Power/Charging circuit for Portable Raspberry Pi - Page 1
Forum section: electronics / projects

author: guycothal
author_rank: Newbie
timestamp: March 28, 2015, 05:08:12 am
content: Hey all,I am trying to make a Portable Raspberry pi. Currently I am running everything with perfectly with the components that I have. Here is where my issue is. I am powering it using a LiPo battery that was recommended from a popular youtuber by name of Ben Heck. He also used the same battery in his project. I am trying to design a circuit that will have the following:DC Input Jack (with switch inside)Master Power SwitchCharging/External Power (will select between charging and powering the unit when external power is connectedLed Indicators (charging/wall power/battery power)currently in the prototype that I have, I just have the battery on the one side of the regulator and the pi/lcd on the other side of the regulator. I have included links to the battery and regulator at the end of the post.Here are the conditions I would like to try and accomplish with this circuit. This is just a rough outline, but I am open to suggestions:Code:Plugged In Master On/Off Charging/Wall power StatusYes On Charging ChargingNo On Charging Battery PoweredYes Off Charging ChargingNo Off Charging Off - Does NothingYes On Wall Power Wall PoweredNo On Wall Power Battery PoweredYes Off Wall Power Off - Does NothingNo Off Wall Power Off - Does NothingWhat i do know is that LiPo batteries have a specific set of conditions in which they like to charge and discharge. This is the only area that i am pretty green in. It does have a build in module that is supposed to handle the charging part for me but I dunno if it will. Can someone help me out here??Voltage Regulator:http://www.amazon.com/5-24V-0-93-18V-Adjustable-Voltage-Module/dp/B00FZSOLTI/ref=sr_1_3?ie=UTF8&qid=1427518226&sr=8-3&keywords=Adjustable+Switching+Power+Supply+Step-Down+ModuleBattery:https://www.amazon.com/gp/product/B002Y2LJW0/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

author: franksanderdo
author_rank: Contributor
timestamp: March 28, 2015, 05:31:31 am
content: Hey Youyour battery does NOT have charge controller build in, only over charge/discharge protection.This makes life pretty easy as you can use a simple 2 cell charge IC i.e. MCP73213.All the BestFrank

author: guycothal
author_rank: Newbie
timestamp: March 28, 2015, 05:47:02 am
content: Quote from: franksanderdo on March 28, 2015, 05:31:31 amdo you think something like this would workhttp://www.microchip.com/Developmenttools/ProductDetails.aspx?PartNO=MCP73213EV-2SOVP

author: franksanderdo
author_rank: Contributor
timestamp: March 28, 2015, 06:12:16 am
content: Hey HoIt will, but it is a little more expensive than doing the circuit your selfIf that is not an issue go, for it.now, as you have a charging unit, you need to figure how to bring things together.Bear in mind you want to be able to switch (battery) power of the pi in order not to drain the battery when the pi is not used.All the BestFrank

author: LukeW
author_rank: Frequent Contributor
timestamp: March 28, 2015, 04:35:36 pm
content: You can get off-the-shelf consumer devices for portable charging and battery extension of your cellphone or similar portable devices, with a built-in USB output port, USB charging port, LiPo battery inside and control electronics. It may be worth looking at simply buying a device like that which is ready to plug in. On the other hand, of course, you may want the challenge/fun of designing and building your own thing from scratch.