Car charger design

Posted by: junchan1122 on 01/20/2011

Halo PI-Experts,

I m trying to design a charger for charging car battery which is about 12V 40AH. Is PI product fits this application? One thing I don't understand that for those design examples with CC/CV charger adaptors, it is necessary to add an external cct to cut the charging voltage when the battery is full. Otherwise, the battery may over charged? And,,,can those PI chargers be used to charge NiMH battery?

Thanks.
Jun.

Comments

PI products can not deliver 12V at 40 amps
The CC mode of the battery charger is to limit the amount of current you are using to charge the battery. This current is specified by the battery manufacturer.
During CV mod the battery is already charged but not at his full. During this part of the charging process, the voltage is kept constant to avoid to exceed the specified battery voltage.

Thanks....PI-Worf,

So,,,can I make a 12V 4A charger to charge the battery for 10 hrs? And,,should I increase the charging voltage slightly higher than 12V,, i.e.13V to make the battery fully charged?

Regards.
Jun.

Heh, car battery must charged by current app. 0.1C, i.e. 4 amp, you'r right. But finally battery voltage must be app.14.4V. So you can charge battery at fix voltage - 14.4(14.8 may be) and charge current will change from your current limit (4Amp) to a negligible value at full charged battery.

Thanks a lot SNS.

Hello, I think car charger must be light and covenient to take away. The another problem is that car charger should be easy to handle, not too complex for users. I bought a bestek 400w power inverter from its official site in three months ago. Maybe you can know more about this inverter on Bestekmall. Hope this point is useful to you. Have a nice day.