wkng Posted January 26, 2005 Report Share Posted January 26, 2005 Hi i am doing a project to use a rechargable battery while charging it at the same time. Can anyone help?? Quote Link to comment Share on other sites More sharing options...
mixos Posted January 26, 2005 Report Share Posted January 26, 2005 First of all you must define the type of the battery you want to use. It will be NiCd, NiMH, Li-Ion or another? Quote Link to comment Share on other sites More sharing options...
audioguru Posted January 26, 2005 Report Share Posted January 26, 2005 Hi Wkng,You won't be using the battery while charging it. You will be using any extra power from the charger. If the charger doesn't have any extra power to supply your project and charge the battery, your project might not work properly and the battery won't get charged.If you use a powerful power supply to do both, you must limit the charging current especially when your project is turned-off. Also, the charging voltage is higher than normal so your project might need a voltage regulator during charging. Then the voltage regulator will be backwards between the battery and your project when the charger is removed, and will need to be reversed or removed.It would be a lot easier if your project can run from the higher voltage from the power supply, and still work properly from a slightly lower than normal battery voltage. Then the charging current limiter can simply be bypassed with a diode when the charger is removed. Quote Link to comment Share on other sites More sharing options...
MP Posted January 26, 2005 Report Share Posted January 26, 2005 Wkng,As you can see, this is not a general question. Do you have a schematic of the charging system on this device? If it is a commercial unit, perhaps it can be found on the internet. If you can post more information regarding this, I am sure you can get help on this. It is a simple task but there are several ways to go about it depending upon the present hardware.MP Quote Link to comment Share on other sites More sharing options...
ante Posted January 26, 2005 Report Share Posted January 26, 2005 If the battery type requires constant current charge it won Quote Link to comment Share on other sites More sharing options...
mixos Posted February 5, 2005 Report Share Posted February 5, 2005 I came across bq24100 datasheet and i thought it may interests you. This is a Li-Ion switchmode charge management IC. Take a look here:http://focus.ti.com/docs/prod/folders/print/bq24100.htmlIn page 25 of datasheet there is circuit using bq24100 that charges the battery while powering the system without affecting battery charge and termination. Search for other charge ICs that you could be used this way. Quote Link to comment Share on other sites More sharing options...
audioguru Posted February 5, 2005 Report Share Posted February 5, 2005 Thanks, Mixos,TI's charger circuit is sensing the battery's voltage and current separate from the load. Quote Link to comment Share on other sites More sharing options...
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