djmp69

For as long as I can remember, whenever I'm charging batteries, (I'm talking NiCd and NiMH) there are commons that I have always seen. A 4.8v pack would get to almost 6v, a 6v pack would get to at least 7.9v. The rated capacity would be almost reached, if not surpassed by a couple hundred milliamps or two. For example, on a 4200 mah pack, I would get consistently 7.8v and 4200-4500 mah, no matter the brand. Now I will say the biggest pack that I'd used up until my latest dilema is a 4200. I recently decided to try 5000 mah packs.

Let me step aside here and say, for this application, I do not care about LiPos, LiFe, Lions, etc. I am not interested in answers about Lithium chemistry.

Now, what I'm noticing with these 5000 mah packs, they are topping out at 7.3 votls, and capacity is topping out at anywhere from 4300-4600 mah. Nowhere near the rated capacity. Again, normally on ANY 6v pack, be it 2000 mah or 4200, I would CONSISTENTLY get at least 7.8-7.9v and at least the rated capacity if not more. I;ve been doing this for a very long time, so I am well acquainted with proper battery etiquette, charging and maintenance. I'm just really put off now though, because these brand new 5000 mah, 6v batteries are performing like batteries that I have had for a few years that have not been well maintained.

I am wondering if this is characteristic of that level of capacity, or is it limitied to that brand of battery? Anyone else experience anything like this?

A. J. Clark

What's your charge rate? Is it proportional to your other batteries? If you bump up the charge current the voltage will probably go up in the end too.

djmp69

I use a 500/500 discharge/charge rate. It has worked for me for many years. From 2000 mah packs to 4200s, I charge at 500 til they peak. The peak is always at the rated capacity or a lil bit more. Then I cycle three times 500/500, and they level out. 6v packs have always peaked at right around 7.9v for as long as I can remember in my 30+ years in the hobby. I always get the rated capacity worst case. But on these packs, which are "fresh from the factory", I'm only getting right around 7.3v 4600 mah peaks at best. I wonder if there is some kind of internal resistance thing going on because of the higher capacity, or is the company simply slapping a nominal 5000 mah label on a 4000 mah pack? Maybe theres a reason D batteries are bigger than C batteries?

djmp69

Plus, I'm more concerned about capacity, since I dont really want my servos getting anything over 7.2 volts. If I bump up the charge rate, I might get a higher voltage, but apparently at the cost of lower capacity reading judging from the performance of these batteries...