question Differences between Sanyo's AA eneloops and Panasonic's AA eneloops?

LunarMist

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#42
Probably more significant is the fact that the Sanyo NC-MQNO6U is only a dual-channel charger. On top of that, it's a 'slow' charger, taking 10 hours to fully charge. Although there's some mention of being a 'smart' charger, Negative Delta V isn't reliable with low charge rates, so it's more likely the charger relies on a timer and temperature monitoring. This type of charger is not friendly to NiMH batteries, but cheap to make.

The Panasonic BQ-CC55 is a proper smart charger with 4 independent channels, although power supply limitations mean it takes twice as long for 4 batteries as 2. I would be favoring this charger for all the batteries, if possible. If you need to use the NC-MQNO6U, try to keep the batteries in pairs (label them) and don't mix them up.

You can crudely compare cells with a multimeter. You want each pair to have a similar voltage at full charge and when at least half discharged.
Do you have the BQ-CC55? I've been trying to find good, lightweight travel chargers, yet they seem to have one issue or another.
That Panasonic one should be fine for four cells at 750mA. However, the charge times listed imply that 1-2 cells would be receiving twice the current of 3-4.
If true, the 1.5A rate would be undesirable in hot regions with no A/C. :(
 

time

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#43
No, but here is the full specification.

What really caught my eye was the fact that this is a variable current charger! Although the average for two cells is 1.5A, the peak is 3.2A! I assume that after stabilization, the charger increases the current and monitors the battery temperature. When temperature reaches a certain point, the charger starts dropping the current, obviously to way below 1.5A.

It's always been conventional wisdom that NiMH should be charged with a constant current until negative delta V occurs. The Maha charger probably takes this to the point of obsession (yes, I have one).

I would love to get my hands on one of these to see it in action. Might be hard to measure the current on something that's effectively monitoring impedance though.
 

LunarMist

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#44
No, but here is the full specification.

What really caught my eye was the fact that this is a variable current charger! Although the average for two cells is 1.5A, the peak is 3.2A! I assume that after stabilization, the charger increases the current and monitors the battery temperature. When temperature reaches a certain point, the charger starts dropping the current, obviously to way below 1.5A.

It's always been conventional wisdom that NiMH should be charged with a constant current until negative delta V occurs. The Maha charger probably takes this to the point of obsession (yes, I have one).

I would love to get my hands on one of these to see it in action. Might be hard to measure the current on something that's effectively monitoring impedance though.
Based on the charge times, I expect that the peak power is only temporary. For example, "The quick diagnosis in Approx.3 seconds at charging start selects suitable charging method by battery voltage and temperature."

With any luck I can pick up the charger on Saturday.
I have a MH-C204W, but it is only for pairs of cells and likes to cook them. It's a bit heavy even with a stub plug instead of a cord.
The other Mahas are big home/office chargers with power adapters.
 
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LunarMist

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#45
The Panasonic charger is fine and charges 4 cells as quickly and fully as one would expect at 750mA. The charge time for 2 cells is on the short side and they are quite warm, like the stupid MAHA.
 

Stereodude

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#46
In order to fully change NiMH batteries they're going to get warm. There are some chargers that will thermally throttle the charging current at the end so they don't get as warm by monitoring the battery temperature, but that makes it harder to detect the -dV peak.
 

LunarMist

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#47
In order to fully change NiMH batteries they're going to get warm. There are some chargers that will thermally throttle the charging current at the end so they don't get as warm by monitoring the battery temperature, but that makes it harder to detect the -dV peak.
Sure, but 4x AA charge just fine at ~3 hour rate. I would prefer the option to charge 1-2 cells at the same rate as 3-4.
I have not tried starting with four and removing two to see if the rate changes. I would not expect that, but who knows.
It would not be unusual for me to charge three cells, one pair from GPS and one single from a light.
 
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