Series?? Parallel??

[stangster]

1. Can someone explain to me in layman terms what the difference is between the two. I'm referring to nimh battery chargers. Is one better than the other? Advantages? Disadvantages? How do I know what is what if the charger doesn't say what kind it is?

2. Also what do I need to look for in a charger if I want to charge 1 battery? I hear some chargers can't charge only 1. Why is that?

3. Does question 1 have anything to do with question 2?

 

[obeck]

Quick Example: two 1.2 V 2000maH batteries
in series: the provide 2.4V @ 2000maH
in parallel: they provide 1.2V@ 4000maH
The above have ignored discharge characteristics and internal resistance for simplicity sake.

for chargers: many chargers will only charge pairs of cells, so you should try to get two similar cells to avoid overcharging one while they both charge. Other chargers will charge individual cells to their max potential. yes, question 1 and question 2 are related

 

[FalconFX]

Series chargers are a bit more temperamental than parellel chargers. Reason being is that not only do they charge 2 cells in order and the risk for reverse-charging is there, if you have an odd number of cells to charge, you're SOL if you can't find a similarly discharged cell to compliment a dual bank. Series chargers gather a charge current similar to 2.8-3.0V per dual-bank and usually charge in pairs at a time. Current is split between the number of banks provided.

Parellel chargers charge cells quicker if they have less cells: for instance, 2 cells will charge quicker than 4 cells in a typical parellel charger. They still run the same risk for reverse-charging, and they are also prone to over/under charge a cell if one cell of an entire chain link is defective. Parallel chargers are either dual banks or, like the CCrane, can charge semi-independantly. Current is divided by how many banks are filled, and as in the case of the CCrane, 4 batteries will split current 4 ways, 2 batteries 2 ways, and the lesser the battery you have, the more current is distributed to a cell...

Independant channel chargers avoid the reverse-charge problem. And if you have a defective cell, you avoid damaging other cells while that one is isolated in an independant circuit. In the case of the Maha C401FS, each channel is provided an independant voltage and current flow...

All three chargers have their pluses and minuses. But I believe independant channel chargers make parellel and series chargers inferior because of its capability to charge in singular, isolate a dead battery, and avoid reverse charging as well as charge odd numbers at the same time.

 

[stangster]

FalconFX,

Thanks again for the info. All I basically want is a charger that will charge different sizes, charge 1 batt if I want to, have some sort of charge cut off, be able to detect a dead or messed up cell, charge a high cap "D" cell fully and allow me to be able to "set it and forget it". You recommended a Vanson in a different thread. I can't remember the model but it's the one that's $40.

Is this the one I want?

 

[FalconFX]

Stangster, the Vanson 1HU is probably the closest model... I wouldn't pass over the CCrane, though, as this charger is just as effective, even though it's a quasi-independant channel charger.

Both chargers are at or under $40. Both can charge anywhere from 1 to 4 batteries. However, you may realize that the Vanson has a timer around 11-12 hours, to turn itself off to avoid a runaway charge. This is prevalent in most smart chargers, so within that period of time, just take the batteries out and reput them back in to reset the timer and you're set...

I'd say if you're not going to mix different capacity batteries, then go for the CCrane, as it allows you to view and check the voltage of your batteries. But if you're going to mix, say a AA, a AAA, a C and a D all together, or maybe 2 AAs and 2 Ds, then I'd suggest the Vanson or even the Rayovac PS3 (which also has independant channels)...