Cell-meter

[lovefool]

The new product has been released in Japan, that is Cell-meter4 and 8. When you connect this Cell-meter to the Lipo balancer connector, and it will show the voltage of each cell, and fuel gauge on LCD.

I am wondering how to determine remaing fuel on the Lipo. Is remaing power can be determined by only voltage of each cell?

http://www.ep-plane.com/cellmeter/ (in Japanese)

[Noto]

Probably by measuring the voltage with a load.
I don't know how accurate it would be tho.

It is probably a rough estimate at best considering there are my variables in a pack that would effect voltage from manufacture to manufacture.

This is just a guess of how it works tho considering I can't read Japanese :)

[lovefool]

Someone has already opened Cell-meter and took pix. (Not clear pix tho)
One is the main board, and the other is LCD. The main board has componets on only one side.

[Rodney]

On both Lithium and lead acid batterys, open circuit voltage is a quite reliable indicator of state of charge. You can also get a good idea of the internal resistance by measureing a no-load voltage at the cell terminals and then the voltage with a known load. The no-load voltage minus the loaded voltage divided by the load current give a good approximation of the internal resistance.