Looking for a fuel guage for my battery

[hardenc10]

Does anyone know where I can get a fuel guage to read charge levels in my batteries??

 

[Gristle]

Is this even possible? AFAIK there is no way to measure the power remaining in a battery. At most you could monitor the voltage and know when it starts to fall off, but the types of batteries used in PV's do a good job of keeping a fairly constant voltage output right up to the end. Laptops and other devices like cell phones usually present a "fuel gauge" that works by keeping track of how much power is used for how long, basically a sophisticated timer.

 

[hardenc10]

what about this Fuel Guage

 

[hardenc10]

just found it. Should work on something like this LI-ION Battery Pack

 

[sierra22]

there's a thread on this somewhere around here.... even called it a fuel gauge....

 

[CraigHB]

Externally, you can measure voltage with DMM to get a good idea. For something built into a mod, you might have a little trouble finding something compact enough. If you're willing to build one, there's lots of Li-Ion "fuel gauge" chips available that can drive an LED bar or LED array. If worse comes to worst, you rig up a simple battery low indicator with an LED and zener diode.