Will M*g 3D melt by using WA01185?

[_mike_]

There is a groupbuy going on, probably too late to get in on that, but you can always ask litho123 if he might have any extras. If that doesn't work, put something in the B/S/T ... something like:

WTB potted WA1185 bulbs (or whatever bulb/bulbs or other parts your interested in).

And see if anyone responds.

 

[Ginseng]

sjackal,
I couldn't find that charger you're talking about but if it has independent channels and -delta V charger termination it should work fine. That is, if it's an "intelligent" or "smart" charger.

s2k,
I'm afraid there really is no good retail outlet for the flashlight-type bulbs from Welch Allyn. It really comes down to group buys. If Flashlightlens.com still stocks the WA01111 and WA01160 bulbs for the MagCharger, perhaps they could be convinced to stock a few WA01185. Only Carley does custom potting as a matter of course.

Wilkey

 

[_mike_]

Unfortunately I received an e-mail back from Flashlightlens.com. They only carry the WA1160 for the MagCharger. /ubbthreads/images/graemlins/frown.gif

 

[SJACKAL]

Can I ask the masters if Gold Peak's 2100mah AA Nimh is a good idea? I found a 30 min GP charger which they come in together.

http://www.gpbattery.com/Primary_batteries_Rechargeable.htm

 

[js]

sjackal,

You'd really have to examine the discharge curve (voltage vs. time) of these batteries at your current draw. If the mid-point voltage (MPV) is 1.1 volts or better, you're safe in using them. I'd stick with Wilkey's recommendation: tried and true. No need to reinvent the wheel. But I'll defer to Wilkey's advice regarding these AA's.

 

[Ginseng]

If the discharge graph shows a curve for 3A or 1.5C (doubtful, I'm afraid) then you can get some idea how they'll perform. Unfortunately, I don't suspect many consumer grade cells publish data at this discharge rate.

Can you locate a datasheet for your cell of interest?

Wilkey

 

[Nerd]

GP2100 mah battery data sheet (PDF)

At 2 amps of current draw, the 2100 is suppose to last 1 hour. At 4 amps, around 27 mins, at 6 amps, slightly less than 20 mins. Let's take the 4 amps discharge curve. It starts dropping steeply at the 20 mins point. So I guess you'll get usable brightness for 20 mins?

 

[Ginseng]

Hi Nerd,

That little cell seems to be pretty robust. At 3.1-3.2A, it looks like it should deliver 40 minutes of decent runtime at 1.15V/cell at 50% depletion. Damn, that 's pretty good. But then it's from their HC line. I assume that to be "high current" capable. I also see that it can withstand one year at 0.1C trickle. Again, amazing. Internal resistance is a bit higher than typical HC cells (3-6mO) but not bad at all.

Dang, where can I get some of these babies?

Wilkey

 

[paulr]

How do you actually put a WA01185 into a Mag 3D? Do you have to get it potted in a PR base? Is there some mod to change the 3D bulb holder to bi-pin? Or does the '85 use some other base?

 

[Ginseng]

There is no suitable commercial bipin to PR adapter for this current range. The bulb must be potted and Carley is usually the go-to company.

Wilkey

 

[Nerd]

Hi Wilkey, actually those are "High Capacity" Cells. I never realise that they can take high current of up to 6 amps either. But if you're comparing Sanyo 2100mah and GP 2100mah, according to Sanyo's datasheet, their own 2100 cell has 25 milliohms of I.R while the GP 2100 cell has 18 milliohms... food for thought...

 

[Ginseng]

Thanks for that info. It's great to learn something new. So far, the MAHA cells have been my reference standard in AA but these GPs have me thinking again. The Sanyo's are very good as well.

Wilkey

 

[SJACKAL]

So the GP 2100s are suitable for the Mag85? If so I am going to buy them now! They are on offer alongside with their 30 min charger.

 

[SJACKAL]

If the GP2100 are high current capable, with IR lower than the Sanyos, I wonder about their 2300 line? /ubbthreads/images/graemlins/naughty.gif which will last a bit longer, but at higher IR (still lower than the Sanyo 2100 on average).
http://www.gpbatteries.com.hk/pic/GP230AAHC_DS.PDF

 

[Ginseng]

sjackal,
It's worth a try. The 2300 gives up some voltage (looks like 0.02-0.03V/cell at that load at 50%) and actually a little lower runtime I think. But still, quite impressive. Please let us know how it works out. I wouldn't mid testing these head to head against the Sanyos or MAHAs.

Wilkey

 

[SJACKAL]

Ok, but its still awaiting for the bulbs and a longer wait for the reflectors, but I will get the rechargeables soon.

 

[Ginseng]

Jack,

Did you check out Fivemega's sale of cammed reflectors in the GB forum? I am familiar with his work first hand and he does good stuff. You might get one of his quicker than the Carley. And when the Carley does come in, you can sell it.

Wilkey

 

[SJACKAL]

I need to wait for the bulbs anyway... And he mentioned that people already in Litho's GB should stick to it... I will think about it.

 

[SJACKAL]

BTW you think 1185 will work with 8 GP2100 Nimh with Fivemega's 8AA to 2D battery adapter?

 

[Ginseng]

Yes. It will not be at its ultimate but will still be crazy bright. It'll be underdriven before 50% depletion, however. I would not run it to significant dimming.

Wilkey