Battery and Lamp Performance Table

[darkplaces]

Bored one night I thought I would collect some information together about differanrt batterys and builbs/Leds and the performace, ie how long they last giving usefull light. So far the builk is from the manufactures and I am trying to ensure the source of the information can be tracked.

Written in Excel - An Excel viewer can be found on the Microsoft Windows Website.

Please if you have any more information or wish to update, correct or confirm information please let me know by posting here, thanks. If you have a Lamp and your pleased with it and it doesnt appear please post me the battery used its voltage, capacity and builbs used as much information as you can.

ftp://ftp.c**tplaces.co.uk/pub/media/documents/battery_lamp_performance.xls
Size: 41.0 KB - Updated 20th Feb 2006

A html Version can be found here but check the last update time;
ftp://ftp.c**tplaces.co.uk/pub/media/documents/battery_lamp_performance.htm

 

[potholer]

Having an idea of the information source sounds like an excellent idea.

I think it's the more recent NiCd Headlite battery that's 3Ah - the previous one was 2Ah
(In http://www.speleo.co.uk/images/headmk2.pdf , it refers to the MkII having 50% more capacity than the MkI)

The nominal voltage of an FX2 is 2.4V. The *bulb* might be rated as 2.8V/0.85A, but would be being under-run much of the time, for extended life at the expense of efficiency.


According to the data available on the Farnell website, Duracell Procell AAs are rated at 2700mAh, and Duracell Ultra M3 AAs at 2900mAh. According to data on the RS site, Regular Duracell Plus cells are rated at 2850mAh but that's for discharge to 0.8V/cell, and at a slow rate.
Other brands seem to be in the same ball-park - 2600mAh or above.

Given how close the figures are, and how unlikely the theoretical capacity is to be realised except when running at low power (less than 0.1W/cell), it probably doesn't matter precisely what figure is put down - 2700 might be easiest, since it's conveniently half the figure for a 4.5V pack, and fairly easy to remember.


I know it would make things more complicated, but it might be worth adding some footnotes indicating what a lifetime is meant to mean in the case of LED lights. In the case of the Nova3, Speleotechnics state they pick an endpoint where the light is still quite usable, and that the Nova3 doesn't run as brightly on Alkalines as on rechargeables - the '3W' and '1.5W' tags aren't really applicable to low and high power off alkalines, or at least, not for any significant time even with fresh batteries.

A link to http://www.speleo.co.uk/images/LED%20discharge.pdf could be interesting. For reference, the starting brightness of 25lm is *roughly* 0.85W with an LED of typical efficiency, or a little less with a more efficient one. The 2 lumen cutoff approximates to 1/15 of a watt of consumption.
I'm not sure what the 'other light' they are comparing with is, but I'd guess it might be an Apex. To be fair, the other lamp is using batteries with half the grunt, so the curves are roughly comparable when that's taken into account, though the comment about the cutoff point for the runtime figures for the 'other light' being overgenerous would still stand.

 

[darkplaces]

Brilliant, thanks. I'll have to spend some time merging all that into the spreadsheet, the best format I think. I wont make it too complex, as you say lots of variables means run times cant be down to the minute.

The reason for its creation, I spent a lot of time trying to figure out the best lamp to use and it was a pain having to keep looking up run times on websites. I liked the Novas because of the battery flexability, the ability to use your old battery systems making it infact cheaper then a full lamp & battery system replacement. Shame they didnt support the FX5 though as a recent one from mineexplorer.org.uk now does which supports a wider range of battery types ((1)2-7v). As long as the output is better then the old this should (in theory) be a winner.

Worth a look! - http://www.mineexplorer.org.uk/ledlighting.htm

A very worthwhile input from cavers/mine explorers would be real world lamp lifetimes of useable light, I know this will be subjective but a high number of samples with the mean taken should give a real life idea.

 

[darkplaces]

Updated my document, anyone got any run times are various battery combinations to submit?

Ta..

The document is totally copyright free.

I'll add that i think.