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Old Oct 28, 2004, 6:41 AM   #21
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photog180 wrote:
Since we're on the topic,I have both the C401FS & C204W chargers.I'm not overwhelmingly impressed with either. C204W:- Flashing Yellow-Discharge|RedFast Charge|Green-Trickle Charge. On its Discharge/conditioning cycle it stops,shows red very briefly & within literallyminutes shows green.Meaning it's bottomed out on its discharge cycle but instead of fast charging for a reasonable period of time it's gone straight into 50mA trickle mode.If the lights are functioning correctly the Batts have got no hope of gaining a reasonable charge in a reasonable time.I have 2 204W both consistently showing the above behaviour on all channels.
Users who have C204W should reply to this also, and say whether they experienced the same.

I can only ask you - are you generally sattisfed with power and endurance of batteries after they're recharged with C204W?

and... Did you contact manufacturer and asked them about this issue, that would be good idea.
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Old Oct 28, 2004, 7:17 AM   #22
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I agree it's difficult to determine if discrepancies in charging time is due to various tolerances in each battery being charged. However, one thing I did notice that I neglected to mention earlier might be a slight problem. Once all banks show a trickle charge, in both fast and slow mode, if I take out the batteries and reinsert them in different banks usually I'll get one or two that show a red charging light for as long as a couple of minutes to +10 minutes. I'm assuming this is a circuitry issue but not a defect. Just as there are slight difference is tolerances in batteries I'm sure the detection, charging and other various electronics needed to properly charge a battery has its own - but in the end all batteries charge and perform well. I don't think I could say the same thing (but could be wrong) with dual or single charging devices.

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Old Dec 19, 2004, 4:49 PM   #23
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I have the C204W. I have had the same problem (Yellow-discharge to Red-fast chargeand to green- fulll charge shortly after the red lights go on). This problem does not happen everytime I do the discharge cycle. I called MAHA and they told me it was a battery problem (New Batteries). They told me that when batteries are in the "new" stage they can give a false "full" signal because they are still in there "Break-In" period. Since I only have had this problem just a few times I tend to think it is a battery problem also. The batteries charge just fine in the regular charge mode. I think the C204W charger is a very good charger. If anyone has any comments on the C204w charger I would like to hear them. Thanks.

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Old Dec 19, 2004, 7:48 PM   #24
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I own the C204W charger and can say that I am most pleased by it. I am not sure if I have used the conditionning on any batteries yet, but if I did it was on some old batteries.

I tried to charge my 1600 mAh batteries with it and there were no problems, they just got pretty hot. But I find that its better than nothing, since my charger inside my discman had gone crazy and did not charged my batteries anymore. I used my MAHA charger on the batteries once and it has awaken the batteries and now they can still be charged in my discman integrated charger. I realize that this charger is surely not the best, but I don't like to charge my batteries below 2000mAh in my C204W, since they get hot and since I prefer to monitor the batteries during the charge.

Anyway, I love that charger, it doesn't have a huge plug and can go anywhere in the world... And I plan to make it see a few places!
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Old Jan 11, 2005, 1:18 PM   #25
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I have used the Maha 401 for more than a year and have recently bought one of the new 204W chargers. A few thoughts:

a) Pulse-charging: Based on the research I've seen, this may or may not provide a benefit in the real world. It does appear to improve the performance of the batteries as you get deep into their life cycles (500+) charges. While that could be important in Hubble Telescope batteries, it's probably not that big a deal for consumer batteries at $10 a set. However, pulse charging is certainly a good approach.

b) Fast charge: From everything I've read, you want to charge NiMH batteries as fast as possible with a reliable end of charge detection. No consumer battery charger has an absolutely ideal end of charge detection as you would really like to have a thermocouple heat sensing circuit in addition to Delta-V detection. However, since we are stuck with Delta-V, fast charging makes the detection more reliable.

c) This whole heat issue is a red herring. First, when battery manufacturers cite a 50 degree C max, they are talking about the ambient temperature. For peak temperature during charge (for peak detection), they suggest a 55 or 60 degree temp. Honesty, if charging the batteries hot reduces life span by 10% (say from 600 to 550 charges), does it really matter? If you charge the batteries once a week, that's TEN YEARS. Even if you charge them every day, that's still TWO years. Someone using batteries that intensely can probably afford to buy a new set for $10 every year or so! Keep in mind that the faster (and hotter) you charge these things, the more reliable the Delta-V detection works.

d) In my experience the 401 is a great charger. Yes, you do see a few minute difference in the four cells -- more noticeable in slow charge than in fast. I would be surprised if you DIDN'T see slight differences. After all, each cell is slightly different with difference discharge and charge characteristics. Likewise, I'm sure the precise values of resistors used in the four detection circuits varies a bit -- it's inevitable unless you want to pay for mil-spec matching. Big deal. That's the whole point of independent circuits.

e) Real world benefit of independent circuits? Have you ever given your wife four batteries to use in her Discman on a trip? Does she come home and dump four batteries out of her purse? Any idea which ones belong in a pair? Which one's are charged? Which ones are discharged? With the 401, it doesn't matter. Just stick them in the charger; doesn't matter.

f) I haven't used the 204W as much, but I am impressed with it as well. To me, it provides essentially the same performance, minus the independent circuits but plus the discharge feature. I bought it for easy travel.

g) Real world benefit of discharge feature? If you always use your batteries until the camera or device shuts down from low voltage, then you don't need this feature. However, if you routinely "top-off" batteries that have been on the shelf or have only been slightly discharged, then it is probably a good thing to run them through a discharge cycle down to 1 V every once in a while. You could do this with a discharge cycle or in a single-cell flashlight or even putting them in a Discman and running the thing until it shuts off. All the discharge feature does is run down the batteries. It's convenient in the charger, because the charger automatically switches to charge mode, so you can do the whole cycle overnight. But, there are other ways to skin the cat.

h) Most of the anomolies with NiMH batteries occur when they are brand new (or when the voltage has dropped below .5 V).Simply put, the voltage curves on brand new batteries are squirrelly until they've been charged and discharged a couple of times. Specifically, new batteries sometimes fool the chargers into thinking the battery is fully charged before it is. Just charge a new set, run them down, and charge them again. BTW, this highlights an advantage of the independent circuits. Without independent circuits, a squirrelly battery in a pair is going to impact the charging (and discharging) of the set.

I'd recommend either of these chargers. Whether the discharge feature or the independent circuits is more important depends on how you use your batteries. Or, do as I did and buy one of each. I'm not suggesting that Maha chargers are the only good chargers out there. To the contrary, I think most of the high current Delta-V detection smart chargers work just fine. I do think the Maha product is nicely made, works as advertised, and has a nice set of real-world features. But, honestly, this isn't rocket science and the minute differences touted in the reviews and advertising claims don't add up to much in the real world.

Hope this helps.
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Old Jan 13, 2005, 6:14 PM   #26
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Would discharging the batteries using flashlights damage the batteries? I recall reading that NiMH batteries should not be discharged below 1volt.

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Old Jan 13, 2005, 10:20 PM   #27
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Discharging them too far in a multi-cell flashlight can cause problems. Discharging them in a single-battery flashlight is supposedly A-OK, although chargers sometimes get confused by a battery that is completely discharged (say below .5 volt).
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