what is the latest most reliable 18650 battery for 2012?

[DonK]

I'm not familiar with the home made chargers. I think I will go for the Panasonic based 3100 batteries, the 3400 models are about double the price, and I don't see a good reason to pay such a premium for a little more capacity. I store my batteries fully charged too - no point in doing otherwise IMO.

I note that soshine and 4Sevens do smart chargers at reasonable prices (I think smart is essential)

 

[Shadowww]

I store my batteries fully charged too - no point in doing otherwise IMO.

Well, if preserving battery's capacity and low internal resistance is pointless, then indeed storing them fully charged is way to go.
I prefer my batteries to lose 5% of capacity a year, though, and not 40%.. So I store mine at 50% charge.

 

[HKJ]

Well, if preserving battery's capacity and low internal resistance is pointless, then indeed storing them fully charged is way to go.
I prefer my batteries to lose 5% of capacity a year, though, and not 40%.. So I store mine at 50% charge.

You are living in a very hot place, at 25 degree you "only" loses 20% per year at fully charge (4% at 40% charge).

 

[march.brown]

You are living in a very hot place, at 25 degree you "only" loses 20% per year at fully charge (4% at 40% charge).

Hi Again HKJ ... My storage room for the spare batteries is on the North side of the house and doesn't get over about 20C ... Winter time it is probably about 15C in that room ... The torches with charged Li-Ions fitted are in assorted rooms that in Summer may well reach 25C for short periods of time.

It is only now after about three years that a few of my old Ultrafire 2400mAh cells are possibly giving trouble ... One died (no volts) and I was unable to revive it by coupling it to a good cell in an effort to (possibly) reset the protection ... That cell has now been disposed of ... Two (maybe three) cells go from 4.20V (approx) down to about 4.11V after resting for a few hours , the other few sink to only 4.18V ... These are all my original Ultrafires ... They are all still useable and even the worst ones still might possibly have a reasonable capacity left ... So I will have to do some battery run tests on one particular torch and make a note of the cell voltage against time ... That way I should know how the capacity of each battery will compare ... Any that are poor can then be safely disposed of.

I am gradually replacing the old Ultrafires with Panasonic 3100mAh protected cells ... I am assuming that they will last at least as long as my old Ultrafires have lasted ... Obviously I don't know how old the Ultrafires were when I bought them ... My Ultrafires don't get charged very often and since the Panasonics have a far larger capacity , they will be charged even less frequently ... Probably about four times each per year.

Since I will have only eight of the new cells , I don't think that it is worth changing my storage technique (or lack of) ... If I had loads of the new cells , then I most probably would store the spares at a lower state of charge and at a lower temperature ... I don't mind if the new cells last at least as long as the old Ultrafires ... I can live with replacing them after three years or so ... No problem.

I could keep the spare cells in the fridge ... It runs at a temperature of 3C ... I'm not certain how much better this would be for the fully charged cells or how long it would take to bring them up to room temperature ... If the fully charged cells were kept in the Fridge , how much improvement would there be on their capacity retention ?
.

 

[HKJ]

Hi Again HKJ ... My storage room for the spare batteries is on the North side of the house and doesn't get over about 20C ... Winter time it is probably about 15C in that room ... The torches with charged Li-Ions fitted are in assorted rooms that in Summer may well reach 25C for short periods of time.

My comment was mostly to shadowww, because you need an ambient of about 40 degree to loose 40% capacity in a year.
You temperature range is much better, you can check the table at battery university.

I could keep the spare cells in the fridge ... It runs at a temperature of 3C ... I'm not certain how much better this would be for the fully charged cells or how long it would take to bring them up to room temperature ... If the fully charged cells were kept in the Fridge , how much improvement would there be on their capacity retention ?
.

The capacity loss would be more like 6-8% per year (For a 40% charged battery 2-3% per year), but you have to watch for moisture, it might corrode the battery!

 

[anethema]

Yeah AW's cells ARE Panasonic NNP cells, with his protection circuit added in. He makes them right up to 3100mAh. http://industrial.panasonic.com/www-data/pdf2/ACA4000/ACA4000CE254.pdf

They are high quality cells and he makes a nice protection circuit. In multi-cell lights, not having a protection circuit with ICR chemistry is a bit scary IMO.