problem with MCU

[caramelz]

Hi everyone, I'm designing a battery charging system. Now my batteries are connect to AN0 which is RA0 to read the voltage in order to display in the LCD. But now the problem is that I have to charge the batteries. I'm afraid that once I supply voltage to the batteries. the voltage will flow to the MCU pins which is RA0, RA1,RA3,RA4,RA5. Can anyone tell me what should i do ???

 

[kubeek]

Which MCU? Schematic?

 

[caramelz]

this is the schematic for the reading the voltage of the batteries. I'm using Microcontroller MPLAB, pic18f4520, mcc18 compiler. now I need to connect the charging kit into this schematic circuit. Hope you can help me out.

 

[dr pepper]

Its early in the morning here so it might be me, but it looks like you've drawn a circuit that will destroy your relays, the common and n/o contacs are wired accross each battery, which will be shorted as soon as the relay closes.

You can measure the voltage of the battery while its charging, so long as the volatge divider reduces the voltage to lower than 5v, or the voltage reference your using, protection diodes to the supply rails might also be good.

 

[caramelz]

so the batt (+) connect to NO but the (-) has to go somewhere else? i only want to reader the battery when the relay=0, please teach me what to do. now i'm stuck on the connection for the charging kit. I need to use 8 batteries.

 

[dr pepper]

No disrespect however I think you need to learn a little more about electrical basics before tackling this project.

 

[BeerBelly]

I see you have 1 relay for 2 batteries. Is the relay to switch from one battery to the other?

 

[georgetwo]

YOU have to give a clear description on what you intend to do.
block diagrams will not be a bad idea