Need a new charger for AA NiMH batteries

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I bought some cheapie PowerBase brand batteries a while back that have
been fantastic, however they have finally died. Use the batteries on
my camera flash (canon 430ex). I am going to go out and by some more
powerbase batteries tomorrow (unless someone suggest a better brand)
and would not mind buying a decent charger. The charger I have is a
pretty cheap piece of crap, so I figured replaceing it wont hurt. Any
suggestions? I know nothing about NiMh chemistry and recharging, so
figured this might be the place to ask.

Phil, waiting on your flames!

Re: Need a new charger for AA NiMH batteries



"The Real Andy"
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** I charge my NiMh AAs with a home brew, bench PSU that has a continuously
variable voltage and current limit.

400mA for about 5 hours is the go, I reckon.

When they feel a tad warmish  -  they're cooked  !!

Never owned a commercial battery charger in my life.

I cook my own pizzas too.



.....   Phil




Re: Need a new charger for AA NiMH batteries



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I used to work for a company that imported and sold cordless  phones wth
NiMH batteries.

We were getting battery failures or faulty batteries....  I designed a "MEGA
battery charger tester" for 5- batteries

The design used a LM317T in a constant current circuit 20mA..... worked a
treat.

See these web links
http://www.electro-tech-online.com/general-electronics-chat/24616-lm317-constant-current-questions.html
http://users.telenet.be/davshomepage/current-source.htm
http://www.wiparat.com/constant-current-circuit-with-lm317 /

Use  a 10th of the mAmp/rating  for an overnight ~ 14hour charge

Joe



Re: Need a new charger for AA NiMH batteries



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Oh whoopsie do!
In one of your toasters?



Re: Need a new charger for AA NiMH batteries



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I'd have a close look at Sanyo Eneloop batteries before you do.  I think
some of the generic makers are copying them now.

Biggest problem with rechargeables in my camera, is that I use it lots, I
have 4 sets of batteries, but often there are many weeks in between and
the self discharge of normal rechargeables is atrocious.  I always had
half full batteries, and had to charge fully before use - and how do you
know you are going to need it in 2 days time - ridiculous situation.

The Eneloops are amazing, totally different situation.  They are always
nearly full, and I don't have to know that I am going to use them tomorrow

With the number of rechargeable devices in this house, not having low
self discharge batteries is asking for lots more work.

Cheers, Colin
Melbourne

Re: Need a new charger for AA NiMH batteries




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I don't use my camera that much, but I had the same experience with
Eneloops. I had ordinary NiMH batteries  (Jaycar "Powertech") in my
Canon camera. Half the time when I wanted to use the camera, they
would let me down. I had to resort to always taking a spare set of
alkaline AAs with me.

About a year ago I changed over to Eneloops and they are way better. I
have only charged them two or three times since I got them - each time
just before I knew I was going to be using the camera more than usual
(old habits die hard).

Just recently I needed some more to use in another camera. I
considered getting some "Eneloop copies" that I happened to see at
Aldi. I decided not to take a punt on those as DSE (sorry, DS) had
real Eneloops for not that much more.

Andy Wood
snipped-for-privacy@trap.ozemail.com.au

Re: Need a new charger for AA NiMH batteries


On Sat, 18 Jul 2009 21:33:25 GMT, snipped-for-privacy@trap.ozemail.com.au (Andy
Wood) wrote:

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My batteries in the flash cop a good hiding. I think I have had about
3 years usage from the current lot. I thought they were stuffed but it
turns out it was the charger. The charger is designed to charge AAA
with an inbuilt adaptor that flips down, up is AA, down is AAA. The
must have been some issue with the contacts, because after I flipped
it down then back up it started charging the batteries.

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