How to measure voltage and current of lead acid battery?

[rajsundar08]

frndz
i wanted to measure battery charge voltage and current of lead acid battery of current voltage value 48V,10A . i am using PIC as brain . how can i get it done ????
please help me in this regard..

what sensor shall i use 4 current measurement ??? or else when its sense resistor of 1 ohm,480W
how to connect it with microcontroller ???

thanx in advance
rajsundar
Mod: Always write headings in Detail. Just Writing "doubts in" will make most of the memebers just ignore your post.Anyways its changed now.

 

[sakhan]

Why don't you use a Rogowski coil to measure the current.

 

[pranam77]

frndz...i wanted to measure battery charge voltage and current of lead acid battery of current voltage value 48V,10A . i am using PIC as brain . how can i get it done ???? please help me in this regard..
what sensor shall i use 4 current measurement ??? or else when its sense resistor of 1 ohm,480W...how to connect it with microcontroller ???
thanx in advance
rajsundar

You may use the PIC's ADC to measure the voltage and use a load across to see the health of the battery while powering. You may use a shunt in series to the load and connect the ADC across the Shunt which will also monitor the current supplied to the load. A resistor of 1 Ω 480 watts will be as big as your table...

 

[FvM]

Why don't you use a Rogowski coil to measure the current.

Do you know how to measure a DC current with a Rogowski coil? I'm curious.

 

[CrabMan]

or you can size the sensing resistor appropriately and use hcpl7840, and then use the ADC to measure the voltage drop across sensing resitor

 

[sakhan]

You can get an idea about rogowski coile from the following link
**broken link removed**

 

[ProEngineer]

A 1 ohm resistor is pretty high value for a shunt resistor. We usually use a .1 ohm or smaller resistor for measuring currents. We sometimes use a copper trace on the PCB. I'd suggest using a 'High-Side Current-Sense Amplifier' go convert the voltage drop across the resistor to a easily measured voltage. One that we use a lot is the Maxim MAX4173.

 

[karesz]

Max is a good IC & their are some other chips too, as Allegros bipolar sensor: ACS706, w*w.allegromicro.com/en/Products/Part_Numbers/0706/0706-20A.pdf, on the market...
K.