I recently bought four Radio Shack NiHM batteries and, after discovering one of them was bad, I returned them for a new set. This set hardly survives an 8-meg card's worth of pix on my Olympus 600, while the Olympus batteries I got originally last through many sessions. I searched the forum and found Dave's reference to the Radio Shack batteries and then some info on other brands posted by other people. However, the posts were old and I'm looking for suggestions that come of more recent experience.

First, is it just me, or are other folks experiencing poor quality in the Radio Shack batteries?

Also, being a technical ninny, I've looked at fast chargers vs. slow chargers, but can't figure out what I'm supposed to want. The Olympus battery charger I have is, I believe, the fast sort (a couple of hours). Can I (or should I) use them with any sort of NiMH batteries I buy? Or would I be better off getting a different charger?

Recommendations, please! (Battery brands & chargers)

Thanks to any and all who can help me find the confidence to purchase with a bit of intelligence.

-- Barbara Coultry (bcoultry@nycap.rr.com), July 22, 1999

Answers

A warning to all: I got a bit carried away, as usual, so get a cup of coffee before you start. The good stuff, not decaf... :-)

I'd return the Radio Shack batteries and try the Thomas Distributing link on the front page of the Imaging Resource. Radio Shack gets WAY too much for their NiMH's. You can get 4 AA Nexcell NiMH's from Thomas for under $10. Less, if you order in a larger quantity.

I have a Toshiba PDR-M1 and waited until after I got it to buy the rechargeables. Results with the better branded Alkaline AA's were dismal so I gave the Nexcells from Thomas a try after doing quite a bit of research and reading on the subject(see Tinhuat Oh's page, search the forum or tips page/archive). The GP batteries are supposed to be quite good as well. The Nexcell results are astounding! I can EASILY get 200 shots with BOTH LCD & Flash!

I bought eight Nexcell AA's, and the cheap $9 maha charger from Thomas. Don't expect the charger to charge the batteries very quickly(36-48 hrs), but it's fantastic in that you can leave a set plugged into it all the time so there's always a set topped off and ready to go. (Dave once mentioned he does the same as do several others from past forum posts. Very handy!) To make up for the dismally slow performance of the very cheap MaHa trickle charger, I bought a Radio Shack, Cat#: 23-406, NiCD/NiMH 5 Hr. battery charger. This is a nice simple little timed charger that does a very good job(I believe it does switch to a trickle mode after charging, despite no mention of this function, since the batteries are very slightly warm even several days after charging, if left in the unit.) It is switch selectable for NiCD or NiMH with the only difference being that the timing period is a bit shorter for the NiMH setting and the current is a bit higher. I regulary use the NiCD setting, which charges at a lower current so the batteries don't heat up very much, which takes a bit longer(another hour or two), but yields a very nice charge. Once they're done, I pop them into the MaHa and leave them plugged into the wall to top off and stay trickle charged. It's not as convenient as having a single charger that switches to trickle(it may, I just haven't verified it with a meter) when the batteries are done, BUT I get to keep one set trickle charged and charge another set at the same time for less than a good combined unit would have cost from Thomas!

In fairness, it may be worth looking at the chargers on Thomas's site, since they were waiting on several combo battery/charger units from GP when I bought my cells and charger.

The best way to see how well the batteries are charged, without actually taking pictures and keeping track of how many you get, is to buy a reasonably cheap DC voltmeter or digital multimeter(possibly from Radio Shack) and just measure the cell's voltage after removing them from the charger. My Nexcells top out at about 1.412 - 1.414 VDC when fully charged without any load connected(as measured with a pretty accurate Fluke Multimeter.) I realize this may be a bit too TECH-NERD-NOIREish for the average consumer, but hey, it's hard to beat when actually trying to see how well things are charging or charged. :-) You can also gauge how well the cells are charging by checking the voltage across a cell in the charger when you start and then checking it again nearer the end of the charge cycle in most chargers since they are usually constant current charging circuits. To maintain a constant current charge the voltage must generally ramp up as the charge cycle progresses.

Another thing to remember is that NiMH's suffer from a fairly high self discharge rate. What this means is that even a fully charged NiMH left sitting on a shelf, or in a camera, will lose charge. Generally, a 10-20 day period will drain at least half(or probably more of) the battery's capacity. So it becomes important to keep the NiMH's stored in a trickle charger. NiMH's can be charged at 1/10th their rated current capacity for at least a year straight without any damage according to the manufacturers! Another thing to consider is that NiMH's can be charged before they are completely discharged, but this should only be done in a trickle charger or in a charger which can monitor the cell voltage(a delta-V charger) and shut off the charging current at the right point. Charging partially charged cells in a timed charger could(and probably would) allow them to overcharge which can lead to overheating and venting! YEEEEUK!

Some people still like to drain the cells down, at least periodically, between charges to help prevent "memory" problems, but it probably isn't very necessary. I do it once in a while, but only by turning the camera back on and letting it shut itself off again a couple of times. Draining the cells to too low a voltage can damage them, so be careful if you use other methods to do this. Generally speaking, memory effect has been greatly exaggerated over the years. It's only actually been demonstrated to exist once, by General Electric or a subcontractor, in a solar charging system used in an early satelite and is only thought to have occured because of the extreme regularity of the charging cycle. Most experts seem to agree that the effect most people call memory is actually a result of OVERCHARGING and can easily be beaten by using the cells and properly recharging them a few times.

Good Luck. If anyone has any questions concerning this, yell, and I'll try to answer them, if I can. I did do a bit of research on this, since I'm considering building/possibly selling some Delta-V fast charge/trickle charge NiMH chargers.

-- Gerald Payne (gmp@francorp.francomm.com), July 22, 1999.

Barbara,

One thing I forgot to add, is if your charger is designed to charge NiMH's it should work with all brands as far as I know. You can see how good a job it does by checking the terminal voltage of the cells after they're removed from the charger with a meter as referred to in my original post. If your charger does a good job with NiMH cells from Olympus it should do a good job with other NiMH cells. The only trouble you might run into is if your charger is designed to charge very hi-capacity cells and happens to only be a timed charger it may overcharge cells having a lower amperage capacity. Kind of unlikely, but possible, I suppose. You should be able to tell if this is the case by reading the capacity usually stated right on the cell's outer shell or packaging.

-- Gerald Payne (gmp@francorp.francomm.com), July 22, 1999.

My Radio Shack NiHM batteries are fine. They work about the same as the Quest batteries that came with my camera. I don't undersatnd all of the concern over battery life. At 10-20 bucks a set who cares if they take 50, 100 or 200 pictures? I have no idea how many pictures I came take on a charge, but is is way more than 12, 24 or 36 exposures that I get from film. I just buy more batteries and keep several charges sets. Of course you would want to return them if you think you have a bad one.

-- Don Edgar (deldon@teleport.com), July 22, 1999.

In answer to the last posting, believe me, when your batteries hardly make it through 8 to 10 high-quality pix, you start getting pretty darned annoyed.

And in response to our hyper coffee drinker, I plan on showing your e- mail to my husband who will surely understand all the information you gave. (As I mentioned, I'm a ninny about technical things, particularly electrical things.) I certainly understood enough of it to realize that, first, we don't always get what we pay for, and, second, that I'd be a lot happier with a charger that I could leave the batteries in.

Thank you for all the info and the recommendations. Now off to get my husband to explain the more technical stuff to me.

-- Barbara Coultry (bcoultry@nycap.rr.com), July 22, 1999.

What? Me, a hyper coffee drinker? Nah, I hardly ever touch the stuff. I'm hopped up on Pepsi, the official drink of all hacking- engineering-nerd-weirdo types world 'round... I intended the coffee to help keep anyone reading my reply awake long enough to get through it! ZZZZZzzzzzzzz... :-)

One thing I did forget was that you really have to give NiMH's a complete charge before their first use. They may even need a few charge-discharge cycles before they will hold a full capacity charge.

It sounds like the batteries you got from "the Shack" were either part of a bad or damaged batch or hadn't been fully charged. Maybe your charger didn't like them for some reason? I do remember Tinhuat Oh having problems with some chargers/battery combinations or perhaps with a couple of faulty chargers [BAD QC(Quality Control)?], but your results are about as bad as alkaline use in some cameras. I seem to recall having a hard time filling an 8MB smartmedia in my PDR-M1 with a set of alkalines with LCD & flash. Probably due mostly to the high current demand when recharging the flash, although the LCD backlight is probably pretty hungry too.

Try recharging the Shack's cells and checking them with a meter. Perhaps there's another bad cell that isn't coming up to anywhere near the same terminal voltage as the others. If so, you know the drill, just hop into the Delorean and it's, "Back to the Shack, Part 47..." :-)

Good Luck

-- Gerald Payne (gmp@francorp.francomm.com), July 22, 1999.

Thank you people so much. This is EGG actly what I needed to know. Good Deal Lucille!!!!

-- Sherry Frazee (spf55@earthlink.net), January 13, 2003.