-->
Page 1 of 2

Rechargeable batteries and load sharing

PostPosted: Tue May 12, 2015 3:16 am
by dayzman
Hi

I'm hoping to use 2x 18650 3.7V (in parallel) and enable load share, i.e. if USB is plugged in, draw from USB - otherwise draw from battery. Does anyone know how load sharing in this setup could be accomplished?

Thanks

Re: Rechargeable batteries and load sharing

PostPosted: Tue May 12, 2015 3:20 am
by torntrousers
Using something like these?

Re: Rechargeable batteries and load sharing

PostPosted: Tue May 12, 2015 3:29 am
by dayzman
torntrousers wrote:Using something like these?


I've had a look at this one but I'm not quite sure what the output voltage is. Is it 3.7V?

In fact, would 3.7V need to be stepped down for the ESP?

Thanks!

Re: Rechargeable batteries and load sharing

PostPosted: Tue May 12, 2015 5:04 am
by villTech
dayzman wrote:Hi

I'm hoping to use 2x 18650 3.7V (in parallel) and enable load share, i.e. if USB is plugged in, draw from USB - otherwise draw from battery. Does anyone know how load sharing in this setup could be accomplished?

Thanks
simplest way to do it is to add a small relay, energized when usb is plugged. relay contact will do the power selection switch. you can also add the 18650 charger from the link above, to charge your batt when
when usb is plugged.

but instead of relay, it be better if you use a mosfet to switch power from the batt. and transistor is cut offed when usb power is applied