Tphage

Battery Cell Voltage Measurement : "Accuracy" of Various Measuring Devices.

I checked a single battery with various voltmeters or voltmeter functions of e.g. battery chargers. Not that it matters particularly but the battery was a Zippy Compact 3S 40C 3300 mAh from Hobbyking.

The voltage of the three cells was measured on each device and I did two trials, measuring the battery on all the devices once ( Trial 1 ), then again in the same order ( Trial 2 ). I am not going to list the results of Trial 2 as it becomes too unwieldy to view and to the hundredth of a volt, they were identical anyway.

I don't have a calibrated voltmeter so I interpret the results by looking for closeness of readings between the various devices. And I'm not going into accuracy and precision because it makes my brain hurt. It's not a valid scientific test of each device in general because it is based on only one or two examples of each - that's all I had - but it still provides some indication. ( And incidentally, for anyone wanting a lowish-cost battery checker for the field, I can recommend the dlux Turnigy "Auto Checker" Cell Checker Auto Balancer - from HobbyKing. You simply plug in the battery balance lead and it shows all the cell voltages instantly on the one screen as well as the remaining battery capacity. )

The first column is the device used and the next three numbers are the measured voltages of cells 1, 2 and 3.

1) Imax B6 AC V2 battery charger ...................................3.79, 3.80,3.80
2) Imax B6 AC V2 battery charger No. 2 ...........................3.80,3.80,3,80
3) Icharger 308 Duo battery charger Channel 1 .................3.794,3.794,3.792
4) Icharger 308 Duo battery charger Channel 2 .................3.795,3.793,3.793
5) HobbyWing Multifunction LCD Program Box ...................3.74, 3.78, 3.78
6) dlux Turnigy "Auto Checker" ........................................3.79,3.79, 3.80
7) dlux Turnigy "Auto Checker" No. 2 ................................3.79,3.80,3.79
8) Aokoda Low Voltage Buzzer Alarm.................................3.78, 3.80,3.80
9) HobbyKing Cell Checker ..............................................3.79 , 3.79, 3.79
10) HobbyKing Cell Checker No.2 .....................................3.79, 3.79, 3.78