To add to that, something like the NCP140x or MCP1624 might be a good fit depending on your current requirements. Both are relatively cheap (< CAD$1 from Digikey in single units) and require only a few passive components. I've used the MCP parts on a LiPo design, but they'll be equally happy with AA batteries. I have the NCP1400 on a Sparkfun breakout and it appears to work . Both have relatively low maximum currents at ~200mA at reasonable voltage if memory serves, but that's generally not a design consideration with the capacity of the cells mentioned, so maybe that's okay? -m On Tue, Feb 5, 2013 at 2:17 PM, Marc Nicholas wrote: > Hi Josh, > > I might be stating the obvious here, but wouldn't this be an ideal > scenario for a switching boost regulator? > > -m > > On Tue, Feb 5, 2013 at 2:11 PM, Josh Koffman wrote: >> Hi all, >> >> As part of the project I'm working on, I'm trying to figure out the >> best way to power it via batteries. In previous projects I've used >> small LiIon and LiPo cells, which have worked quite well for my >> purposes. My applications are typically medium-low drain (say, under >> 300mA max), and the cells I've gotten have worked well, powering the >> device for the desired amount of time before requiring a recharge. >> >> For my current project, I'm thinking about switching to AA NiMH cells. >> The advantage here is that high capacity rechargables are readily >> available (~2500mAH), and if all my cells end up flat, I can switch to >> alkalines with no problem. The problem here is that I was hoping to >> use 4x AA batteries, which while taking up a good amount of room in a >> beltpack style case, is manageable. Due to the cell voltage of a NiMH >> cell, I don't think I'm going to get enough input voltage that I can >> then regulate to a nice 5V. I could go up to 6 cells, but it starts >> taking up a lot of space. >> >> I'm curious what other people have done in this situation. I could go >> to two LiIon or LiPo cells in series, but the cylindrical cells are >> too large for the capacity I'm looking for, and rectangular cells >> aren't easily swapped out (ie no one makes a holder for them). >> >> Any thoughts? >> >> Thanks! >> >> Josh >> -- >> A common mistake that people make when trying to design something >> completely foolproof is to underestimate the ingenuity of complete >> fools. >> -Douglas Adams >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .