ORIGINAL: Hefeman
I believe the good sgt is talking about me. I bought 2500 mah aa's off eBay and they lasted about 1 5/6 gallons, after cycling them twice. But to clarify one thing, I read on brand x batteries website awhile back that most alkaline aa's are 2500 mah. However, since there are only 4 cells (1.5 volts x 4 =6 compared to 1.2 volts x 5 =6) the rx pack will should last a while longer with the additional cell, provided it has a high mah rating. I have never even tried to run off regular aa's, but I am really surprised that they would only last a couple of tanks... they should be about the same as a 6 cell 1800 provided they are mounted where they will not short out. Of course one other problem with alkalines is that the voltage drop under load is fairly steady, where with Nimh's, there is an initial drop, then almost none untill near complete discharge. This is the likliest culprit, perhaps the rx doesn't work well with voltages below say 5.3 or so volts.
Yes, I was refering to you.
When the batteries are wired in parallel like they are in a batt pack, the longer runtime dosn't depend on the # of cells. In seris it does. Think of it this way.
You know who in a car you can power, or speed? (depending on the gearing. If you gear it low, you have maximum torque, but less top end, and vice versa.) Well it's the same with batteries, where mah is the power and volts is the speed. You can only have one or the other, not both.
So parallel makes speed, not power. In other word it adds the voltage of the cells, but has the same mah as only one of the cells. With seris, it takes the power, not speed. So if you have 5 1.2v 2000 mah batteries and you wire them in parallel, you get a batt pack with 6 volts, but 2000 mah. If you wire them in seris, you get a pack with 1.2 volts, but 10000 mah, or 10 amps.
So the extra cell dosnt contribute to run time, it gives more volts, because NiMH's need that extra cell, because they only run at 1.2 volts, instead of 1.5 that a alkaline runs at. But the NiMH's DO last longer because of the initial drop thing you said.
Of course one other problem with alkalines is that the voltage drop under load is fairly steady, where with Nimh's, there is an initial drop, then almost none untill near complete discharge.
Just to clarify things up a little.
