Voltage measurement

[Knappolean]

Built a maybe 2 6AAx2D adapters according to instructions, they work great. Measuring end to end voltage reads 8.2-8.4 VDC using eneloops
This seems high considering 7.2 should be norm? Any Info would be appreciated. Last electronic experiance was with Ben Franklin and the kite. Both rinkey dink multimeters showed basically the same.:shrug:

 

[Turbo Guy]

This seems high considering 7.2 should be norm?

1.2 V per cell is the nonimal voltage and really indicates a discharge cell. A fully charged Ni cell will be in the 1.4 to 1.45 range so 8.4-8.7.

 

[2xTrinity]

1.2 V per cell is the nonimal voltage and really indicates a discharge cell. A fully charged Ni cell will be in the 1.4 to 1.45 range so 8.4-8.7.

Agreed. The idea of the nominal voltage is that if you connect your battery to a load, between the time you start to drain your cell, and the time it it completely spent, on average it will be delivering 1.2V/cell). The way disposable batteries, such as alkalines, are reported are in terms of their starting voltage -- which is around 1.5V. In reality, the difference between them is a lot less than that. NiMH actually do start out at close to 1.45V/cell and shuld terminate at around 0.9V/cell (average of 1.2).

Also, there is an effect called voltage sag as well. When a battery is connected to a high-current load, there will be some voltage dropped due to internal resistance. In the case of alkaline cells, this internal resistance will be much higher than NiMH cells, so in a high drain application where the alkaline has a cripplingly high amount of internal resistance, the TRUE effective voltage (under load) will actually be higher from a "1.2V" NiMH cell, than a "1.5V" alkaline, for the vast majority of the runtime.

 

[Knappolean]

Thanks, I thought something was wrong with my Meters.
Info is easy if you know where to find it.