I bought my first miners lamp powered by a lithium ion batter some 10 years ago.
I replaced it for normal use because it's contacts were rather poor. Never the less it keeps on working, my question is when do these batteries lose their life?

Appears to be about three years in a 'phone in daily use.
Scroll down to 'battery life'.

http://en.wikipedia.org/wiki/Lithium-ion_battery#Battery_life 

I would say its mainly charge/ discharge cycles with better quality cells lasting longer than JunkFire brands. Oldham will of course fit good quality cells and its reasonable to expect an extended lifespan.

A minimum of 500 full discharge and recharge cycles is reasonable to expect from good cells.

Obviously age will have a bearing on it, but older cells that are scrap though standing for a few years are more likely to have become damaged due to the voltage falling below the critical 2.6V.

Storage under poor conditions, such as near a heat source will also shorten life, best place to lay one up is in the fridge, same way we used to store camera film!

---

Phone batteries seem barely fit for purpose, God alone knows what they make them out of.

LIon batteries seem to last forever in lamps though. One of my Sten batteries has been in regular enough use since 2009 with no noticeable drop off.

It does make one wonder. I use Sanyo which are OEM, they are re-branded into a lot of the reputable makes and also used in a lot of laptops.

I bought a netbook computer SH of eBay about 3 years ago and batteries still going strong, I suspect good old Sanyo.
I think that its this brand Mr Bif uses in his lamps.

---

If your cells are well looked after then they will last for yonks.
Cells like to be Balance charged, use a "low" (0.5c) charging current, and must never be over-discharged. Chances are your charging system and/or lamp have various protections with regards to those issues built into it/them, and you will have a decent life out of them.

To expand on Roy's musings with OEM cells...

Brand wise, any of the bigger players will be fine in general use:- Samsung, Sanyo, Sony, Panasonic. Other brands are re-wrapped/re-branded versions of these. Some re-wraps/re-brands are just fine (Torchy, AWT, Efest), but then you get the utterly horrendous re-wraps/fakes from the dodgier characters (most things with "fire" in the name), and you have no idea what the history of the cell is... they re-wrapper certainly doesn't care if they have good capacity or are just waiting to flare. If your cells are from a reputable or known supplier, then they are probably good. They are not something I would take a chance with to save a couple of quid.

---

My interest now being hooked........
Anyone have precise tech info on the Oldham setups?

I am thinking of the answers to such questions as "is there protection circuitry in the power pack or is there over discharge protection in the headset and over charge protection in the charger?" (this latter is standard on Li Ion dedicated chargers anyway)

I remember reading some caution on some Oldham literature about overcharging, which suggests that the power packs contain only cells.

---

from personal experience of ultrafire 18650 batterys ,do not use this crap. if bought with their brand of charger they go on fire .very lucky i forgot my wallet one day ,or no more flat for me . :lol:

from personal experience of ultrafire 18650 batterys ,do not use this crap. if bought with their brand of charger they go on fire .very lucky i forgot my wallet one day ,or no more flat for me . :lol:

They not called "__Fire" for nothing!
:lol:

---

The Lithium ion battery I am referring to was an FX ion battery/lamp made by SPLEO TECHNICS. As far as I can see it seems to still have a good life. The main draw back was its poor connection to the Oldham type headpiece.
A few years ago, we replaced all of our lamps with new Oldhams, which again show no obvious deterioration. It seems to me that these batteries, if charged & discharged properly could have a very long life.
May be Simon could tell us if anyone has come back to him complaining that their cell has become defunct?
Interestingly Dyson, of cleaner fame, has put a multi million pound injection into a California company who are working on solid Lithium type batteries. They believe that these new developments will yield batteries which are even more powerfull for their weight.
Naturally Dyson has a vested interest!

Speleo Technics wound up when its owner retired, the quality of FX Ion will depend on the quality of the cells that were used, as described in postings above.
Unless someone has insider knowledge, its how long is a piece of string, sorry.

Thing is John, if you want to use it and unsure, why not just duration test it?

---

Thanks for the obvious Roy!
The point I was making is that other than small lithium ion cells, these batteries seem to have an extraordinary long life.
I was hoping that either you or Simon might be able tell us, if any of the miner's lamps you have supplied have needed a new battery?
When we all used lead/acid, Oldhams, I would reckon we would replace their batteries every 2 or 3 years, whereas these Lithium batteries just seem to keep going.

The point I was making is that other than small lithium ion cells, these batteries seem to have an extraordinary long life.
I was hoping that either you or Simon might be able tell us, if any of the miner's lamps you have supplied have needed a new battery?

Early lamps I supplied had some battery issues and were repaired or replaced. Apart from anything else they used "Trustfire" brand cells which were probably the best of the "Fire" Chinese brands. About two years ago I changed over to genuine Sanyo. Now I have covered these in my previous postings, and you have the answers you need there. I have not to date had a Sanyo cell fail but have only been building lamps with these for about 2 years. And, yes, there are still battery packs out these in use that use the Trustfire brand cells, what, 5 or 6 years old

When we all used lead/acid, Oldhams, I would reckon we would replace their batteries every 2 or 3 years, whereas these Lithium batteries just seem to keep going.

I once had a T2, remember those, that was probably years old when I bought it and turned out to be the best LA battery I ever had, still going strong when I gave it away.
Since then they went downhill with the last one, the T6 giving about 24 hours when new but going down faster than a hooker on Wall St.
People were replacing then after 9 or 12 months, they were abysmal with the damned Raylite or MF being total junk.
Thankfully LED lighting and Li Ion started to appear to save the day.
John, times change and technology moves forward.

By the way, be up at the Nent Easter if you around anywhere.

---

Back again
Quality cells, at least 500 discharge/ charge cycles.
One UG trip a week, 52 weeks in a year, 52 X 10 = 520 cycles
Store under cool conditions, never leave idle for long period and allow the protection electronics to overdischarge the cells, and there is your answer.
10 years or more.

Abuse, misuse, run flat and lay up in an oven for months and you junk it.

---

Roy, I think what we are stating is that with careful usuage these Lithium ion powered miner's/caving lamps will last a very long time, probably 10+ years.
There are still issues with larger cells, We have recently bought a 12 Volt one, which we intend to use to power a portable ultra violet light, it will be interesting to see how this gets on.
I think the issues with larger cells are associated with their possibility of catching fire.
At least two American aircraft freight carriers will not allow, large quantities of these cells to be freighted with them.
I did notice today that the Chinese owners of the firm making the 'black London taxi cab' is to set up a new factory,just outside Birmingham to make a Lithium powered/ hybrid version.
As you state,technology moves on.

Don't mix up Lithium Ion and Lithium Ion Polymer which are different chemistries. The LiPo are ones to be careful with.
To further complicate matters there are different Lithium Ion chemistries, Lithium Ion Phosphate being the one commonly used in 18650 cells (18 X 65 mm)

Interesting reading here:
http://en.wikipedia.org/wiki/Lithium-ion_battery 

---