The folks that I deal with are professionals who hate dealing with equipmen=
t
problems. You are probably right when you say that they don't take care
about the accus as well as you do, but I would never blame them. Usually,
most problems are more important to them than their equipment. Only to get =
a
visa, working permit and flight ticket, for example.
I recently bought an accu and a fast charger for my digital camera. It will
be interesting to see how that one works. Considering the price - 140
dollars for charger and 4 AA batteries, it would be good.
Klas.
At 17:58 2002-06-16 -0400, you wrote:
>Klas Strandberg wrote:
>>
>> Walt,
>>
>> I speak with filmmakers, cameramen (film and video) and lightcrew almost
>> every day. They use the best of chargers and very expensive accus. They
>> report ongoing problems. Every time they throw away a 150 dollar 12V pac=
k,
>> they waist 9 cells just because 1 is blown out completelly. Very trouble=
some
>> for the users and very good business for the pack-makers.
>>
>> I make new cellpacks for them, with loose 6Ah D-size cells and a very si=
mple
>> current limited slow charger. (say 6-15 hours) With loose cells and 2
>> chargers, they can even charge a 12v set from the car battery.
>>
>> I believe in battery packs and fast charge when I see it work on my benc=
h. I
>> admit though, that it works okay when the load is fairly low and the cha=
rge
>> is fairly slow. Perhaps you can thank your HHB for your good experiencie=
s?
>>
>> I use fast chargers only to my cell-phones. I have to buy new packs 2-3
>> times per year.
>
>I use fast charge for everything, except the 9 volt batteries though
>there is a fast charge specification for them too, and the cells that
>I'm now replacing are 5-6 years old or older, with extensive use. I've
>not yet replaced any NIMH batteries, just some of the older Nicads. And
>my oldest NIMH are 3-4 years old. I went to fast chargers several years
>ago when the first of the microprocessor controlled ones came out. Since
>then I've had less cell failure, not more, in fact I tried the new
>chargers on the batch of "dead" batteries I'd accumulated, and quite a
>few the new charger had no problem getting to work again. I keep my
>batteries in groups and charge them in groups, which is equivalent to
>having a bunch of battery pacs. I mark the date on every battery when I
>get it, so I know exactly how old everything is. The HHb uses a battery
>holder for 8 AA's, but it's not a pac, takes loose batteries. Though I
>do keep them in sets of 4 and have two batches of 8 just for it. And the
>HHb is only one of quite a variety of things that I run off
>rechargables. It's not my major battery eater, my lights are.
>
>I actually trust the built in charger in the HHb less than the fast
>chargers. It's a slow charger, but the batteries stay warm even when
>charged, indicating it's trickle charge may be too high. My fast
>chargers the batteries cool to near room temperature after charging when
>left in the charger. Though they are in battery maintaining mode.
>
>I expect that the pacs you make could be fast charged reliably using a
>new charger made for the job. In any case replacing a cell would not be
>a problem on the ones you made. It would be nice for the pac makers to
>put out pacs designed for cell replacement. Older pacs often were held
>together by screws making it easy. Newer ones are more often locking
>tabs and glue to fight.
>
>Part of the problem is that there are many fast chargers that are not
>properly designed, often they are simply timed and little more. Many of
>these fast chargers have settings that are critical, or if they lack
>them they are depending on the operator. That's even more true of the
>elaborate, expensive ones. I don't trust timed charging for fast
>charging, and manual ones you sooner or later forget. It only got
>reliable for me when they added microprocessor control, I used some of
>the older fast chargers, but they had to be watched through the charge
>cycle to be safe, and immediately disconnected from the batteries when
>it was done.
>
>The latest pulsed fast chargers look like they may be even better. Gas
>buildup at the plates is the biggest problem with fast charging, and
>these break up the gas formation. Slow charge produces gas too, but at a
>rate it does not normally build up. This latest style of fast charge may
>eliminate the last bit of physical difference in what happens with the
>two styles.
>
>I certainly agree, if you fast charge at the fastest allowable rate I'm
>not sure you do as well as I do. The folks that run R/C cars and so on
>are the ones I know around here who charge at that rate. While my
>chargers are considered fast chargers, they still take about 2-4 hours
>to charge (depends on the capacity of the battery), considerably slower
>than the high speed fast charging that takes less than a hour. My sons
>had a R/C truck that they charge the main battery pac on a super high
>speed charger, and several of those nicad pac's are several years old
>and still going strong. They get charged in 20 minutes! That charger is
>not microprocessor, but has a settable timer and always discharges the
>batteries first, you have to be careful using it and set the timer for
>less if it's a older pac that's not holding a normal full charge. It
>would be easy to damage the pacs by simply setting a few extra minutes
>on the timer. That sort of overcharging would give exactly the sort of
>symptoms you are experiencing. Particularly when combined with something
>else, which is to chronically drive the batteries right down flat when
>using them. Sooner or later you will reverse a cell doing that.
>
>Note that both my sons and I pay attention, follow the instructions,
>understand what's going on. I'm wondering about the folks you are
>dealing with. I'm thinking they are rushing around thinking about
>anything but proper battery care. The most expensive chargers I know
>about are designed primarily for use by someone who's job it is to
>maintain a large set of batteries for some company or such like. They
>are all manually settable, very capable machines, and results depend on
>both correct setting and correct understanding of the process. They are
>tools for battery pros. Fairly inexpensive microprocessor controlled
>fast chargers designed for the characteristics of the pacs they use
>would be a better choice for your folks. The kind that will do all the
>thinking necessary and adapt to the varying capacity of pacs as they
>age. And learning to not run them into the ground in use would probably
>help a lot too.
>
>Walt
>
>
>
>To unsubscribe from this group, send an email to:
>
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/=
>
>
>
This outgoing e-mail is scanned for viruses with Norton 2002
Telinga Microphones, Botarbo,
S-748 96 Tobo, Sweden.
Phone & fax int + 295 310 01
email:
org. no SE440130067001
________________________________________________________________________
________________________________________________________________________
|