When rechargeable batteries started coming back into fashion a few years ago I got all excited and started buying them. I am not impressed. For the most part they suck. At least the ones I have bought. I have tried the off brands and the good ones (Energizer). They just don’t work. The one exception is my GPS, in which rechargeable batteries actually seem to last longer than alkalines.
I have always used Energizer slow chargers. The first one would occasionally destroy a batch of batteries by not shutting off when the batteries were fully charged. When I discovered it the batteries were hot and ruined. So I bought a new, better charger- this one hasn’t destroyed any batteries yet but it frequently runs into some type of problem and instead of charging them flashes a light indicating a problem. If this happens I can sometimes find and remove the offending battery and it will charge the others. Then sometimes I can put the offending battery back in with another batch of batteries and it works fine. But all of this trouble hardly seems worth it, especially since some things don’t work well with them, presumably due to voltage differences.
Sometimes they work OK, but it doesn’t seem like the benefit is worth all the trouble. Am I doing something wrong? Is there a better brand? Anybody have trouble-free experience with these things?
Depends on the application. For digital cameras, if you’re not using rechargeable batteries then you’re just throwing away money. I’ve used 3 sets over the past 4 years with no problems, not sure why you are having so many problems.
Try Sanyo Enloops, which hold their charge much, much, longer then regular NiMH batteries.
In many cases the problem with rechargeables is that they are really too small for what they need to power but manufacturers design things that way because people will buy the smaller camera or whatever over the bigger one every time. The result is that the batteries are just too small, they discharge too fast and are then recharged too fast. One of the worst examples are laptop computers but also video cameras. In some cases I just resort to carrying a large battery pack on my belt and things work way better.
Bad chargers are also sometimes to blame. The slower the charge the better and, in fact you can charge batteries at C/20 for 24 hours or more and not really have to worry about overcharging. I do this all the time. And the charger is just a resistor in series with some wallwart.
I have a USB charger I got from Xtreme Geek. It has a normal and rapid setting; it holds two at a time either AA or AAA. I have never, ever had any trouble with it. It came with two generic rechargeable batteries that are still working two years later. (even in my camera!)
I’ve been using rechargeables for years - Rayovac and Energizer brands. Never had a problem, never had to throw them away. I don’t go through them like candy, but almost certainly one full charge a month. YMMV
Yeah. I discovered with dSLRs, the rechargeables last much longer than the equivalent single-charge alkalines. We’re talking like 5 or more times as much as the alkalines.
I have a Energizer universal charger. I have both energizer and dynex NiMH batteries, and I’ve never had any major problems. Maybe after a few years a pair of batteries will wear out. I use AAA, AA, and D in a variety of devices. I also have a digital camera with a battery pack that I have a seperate wall charger for, and that seems to work fine as well. The batteries last a long time, and tend to hold a longer charge than regular batteries. I’m not sure what your issue is.
The only thing I can recommend is - I had heard that it’s best to keep pairs of batteries at the same charge level, so I put different color marker or tape on each pair of batteries so that they always get charged at the same time and don’t get mixed up with another pair with a different charge level.
I would have thought exactly the same as you, but I’ve done this on more than one occasion. When I used my D200, I would often use the 6 AA battery adaptor in my vertical grip instead of the proprietary batteries. I found I could get about 1000-1200 shots (one working day’s worth) before having to change them. On one assignment, I forgot my rechargeables at home, so I had to go out and buy a bunch of AAs. I bought four or five four-packs of the best Energizers I could find. The first bunch lasted about 180 frames. The second batch lasted around 200 frames. Luckily, I had someone bring me my rechargeables, so I didn’t run out of juice.
That was the second time it happened to me, and that was when I realized it wasn’t a fluke. The first time was a year or so before that, when I bought non-rechargeable AAs because I thought they would last longer. I remember being surprised they ran out in short order, but thought I just got a bad batch or something. Apparently not.
I have a Lacrosse charger, I highly recommend it, it individually charges up to 4 batteries and has a test mode to give you the mAh of each cell on a LCD display. Multiple charge modes, and most of the time you just put the battery in and don’t deal with settings. When you do want to change the settings it is pretty easy.
Not necessarily. NiCds, for example, “prefer” a fast charge (if performed correctly), as it minimizes crystalline formation. A fast charge also imposes a higher charge efficiency factor.
In order to do a fast charge on a NiCd, however, you need a “smart” charger that will begin to automatically throttle back the current after the percent of charge goes above 70%.
Those are very good. Another brand that makes great chargers and batteries is Maha/Powerex. I happen to like this one. It has three modes: regular charge, quick charge, and recondition. Reconditioning has resurrected some old batteries of mine, and I like the fact that I can charge eight at a time.
You’re correct, but there’s two reasons why alkalines don’t do so well in digital cameras.
Firstly, the higher internal resistance of alkalines means that for high current applications, the alkaline cells waste a lot of their energy as heat in the cells themselves. Not sure how big an effect this is though, since I’ve never looked up the numbers or run any tests.
Secondly, and I suspect this is by far the bigger factor, is that NiCad and NiMH rechargables have a fairly flat discharge curve, and the camera electronics are paranoid about killing a cell. So if the camera figures just one of your four NiMH cells has dropped from 1.2V to 1.1 V, it will register low battery and shut down. Which is good for NiMH cells since you don’t want the other three forcing current through an empty cell, but also means that a partly-discharged set of alkalines will register low battery with plenty of life left in them. Alkalines still have about half of their usable energy left when discharged to 1.1 V.
In the past, when I’ve been a long way from a charger for days at a time, I’ve used two sets of four alkalines but replaced the old set one cell at a time, letting each new cell bump up the total voltage so the camera is happy.
This squeezes the remaining energy out of the half-used alkalines, but you’ve got to be careful not to force current through a fully-discharged alkaline and risk the battery leaking. These days I’d just use high capacity rechargables and maybe carry a spare set of lithiums.
Which makes me think that whenever I have looked for data on batteries, alkalines and rechargeables, I always have much difficulty finding anything. I do not understand why they are not ordered to publish some standardized data so one can compare brands.
At the very least, they’re still the battery chemistry of choice in many handheld power tools. My one month old Craftsman cordless drill has a 19.2 volt battery pack full of NiCd cells. Craftsman makes an optional Li-ion battery pack, but it’s quite expensive. To my knowledge, the vast majority of drills on the market today use NiCd batteries.
There you can see NiMh have a remarkably flat discharge voltage compared to alkalines. Alkalines start out at 1.6 and are considered exhausted at 0.8 V whereas NiMh useful range is more like 1.3 to 1.1 volts
It would be interesting to compare similar sized batteries, say AA, in NiMh and in alkaline to see their capacities, internal resistance, etc.
Those documents compare alkalines with carbon-Zn and NiMh with NiCa but there is no comparison between alkalines and NiMh.
I have a camera which shuts down way too early with NiMh batteries and the problem seems to have been getting worse. I need to try it again with alkalines and see if it works better. Maybe I should do some bench testing as to shutdown voltage, consumption, etc.
I was not aware NiCads were still being widely used. I have no idea why as NiMh are clearly superior in every respect. Maybe Nicads are just very cheap?