Why does my C204F take longer to charge one side?

[BatteryCharger]

I have a Maha C204F charger that I use for all my NiMh batteries. I almost allways use 4 batteries at a time (from my digital camera) and almost allways the 2 batteries on the right side take longer to charge - sometimes up to a half hour or more. Why is this?? Is something wrong?? I'm worried it might be over or under charging one set of batteries...

 

[Bullzeyebill]

I have not noticed this situation with my 204F. Have not really paid attention. Check voltage of all 4 batteries fresh off charge. Overcharging can result in higher initial voltage.

Bill

 

[SilverFox]

Hello BatteryCharger,

I would suggest that you check the voltage of the batteries when taken from the camera. Take the two lowest voltage ones and put them into the left side to see what happens.

Quite often batteries are not depleted at the same rate. If you are a creature of habit, you could be placing the cells in the charger the same way each time.

Tom

 

[drs2000]

Haven't seen one of these chargers before, but a Nimh charger needs to sense temperature of the cells. Look in the charge slots and see if you see a small hole with a little matchhead looking thing in it. Usually near the center, and slightly protruding. If there is something like this, then see if there's a difference between the two sides, ie, pushed in further, etc. This is reaching, but you never know. Look for any sign of a temperature detector.. In the Nomad Jukebox, it's a small black bead, Say half the size of a matchhead up near one end of the slot, between the two cells. If it gets pushed in, it'll sense slower than the other side.. Worth a stab.

Yours, drs the crazed, probably biting off my foot again..

 

[BatteryCharger]

[ QUOTE ]
If you are a creature of habit, you could be placing the cells in the charger the same way each time.


[/ QUOTE ]

They usually get put into a pile with other dead batteries until I charge them up, so I doubt this happens. I will measure the voltage before and after though next time...

[ QUOTE ]
Haven't seen one of these chargers before, but a Nimh charger needs to sense temperature of the cells.

[/ QUOTE ]

This charger does not have a temperature sensor.

 

[Doug Owen]

As a guess, one side has a higher charging current than the other. This current wouldn't necessarily be all that well controlled, maybe 20%?

You should be able to measure it, if it really troubles you.

Doug Owen

 

[JSWrightOC]

This is a little off topic, but you might want to also consider marking your cells in sets of however many your digicam uses (4 from what I can infer). This way, the same cells will be exercised the same amount, and charged together. If you take two cells of different charge levels and install them in a series-type charger (such as the C204, oppose the C401) you can overcharge one cell and undercharge the other. Using an independent-channel charger would fix this, but you still woudln't be exercising them together. Just a thought. /ubbthreads/images/graemlins/smile.gif

 

[kitelights]

Re: Why does my C204F take longer to charge one si

You seem to be a more than casual NiMH user. While the 204 was the top charger in its day, the 401 has outgunned it by a long shot. Just the ability to charge all fours cells independantly makes the upgrade worthwhile, and there are quite a few other improvements, too.

The behavior that you describe is the start of how my 204 finally bit the dust. Maha was great and replaced it for free, but after talking to their techs, I bought the 401 and never use the 204.

The better and higher the capacity your cells are, the more you need a high quality cutting edge charger.

 

[eluminator]

Re: Why does my C204F take longer to charge one si

I think it's important to keep sets of cells together. I have two sets of 4 for my camera and several sets of two for most other things. I use the plastic battery holders from Thomas Distributing to keep the sets together.

This tends to keep the capacity of each cell in the set about the same. This is important when you discharge more than one in series in whatever device you use them in.

Even in the best of circumstances, one cell will have less capacity than the rest. As the cells discharge, that cell will lose voltage the fastest. If discharged too far, the voltage of the weakest cell will go below zero, reverse polarity, and damage will be done.

Mixing cells with a different history, brand, capacity, etc. exacerbates the problem of uneven capacity.

I'm so particular about this that when I buy more batteries, I buy a different brand. That makes it easier to keep track of the sets.

The problem of unequal capacity is there even with alkalines. You don't care if the weakest alkaline is ruined by reverse polarity, of course, because it's dead anyway, and you just throw it away. But the weak cell driven below zero volts, could leak.

 

[Brock]

Re: Why does my C204F take longer to charge one si

I tend to group my cells in sets of 4 since they is the most used size. I use colored markes and make 4 red, 4 black, 4 blue and so on so I can keep them all seperate, but still dump them all in one (waiting to be charged) bin.

 

[liquidium]

What is the advertised capacity of your cells in mah? All the same? Were they purchased during the same rough time period, or a year or more apart? Do you use one set more than another, even w/out realizing it? The last two of these factors could result in the reduction of your batteries' capacity, and therefore a reduction in max charge times - making it appear as if your other batteries "take longer" to accept a complete charge.
Nimh cells with a higher mah capacity take longer to charge because they are capable of accepting more current from the charger.
Still, you mentioned that this consistently happens on one side of the charger only. FWIW, my c401fs never lies - three green lights and one red can only mean the remaining cell is no more than 5 minutes or so behind the others.