Hello Guys,
thanks for the replies. The battery I am talking about is a 12V 18AH Deep Cycle Exide Battery. I am trying to create this circuit for a FIRST robotics competition. The batteries are usually used up very quickly. When being used by the robots, they only last minutes. This circuit is supposed to be a "give away," something my team can give to other teams as a gift. Therefore I can't make it to complicated or expensive.
My circuit is very coarse, but it is just a rough indicator of which batteies are used, and which are already charged... basically.
Klaus, I understand your concern that it will be somewhat unaccurate and REALLY COARSE.
Also, the circuit is not permanetly connect to the battery. It is just hooked up for a few seconds to determine the charge.
Russlk brough up a major flaw...
A red LED drops about 2 volts, so only the two left most LEDs will light on a full charge.
Major problem, If I use for example a 8, 9, 10 and 11V zeners, I won't have this problem, right?
Would really appreciate your help.
thanks a lot,
George L.