OT: Ni-MH Battery Charging

Fyron · #1 July 29th, 2005, 11:57 PM

I have a Panasonic Ni-MH battery charger that was purchased with 2100 mAh AA Ni-MH batteries. It's output is listed as 1.5 V and 550mA x4. I bought some more batteries today made by the same company. They are 2300 mAh batteries. Will there be any problems associated with charging them in the charger I have? How about using them in the same device with the 2100 mAh batteries? I believe both sets of batteries have 1.2V.

Slynky · #2 July 30th, 2005, 12:12 AM

I had some concerns, too, when I needed to replace my 1700 mAh batteries for my camera (wouldn't hold a charge very long). Looking for replacements, I couldn't find them anymore. Wolf sold me some but they were 2300, I believe. I took them back (I only looked at the voltage which was the same). Then I scoured the net for exactly the batteries I had but no luck. Finally, I ordered from Olympus and got 2100 mAh versions. The guy from Olympus told me the same thing the guy from Wolf did...that the increase in mAh would not be a problem and would hold a longer charge. I've been using them without any problems. They DO hold a longer charge.

So, that's one vote for "no problem".

Slick · #3 July 30th, 2005, 03:25 AM

mAh = milli-Amp-hours

This is basically the capacity or endurance of the battery. Theoretically, A 2100 mAh battery is rated for putting out 2100 mA for 1 hr or 1 mA for 2100 hrs or anything in between. In practice, these extremes are not encountered and generally a battery will last longer at lower discharge rates.

The device doesn't know/care what the amp-hr rating of the battery is. What does matter is the voltage rating. So long as the voltage rating is the same, the device will draw rated current until the battery is depleted; at which time the output voltage drops significantly. Some "smart" devices will sense the voltage droop characteristics of the battery and give warnings or "charge level" indicators.

edit: same goes for the charger; not a problem. It will charge to full capacity regardless of the rating.

An AC adapter basically converts AC to DC at the required voltage; the device "sees" an infinite battery hooked up, but can't tell the difference between the AC adapter and a battery. That is until you stop paying your electric bill, the next hurricane, etc...