to almost no capacity sooooo fast.

As for my Laptop, it is a Dell Inspiron 8600, and after 4 years, it still runs almost two hours on the original battery, using internet, wireless and bluetooth simultaneously and not going into any kind of power save.

Below is the way I have generally used it:

I have seldom removed the battery while on mains, as I find it difficult and also enjoy the safety of the battery being there if I pull the chord, power outtage etc. Contrary to my phone, I use my laptop A LOT, like, daily, for many hours usually, sometimes all day. It is mainly work related, reading/writing documents, some graphic work and so on. Not so much watching movies, but sometimes certain programs like OCR or other runs keep the CPU to 100% for a while. I mainly keep the battery in and charged, and unless the ambient temperature is high or I sit with the laptop on top of my lap where my body heat heats the battery, I have not found the battery to heat up much. Even when the fan is going 100% on a heavy load, the battery temp seems OK. For various practical reasons, I have more often recently used my laptop on battery until just before it cuts out by itself. I must say I did not check if that makes the battery hot, but after 4 years, I still get almost two hours of use with wireless and bluetooth enabled. I have friends and collegues who replace the battery after one or two years, because it is down to almost nothing in capacity.

Any battery powered device I have had in the last 5 years or so I have been treating with these golden rules, and none of them have had to have batteries changed so far ...

Do not interrupt battery until it is done charging (unless on trickle charge, obviously)

Charge any time you like, as long as you obey the rule above

Do not place a heavy load on the device while it is charging after having been run on batteries (again, trickle charge is OK while on mains)

A good way to accomplish these rules is to have a habit of charging devices before you sleep, even before being worn down (charging not so likely to be interupted by sudden change of plans).

Having run my laptop for thousands of hours with battery inside and connected to mains, for me after 4 years it has not killed my battery.

This is not scientific research, but for me, it has worked for all my devices - for whatever reason. Those who complain their batteries die quickly seem to be the ones who pulls the charger whenever they want.

Although lithium batteries are somewhat different than the way humans store and use their energy, it seems to me there are some similarities:

Does not like it too hot or too cold

If not allowed to eat/charge fully on a regular basis, charging more often is necessary.

Can get annoyed if suddenly disrupted during feeding/charging.

If force fed, less energy can be taken up compared to a slow and easy feed.

This is not meant as proof, as in "because humans are like this, so are batteries", but to me, it just seems coincidental that there are some similarities. Me, personally, I eat one to three times a day. Yes, I can do with one meal a day, but two meals a day I think are optimum for me. Consistently eating 3 or more times a day makes my weight go up, I have been over 200 pounds for my 6'3" after being in a job for a year where I "was fed" too often. Now, I am fit and healthy at around 170 lbs, I seldom have headaches or fatigue, and I have an endurance like not many others! Without "charging" I can last a long time. Give me a good evening meal, and the next morning I can run a half marathon with no breakfast, just water.

Conclusion: Let the facts of real life be your proof instead of going after experts opinion. Let's have more experiments to find the real truth!