I am using a sim900 module in the following link and I connect it to my laptop using USB to TTL converter and the module works properly. But, when I connect the same module to 9V DC battery the module keeps restarting, and also if I power the module from my laptop via usb cable it also keeps restarting. So, please, help me out.
GSM module working when powered by laptop via USB but keeps restarting when powered by battery
batteriesgsmpowerttlusb
Related Topic
- Sim800 restarts on battery but works fine on power supply
- Electronic – USB to TTL communication problem
- Electronic – SIM800C GSM module works via PC but not on battery
- Electrical – Can’t type on Virtual Terminal Proteus
- Electronic – arduino – How to automatically disconnect from battery when USB +5v is present
- Electronic – USB and Battery switching circuit not working [and buck boost converter not working either]
Best Answer
A USB device can only draw 100mA by default, during enumeration you need to request the maximum of 500mA for USB 2 and below during device enumeration. So when connected directly to the power pins you can only draw 100mA. I couldn't see a current specification for that board but most GSM modules are closer to 500mA than 100mA.
For a Energizer 522 Alkaline battery the maximum current draw appears to be around 500mA so that might be one option although the lifetime will be relatively short. PP3 batteries generally don't have very good current draw characteristics, personally I'd probably look at using something rechargeable like 6 x AA NiMH cells, or maybe AAA if size is a bit of an issue. LiPo packs that are commonly used in remote controlled cars etc may be another option.