123 Lithiums versus Ni-cad rechargeables

[geepondy]

I have been doing some initial comparisons of my Surefire 8AX which uses a rechargeable Nicad battery pack versus my E-2 which uses the 123's. It "seems" to me that rechargeable 8AX only holds it's peak brightness for just a few minutes before dimming a notch. The E-2 on the other hand seems to hold peak brightness for a longer period of time. Anybody every do comparisons of battery drain between the two battery technologies? I have not left either light on side by side, for any length of time as I have heard too many reports of lens damage. These lights are too expensive and precious for me to take a chance of that happening, particularly the E-2 which has the Lexan lens compared to the Pyrex (very nice by the way) lens of the 8AX.

 

[Size15's]

"Stop worrying about damaging your Lexan Lens!"

I've had the E2 on for 45 minutes, and the 8NX with Lexan Lens on for both batteries without any problems.
I've run more batteries than I care to remember through the 12PM, and both the C2 and G2 have been used continously at various stages.

I don't worry about damaging the Lexan, I worry about the cost of the DL123As!!!

One of the Advantages of the Lithium DL123As is that they hold their current output higher for longer - therefore maintaining the flashlight's peak output for longer.

NiCads don't to this very well, and therefore, I usually only get about 35-45 minutes constant on out of the 8NX before I swap to the fresh B90. This is also me wanting the very best output and I'm often willing to swap to new to avoid disappointment.

Al

 

[Brock]

As far as I know the time you have a problem is if you run the light in a small closed space (pocket, purse, luggage) or face down on a hard surface. So running them in free air the way you would normally use a flashlight is fine. If someone has melted a lens that way let us know. It is very cool to use them in the rain for extended times, they make the water steam off the light

Brock

 

[Spidey82]

so hoe long could U hold your E2 with bare hands before u, ouchh...

 

[Brock]

I have held mine for about 30 minutes during an inspection of a building restoration. The body of the light gets warm but not to hot to hold. The lamp end or bezel is to hot to hold, but I don't hold it that end anyway.

Brock

 

[**DONOTDELETE**]

There are two factors which govern the voltage (and thus the brightness of the lamp) during a battery's life.

First, the characteristics of the voltage drop over time. NiCds hold their voltage (after quickly dropping just a little from the freshly recharged state) fairly stable until just about discharged. This results in the familiar quick change from bright to discharged characteristic of NiCd batteries.
Alkalines and Li cells drop in a linear fashion, thus giving plenty of warning before they go dead.

Second, the characteristics of the voltage under heavy drain. NiCds will dim if the drain is very heavy. I once tried out the 3 C Mag Light with high cap Radio Shack batteries and a Carley KSR 1.7A lamp. The drain was too much for the C cells, and the flashlight was never very bright.

A 3 D cell Mag Light with Radio Shack hi cap batteries and the same KSR 1.7A lamp was much brighter, and lasted for about 90 min. The higher capacity of the D cell batteries enabled them to maintain a higher voltage during drain.

I suspect that Sure Fire flashlights are more governed by the first of these phenomena then the second.

Walt

 

[geepondy]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Size15s:

NiCads don't to this very well, and therefore, I usually only get about 35-45 minutes constant on out of the 8NX before I swap to the fresh B90. This is also me wanting the very best output and I'm often willing to swap to new to avoid disappointment.
Al<HR></BLOCKQUOTE>

I'm not getting that long out of mine. I've done a bit more testing with the 8AX and I'm getting no where near the stated 50 minutes of use. Turning on the light with a fully charged battery initially yields a beam that is slightly brighter then the E-2. This quickly dies down to a beam that is no more or slightly dimmer then that of the E-2, although wider. The total light output only lasts for 30-35 minutes tops and then quickly dies out altogether. If I let the batteries set for a little bit I can get another very short burst of light. So, IMO, the manufacturer's stated runtime is greatly exaggerated. I will however try this test on the second battery.

Although I haven't done a constant burn test on the E-2, it seems to hold truer to the manufacturer's run time specs.

 

[Tim Flanagan]

There WAS a bad batch of B90's not that long ago. A bunch of them cropped up in the early 8NX's but some might have made it to the 8AX's. It sounds to me like you might have received one of them. Every SF I've used over the years (tested or owned) has lived up to, or exceeded, the battery assumptions. Try the other battery- my guess is that you will fare better.

 

[Size15's]

Alastair will rant now. He can't help it!

Both the B90 Batteries that came with the 8NX I have each last for 50 minutes constant-on runtime. I've tested them both three times, and got quality light out of them right up to the end. Infact, some of the timings have exceeded 55 minutes before the light goes very pale and yellow.

Alastair (that's myself) is a real perfectionist, and demands only the best.

I will change the batteries in my 12PM after only 3 minutes. I will change the batteries when running the P61 after 10 minutes. I will swap to the MN20 when the MN21 begins to loose it's edge.

I will swap to a fresh B90 to maintain that initial high - even if it means only running the B90 for 20 minutes. After all, it can go back on charge.

I am a light junky. I love the amazing light of fresh batteries. I will "waste" my money by swapping the batteries early. Sometimes long before I need to.

It's the same with glass bottles of Coca Cola. I'll drink it for the just openned "high"...

In my experience of SureFires, their rated runtimes have always been very accurate. I don't usually run SureFires constantly. I don't often have the need.
Infact, when you use them "momentarily" which is one of the best ways, you can get far more than the stated runtime from them, and maintain the initial high of fresh batteries for longer.

Al

 

[geepondy]

Turns out the battery was not properly conditioned. It had only been charged once since receiving it in it's alleged fully charged state and then that was done before it completely discharged. Once it went thru another charge cycle, it performed much better. As stated by other people, it remains at very near constant brightness right up until the last five minutes. As a bonus, it also makes a great hand warmer. This might come in handy next winter. However I still only get a maxiumum of 45 minutes from either battery. Also for some reason, I would assume a higher voltage, one of the batteries runs the light just a tad brighter then the others.

What's the best way to use/charge the batteries? Should I let them fully discharge before recharging? Also, should I whip them off the charger immediately when the light turns green or would it benefit them further to let them trickle charge longer, say overnight, on the charger. And why not Li-ions rechargeables for the flashlight? They work great on my cell phone, lasting longer them the previous NIMH cell phone battery.

 

[**DONOTDELETE**]

NiCd batteries love to work, but not to loaf.

You should 'deep cycle' your NiCds every once in a while; this means completely discharging them, then fully charging them. This prevents a 'memory' from being developed, and the batteries only accepting a partial charge. Do not leave your batteries on the charger longer than overnight. Recharging partially discharged batteries is OK, so long as you deep cycle once in a while.

Li ion batteries are not more commonly used due to their much higher cost than NiMH or NiCds.

Walt

 

[JoeyL]

Hello!

Another reason Lithium ion batteries are not well suited for high amperage flashlights is their inherent nature. They are made for lower discharge rates, with that limit proportional to their size.

Lithium ion has the highest energy density of all the commercial rechargeables, at limited discharge rates. At high discharge rates, these batteries produce metallic lithium dendrites within the battery. These can cause an internal short, overheat, and become violently reactive.

This is why nearly every commercially available Li-Ion rechargeable has a microprocessor built in to cut the circuit for any discharge rate in excess of the safety margin. That's also why they are so danged expensive.

There is a new type called a lithium ion polymer battery with a plastic electrolyte which is inherently safer. However, none seem to be ready for market yet.

 

[Size15's]

Well then, use Li-Ion Polymer batteries then!

If the technology is young, then be the first!

It would be fantastic to have a Lithium-type rechargeable battery for the SureFire M6. A simple swap so there's not changes to the lamps - the batteries electronics could allow the M3 Bezel & Lamps to be used as well...

Alastair needs to work for a company such as AEA so he can make a battery pack as a pet project while he's there!

Al