question about battery charger in host...

[WonHungLow]

I've got some Max 1811 single cell charger ICs that I've used for a while and have thought about integrating one into a single cell host. The only part I'm unsure of is how to use it in circuit. What happens when u start charging the battery. Is there a type of switch or diode needed. I know some DC barrel jacks will connect one pin when plugged in and disconnect when unplugged but I don't have any just lying around. I just have standard 3.5mm jacks and similar. I'm sure someone has done this before its avaliable in commercial flashlights and lasers just haven't seen any in the DIY circle. Any input is appreciated

 

[BShanahan14rulz]

I imagine if nothing's plugged into the barrel jack, it won't be a complete circuit, so the charging circuit wouldn't get energized even if you turned on the device. Also, if the device is off and you are charging the battery, the device's switch is off, and usually that is just in series with the rest of the circuit, meaning the other circuit is open and not energized.