lithiun vs nimh?

[**DONOTDELETE**]

glad see forum up and running!!!!
had problems last few days, web tv?
found energizer lithiums at wal-mart 4 aa's @ 10.50 vs rayovac 4aa's at same price. figured i'd go with nimh for around the house use in brinkmann. noticed the package said charge before use but as a test dropped a par right into brinkmann and it lit up as bright as the eveready that came with it, confirming that this light will work with the weakest batteries?(

i have been using nicads in radios etc for years and am curious how much longer the nimh's will last. gonna drop a freshly charged pair in brinkmann and run till i see a reduction in light output. that's the beauty of leds, i wont need to stock up on regular bulbs!!!! also gonna try them in portable cd player.
an earlier post suggested lithium batteries in brinkmann for longevity, and i,ll probably buy a few sets of those too! hey, one can never have enough batteries!!!!! (

ps. now if mr johnson will ever conclude his tests of the "wal-mart flashlight"???????
also found eveready arc white at wallymart for 16.26, next trip there =aa lithium 4-pack and arc white(

 

[RonM]

NiMH AA batts have are generally rated in the 1200-1600mAH range, depending on which you buy.

The danger of using them in a flashlight is that you will destroy the battery if you fully discharge it (I know from experience). NiMH batts are better used in electronic devices which shut themselves off when the voltage gets too low. Additionally, NiMH's have a pretty high self discharge rate. I think about 1% per day. This also makes them a bad choice for a flashlight which may sit around for a long time between uses.

Stick with alkaline or lithium. The LED lights use so little power that you won't be breaking the bank on batteries anyway.

Hope that helps.
RonM

 

[**DONOTDELETE**]

I'm not familiar with the chemistry but I can advise you not to assume a flashlight uses fancy circuitry to boost voltage just because it lights with a supposedly 'dead' battery...even a filament bulb, in a Sure-fire say for example, will light very brightly for a few seconds (then dim down to nothing) when previously 'dead' lithium batteries are allowed to rest for a while (so you must keep them in there since they're still useful, right??)...you may be getting the same effect from the nimh batteries -- I know they operate at a higher voltage (1.7) than alkalines, and freshly charged ones may have melted my 6 volt 4cluster leds in my (4aa)Quantum...

 

[**DONOTDELETE**]

thanks for info, i was surprised to find the led glowing very dim after 7 hours, not sure how long it was dim as it sat in a drawer. after turning it off for a few secs, it lit up brighter for a few more secs. the nimh's were on charge for 5 hrs. hope i didn,t damage them, they,re back on charge. which brings another ? do nimh need a special charger?
i'm using panasonic model bq- 8c, designed for ni-cads. is this one okay for nimh? anyway tried a pair of nicads in brinkmann and it ran 11 hours and was still a bit brighter than after 7 hrs on nimh. also 1% daily loss isn't that bad compared to nicads 2% which i read. the rayovac nimh's are rated as 1.2 volts, 1300 mah. is this bad for power boost circuitry in brinkmann? i keep plenty of duracell alkalines on hand but have been thinking of the savings using nicad/nimh as i plan on using the light a lot in the yard come spring, summer. my 7 year old daughter thinks led flashlights are "wow cool dad" ) actually i have 3 brinkmann lights, 1 in car 2 in house, at 12$ i couldn't resist! i'm planning on a better light, eternal lights look really nice. that'll probably be what i get next, and who knows from there!
happily addicted )
thanks

 

[The_LED_Museum]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by franken:
do nimh need a special charger?
i'm using panasonic model bq- 8c, designed for ni-cads. is this one okay for nimh? <HR></BLOCKQUOTE>

If you value your batteries, you should get a charger meant for them.

Best suggestion: Radio Shack Cat # 23-335 Charger/Conditioner. I believe I paid about $12 for mine. It charges both NiMH and NiCd. You select battery type with one switch (NiMH or NiCd) and capacity with another (normal or hi-cap).
Charges 2 or 4 "AAA" or "AA" at a time, and shuts off automatically to prevent overcharging.

The only thing with NiMH and this (or any other) charger is DO NOT use the charger's "conditioning" cycle on them.
This feature is only used for NiCd types. What it does is fully run the batteries down, and then charge them back up. This is stated in the instructions, but they don't mention that discharging NiMH all the way to the ground ruins them. X-[

I use NiMH "AAA" cells in my green laser pointer, and they work wonderfully in it.

http://ledmuseum.home.att.net

 

[**DONOTDELETE**]

I think you do need to use a nimh charger for nimh batteries...the odd thing about these chargers is that in spite of some manufacturers calling them "smart chargers" they really are DUMB, in that the ones I've seen do not charge the nimh batteries by sensing their voltage...when you put the batteries in, a timer starts, and goes off after 8 hours for my aa's -- no matter how much charging the battery actually may need which I think is really dumb, since one of the main advantages of nimh batteries is supposed to be that you can charge them after after every use, even if they aren't well-drained, and they won't develop a memory like nicads -- but if you have to charge them every time for a fixed amount of time, you lose the time advantage...any one know of a REALLY smart nimh charger????
(gimme a star somebody...)

 

[**DONOTDELETE**]

Telephony;
A prodigious reply, thanks! (Soundsa little like the 'Eco-charger' I got a couple years ago - which developed CWD or madcow disease or something) -- but knowing Radio Shack to be very fair in their return policy, I'd be willing to give it a try. "Pulse' may refer to PWM type charging; pulse-width-modulation, which all the new solar battery controllers use these days - a way of tapering the charge by some means other than switching the current off and on -- it modulates the frequency thereby affecting the current? or something...
Thanks again.

 

[vcal]

KenBar-
I couldn't agree with you more..
Have used R.SHK #23-410 unit for
th last 2 years and will not use
ANY other charger on my NiCads
or NiMh batts..
Even Hi-Cap batteries can be re-
charged FULLY in 2-3 hours or less..also, with th truly smart/
pulse charging this unit does, u
will get MORE recharges out the
batts. than with el cheapo re-
chargers (which offer false economy).
Good news..GREAT CHARGER!
Bad news...I don't see this unit
listed in the latest catalog anymore!!??
2nd choice recommendation would be R.S. cat.#23-422-I think you
will save more than the extra
cost of these chargers--in the
long run..
These units will severely discourage those nasty memory
problems with NiCads, as well as
rehabilitate most of your older
batts.

Batteryman

 

[e=mc²]

Videocal, I have the 23-422 and it is a great charger. Just some notes after using it for 2 months, if you charge hi-cap NiMh batts, it seems as if the end of charging cycle ends a little prematurely. Simple solution: just start the cycle a second time around. This seems to "top off" the batts to their fully rated capacity. It's no big deal to me since the cycle time on AA NiMh seems to be a brief 1.5 hrs. which will fully charge the 1200-1350 maH variety but the 1600 maH ones that I use (Sanyo), you need this second charging cycle (assuming you start with depleted batts.)

 

[**DONOTDELETE**]

Videocal,
I got the R.S. cat.#23-422- and it worked great! A nice unit, seperate power supply makes a nice compact unit on the desk...I had a couple dozen nicads heading for the trash, based on the 'bad batt.' indicator on my (now trash) 'Eco-charger' -- the Radio Shack unit charged them all in less than an hour per 8 batteries...
Do you suppose the unit does also drain Nimh batteries though??? It seems to have charged mine OK -- but I don't know if it drained them first...

 

[axolotls]

I personally use the MAHA204F charger for AA and AAA. Very pleased, charges in about an hour to 2.5 hours depending on charge. Also comes with a 12V adapter so you can charge up in your car. I warns that the conditioning button should only be used if your batteries aren't up to snuff anymore. Charges at 500mA and has some sorta microprocessor that detects current so you can leave the batteries in the case. This was $30. How much is the RS ones you guys have. I do need one for the C's and D's

 

[**DONOTDELETE**]

I've got the Maha too...I didn't think to dig it out to try it on the nimh's...why not just put your Ds in a battery holder and hook it up to the leads that come with the Maha? I also forgot that the Maha makes the 'conditioning' an option..thanks for reminding me...

 

[axolotls]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Ted the Led:
I've got the Maha too...I didn't think to dig it out to try it on the nimh's...why not just put your Ds in a battery holder and hook it up to the leads that come with the Maha? I also forgot that the Maha makes the 'conditioning' an option..thanks for reminding me...<HR></BLOCKQUOTE>

Hey! What a great idea. Thanks.

 

[vcal]

-Ted,
I don't have the R.S.#23-422unit
but your concern re:"condition-
ing"cycle on Nimh batts.is valid
The unit should have a"disable"
switch/button to bypass that
unwanted function for the Nimh..
Also, NEITHER of the 2 R.S.
chargers use a fixed timer for
the charge cycle-they are made
to sense from the cells directly
when they are ready. (that's why these units are so pricey)
-Hope this helps...

 

[vcal]

-Ted,
I don't have the R.S.#23-422unit
but your concern re:"condition-
ing"cycle on Nimh batts.is valid
The unit should have a"disable"
switch/button to bypass that
unwanted function for the Nimh..
Also, NEITHER of the 2 R.S.
chargers use a fixed timer for
the charge cycle-they are made
to sense from the cells directly
when they are ready. (that's why these units are so pricey)
-Hope this helps...

 

[RonM]

I also have the MAHA204F charger. Bought it based on the recomendations received from digital camera forums. With the way digicams go thru batts, digicam owners have to become battery experts.

I only wish I knew that conditioning shouldn't be done with NiMH's. Anyone know how to tell if a NiMH is ready for the trash? What voltage reading on a fully charged AA indicates that it's no good anymore?

RonM

 

[RonM]

Forgot to mention that one of the best places to get NiMH batts and chargers is Thomas Distributing - http://www.nimhbattery.com/batteries.htm .

They have an excellent reputation.

RonM

 

[The_LED_Museum]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by KenBar:
The new MAHA Ultra High Capacity AAA batteries are some of the best I have had.
<HR></BLOCKQUOTE>

What do you consider "ultra high capacity" in this battery size & chemistry?

The NiMH "AAA" cells I got from Radio Shack marked "high capacity" were 600mAh. They tend to go rather quickly in a laser pointer that draws 400mA.

http://ledmuseum.home.att.net

 

[vcal]

ANOTHER great source if u need
1650mah Nimh AA batts.is Hosfelt
Electronics (listed in Led links)-their cat.2000B-lists
Sanyo's Super Nimh cells @2.65ea
whether you need 1 or 100.
I tried 'em and they're GREAT.
[#33-197-pg.4]
to RonM:
Unfortunately, the only way to
determine when your Nimh cells
are hurt (or"shot") is when they
don't run very long...
-On 2nd thought.., if you have a
light meter and a test bulb of
known load/draw, you could compare the cell with another nu
one or another of known quality.
-that's about the ONLY way you
can get ANY idea of a cell's
health--when it comes to NiCads
or Nimh..
Hope that helps.
I gotta go finish my new mercury
vapor keychain light now-BYE
batteryfanatic

 

[axolotls]

OK. Thomasdistributing has a great informative site; but I'll go ahead and throw in a plug for
http://www.sunnbattery.com

I got my MAHA 204F and 4 AAA Nexcell 650's for $33.99 (w/ DC car kit).

From coast to coast I got it over the weekend (Thursday to Monday)